Nano-Micro Letters

Nature-Inspired Upward Hanging Evaporator with Photothermal 3D Spacer Fabric for Zero-Liquid-Discharge Desalination

Ye Peng, Yang Shao, Longqing Zheng, Haoxuan Li, Meifang Zhu, Zhigang Chen — Wed, 06 Aug 2025 00:00:00 +0000

While desalination is a key solution for global freshwater scarcity, its implementation faces environmental challenges due to concentrated brine byproducts mainly disposed of via coastal discharge systems. Solar interfacial evaporation offers sustainable management potential, yet inevitable salt nucleation at evaporation interfaces degrades photothermal conversion and operational stability via light scattering and pathway blockage. Inspired by the mangrove leaf, we propose a photothermal 3D polydopamine and polypyrrole polymerized spacer fabric (PPSF)-based upward hanging model evaporation configuration with a reverse water feeding mechanism. This design enables zero-liquid-discharge (ZLD) desalination through phase-separation crystallization. The interconnected porous architecture and the rough surface of the PPSF enable superior water transport, achieving excellent solar-absorbing efficiency of 97.8%. By adjusting the tilt angle (θ), the evaporator separates the evaporation and salt crystallization zones via controlled capillary-driven brine transport, minimizing heat dissipation from brine discharge. At an optimal tilt angle of 52°, the evaporator reaches an evaporation rate of 2.81 kg m⁻² h⁻¹ with minimal heat loss (0.366 W) under 1-sun illumination while treating a 7 wt% waste brine solution. Furthermore, it sustains an evaporation rate of 2.71 kg m⁻² h⁻¹ over 72 h while ensuring efficient salt recovery. These results highlight a scalable, energy-efficient approach for sustainable ZLD desalination.

Highlights:
1 Successful fabrication of photothermal 3D polypyrrole polymerized spacer fabric with excellent water transport capability and high solar absorption efficiency.
2 The upward hanging model evaporator with reverse water feeding achieves an optimized solar evaporation rate of 2.81 kg m⁻² h⁻¹ with minimal heat (0.366 W) loss at a 52° tilt.
3 A mangrove leaf-inspired upward hanging model evaporator design separates evaporation and crystallization zones for zero-liquid-discharge desalination.

Bioinspired Precision Peeling of Ultrathin Bamboo Green Cellulose Frameworks for Light Management in Optoelectronics

Yan Wang, Yuan Zhang, Yingfeng Zuo, Dawei Zhao, Yiqiang Wu — Tue, 05 Aug 2025 00:00:00 +0000

Cellulose frameworks have emerged as promising materials for light management due to their exceptional light-scattering capabilities and sustainable nature. Conventional biomass-derived cellulose frameworks face a fundamental trade-off between haze and transparency, coupled with impractical thicknesses (≥ 1 mm). Inspired by squid’s skin-peeling mechanism, this work develops a peroxyformic acid (HCOOOH)-enabled precision peeling strategy to isolate intact 10-µm-thick bamboo green (BG) frameworks—100 × thinner than wood-based counterparts while achieving an unprecedented optical performance (88% haze with 80% transparency). This performance surpasses delignified biomass (transparency < 40% at 1 mm) and matches engineered cellulose composites, yet requires no energy-intensive nanofibrillation. The preserved native cellulose I crystalline structure (64.76% crystallinity) and wax-coated uniaxial fibril alignment (Hermans factor: 0.23) contribute to high mechanical strength (903 MPa modulus) and broadband light scattering. As a light-management layer in polycrystalline silicon solar cells, the BG framework boosts photoelectric conversion efficiency by 0.41% absolute (18.74% → 19.15%), outperforming synthetic anti-reflective coatings. The work establishes a scalable, waste-to-wealth route for optical-grade cellulose materials in next-generation optoelectronics.

Highlights:
1 First successful peeling of bamboo green into micrometer-scale optical films (10 μm) via a bioinspired peroxyformic acid strategy, achieving intact preservation of monolayer cellular structure.
2 Scalable and stable peeling process enables high-yield production of bamboo green frameworks, demonstrating significant potential for sustainable optical material applications.
3 Experimental validation in light management shows 0.41% absolute photoelectric conversion efficiency enhancement in solar cells, proving practical value as high-performance optical films.

Multifunctional MXene for Thermal Management in Perovskite Solar Cells

Mon, 04 Aug 2025 00:00:00 +0000

Perovskite solar cells (PSCs) have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency (PCE). However, heat accumulation under continuous illumination remains a critical bottleneck, severely affecting device stability and long-term operational performance. Herein, we present a multifunctional strategy by incorporating highly thermally conductive Ti₃C₂T_X MXene nanosheets into the perovskite layer to simultaneously enhance thermal management and optoelectronic properties. The Ti₃C₂T_X nanosheets, embedded at perovskite grain boundaries, construct efficient thermal conduction pathways, significantly improving the thermal conductivity and diffusivity of the film. This leads to a notable reduction in the device’s steady-state operating temperature from 42.96 to 39.97 °C under 100 mW cm⁻² illumination, thereby alleviating heat-induced performance degradation. Beyond thermal regulation, Ti₃C₂T_X, with high conductivity and negatively charged surface terminations, also serves as an effective defect passivation agent, reducing trap-assisted recombination, while simultaneously facilitating charge extraction and transport by optimizing interfacial energy alignment. As a result, the Ti₃C₂T_X-modified PSC achieve a champion PCE of 25.13% and exhibit outstanding thermal stability, retaining 80% of the initial PCE after 500 h of thermal aging at 85 °C and 30 ± 5% relative humidity. (In contrast, control PSC retain only 58% after 200 h.) Moreover, under continuous maximum power point tracking in N₂ atmosphere, Ti₃C₂T_X-modified PSC retained 70% of the initial PCE after 500 h, whereas the control PSC drop sharply to 20%. These findings highlight the synergistic role of Ti₃C₂T_X in thermal management and optoelectronic performance, paving the way for the development of high-efficiency and heat-resistant perovskite photovoltaics.

Highlights:
1 Incorporating Ti₃C₂T_X nanosheets enhanced perovskite thermal conductivity (from 0.236 to 0.413 W m⁻¹ K⁻¹) and reduced operating temperature by ~3 °C under illumination, mitigating heat-induced degradation.
2 Ti₃C₂T_X offers multiple additional functionalities, including defect passivation, improved charge transfer efficiency, and optimized energy level alignment.
3 Champion power conversion efficiency (PCE) reached 25.13% (vs. 23.70% control). Retained 80% PCE after 500 h at 85 °C/RH = 30 ± 5%, outperforming control (58% after 200 h). MPP tracking showed 70% PCE retention after 500 h in N₂ (vs. 20% control).

Nanosized Anatase TiO2 with Exposed (001) Facet for High-Capacity Mg2+ Ion Storage in Magnesium Ion Batteries

Fri, 01 Aug 2025 00:00:00 +0000

Micro-sized anatase TiO₂ displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg²⁺ in anatase TiO₂ lattice. Herein, we report that nanosized anatase TiO₂ exposed (001) facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg²⁺ ion storage. First-principles calculations reveal that the diffusion energy barrier of Mg²⁺ on the (001) facet is significantly lower than those in the bulk phase and on (100) facet, and the adsorption energy of Mg²⁺ on the (001) facet is also considerably lower than that on (100) facet, which guarantees superior interfacial Mg²⁺ storage of (001) facet. Moreover, anatase TiO₂ exposed (001) facet displays a significantly higher capacity of 312.9 mAh g⁻¹ in Mg–Li dual-salt electrolyte compared to 234.3 mAh g⁻¹ in Li salt electrolyte. The adsorption energies of Mg²⁺ on (001) facet are much lower than the adsorption energies of Li⁺ on (001) facet, implying that the Mg²⁺ ion interfacial storage is more favorable. These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions. This work offers valuable guidance for the rational design of high-capacity storage systems.

Highlights:
1 Nanosized anatase TiO₂ exposed (001) facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg²⁺ ion storage.
2 Anatase TiO₂ exposed (001) facet displays a significantly higher capacity of 312.9 mAh g⁻¹ in Mg–Li dual-salt electrolyte.
3 The adsorption energies of Mg²⁺ on (001) facet are much lower than the adsorption energies of Li⁺ on (001) facet, implying that the Mg²⁺ ion interfacial storage is more favorable.

Quantum-Size FeS2 with Delocalized Electronic Regions Enable High-Performance Sodium-Ion Batteries Across Wide Temperatures

Tue, 29 Jul 2025 00:00:00 +0000

Wide-temperature applications of sodium-ion batteries (SIBs) are severely limited by the sluggish ion insertion/diffusion kinetics of conversion-type anodes. Quantum-sized transition metal dichalcogenides possess unique advantages of charge delocalization and enrich uncoordinated electrons and short-range transfer kinetics, which are crucial to achieve rapid low-temperature charge transfer and high-temperature interface stability. Herein, a quantum-scale FeS₂ loaded on three-dimensional Ti₃C₂ MXene skeletons (FeS₂ QD/MXene) fabricated as SIBs anode, demonstrating impressive performance under wide-temperature conditions (− 35 to 65 °C). The theoretical calculations combined with experimental characterization interprets that the unsaturated coordination edges of FeS₂ QD can induce delocalized electronic regions, which reduces electrostatic potential and significantly facilitates efficient Na⁺ diffusion across a broad temperature range. Moreover, the Ti₃C₂ skeleton reinforces structural integrity via Fe–O–Ti bonding, while enabling excellent dispersion of FeS₂ QD. As expected, FeS₂ QD/MXene anode harvests capacities of 255.2 and 424.9 mAh g⁻¹ at 0.1 A g⁻¹ under − 35 and 65 °C, and the energy density of FeS₂ QD/MXene//NVP full cell can reach to 162.4 Wh kg⁻¹ at − 35 °C, highlighting its practical potential for wide-temperatures conditions. This work extends the uncoordinated regions induced by quantum-size effects for exceptional Na⁺ ion storage and diffusion performance at wide-temperatures environment.

Highlights:
1 Quantum-scaled FeS₂ induces delocalized electronic regions, effectively reducing electrostatic potential barriers and accelerating Na⁺ diffusion kinetics.
2 The free charge accumulation regions were formed by edge mismatched atoms, activating numerous electrochemically sites to enable high-capacity Na⁺ storage and ultrafast-ion transport across wide temperature range (−35 to 65 °C).
3 The FeS₂ QD/MXene anode delivers superior wide-temperature capacity of 255.2 mAh g⁻¹ (−35 °C) and 424.9 mAh g⁻¹ (65 °C) at 0.1 A g⁻¹. The FeS₂ QD/MXene//NVP cell achieves a record energy density of 162.4 Wh kg⁻¹ at − 35 °C.

Lattice Anchoring Stabilizes α-FAPbI3 Perovskite for High-Performance X-Ray Detectors

Tue, 29 Jul 2025 00:00:00 +0000

Formamidinium lead iodide (FAPbI₃) perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product (µτ), making it as a highly promising candidate for X-ray detection application. However, the presence of larger FA⁺ cation induces to an expansion of the Pb-I octahedral framework, which unfortunately affects both the stability and charge carrier mobility of the corresponding devices. To address this challenge, we develop a novel low-dimensional (HtrzT)PbI₃ perovskite featuring a conjugated organic cation (1H-1,2,4-Triazole-3-thiol, HtrzT⁺) which matches well with the α-FAPbI₃ lattices in two-dimensional plane. Benefiting from the matched lattice between (HtrzT)PbI₃ and α-FAPbI₃, the anchored lattice enhances the Pb-I bond strength and effectively mitigates the inherent tensile strain of the α-FAPbI₃ crystal lattice. The X-ray detector based on (HtrzT)PbI₃(1.0)/FAPbI₃ device achieves a remarkable sensitivity up to 1.83 × 10⁵ μC Gy_air⁻¹ cm⁻², along with a low detection limit of 27.6 nGy_air s⁻¹, attributed to the release of residual stress, and the enhancement in carrier mobility-lifetime product. Furthermore, the detector exhibits outstanding stability under X-ray irradiation with tolerating doses equivalent to nearly 1.17 × 10⁶ chest imaging doses.

Highlights:
1 A lattice-anchoring strategy using low-dimensional perovskite addresses structural instability in α-formamidinium lead iodide (FAPbI₃) by matching crystal lattice, mitigating residual stress and tensile strain.
2 Enhanced Pb-I bonding strength and reduced lattice strain improve structural stability and carrier mobility-lifetime product, enabling efficient charge transport.
3 Optimized X-ray detectors achieve high sensitivity (1.83 × 10⁵ μC Gyair^–1 cm^–2), low detection limit (27.6 nGyair s^–1), and stable performance under prolonged irradiation.

Electric-Field-Driven Generative Nanoimprinting for Tilted Metasurface Nanostructures

Mon, 28 Jul 2025 00:00:00 +0000

Tilted metasurface nanostructures, with excellent physical properties and enormous application potential, pose an urgent need for manufacturing methods. Here, electric-field-driven generative-nanoimprinting technique is proposed. The electric field applied between the template and the substrate drives the contact, tilting, filling, and holding processes. By accurately controlling the introduced included angle between the flexible template and the substrate, tilted nanostructures with a controllable angle are imprinted onto the substrate, although they are vertical on the template. By flexibly adjusting the electric field intensity and the included angle, large-area uniform-tilted, gradient-tilted, and high-angle-tilted nanostructures are fabricated. In contrast to traditional replication, the morphology of the nanoimprinting structure is extended to customized control. This work provides a cost-effective, efficient, and versatile technology for the fabrication of various large-area tilted metasurface structures. As an illustration, a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays, demonstrating superior imaging quality.

Highlights:
1 The developed electric-field-driven generative-nanoimprinting technology enables direct fabrication of large-area tilted metasurface nanostructures with cost-efficiency and high-throughput advantages.
2 Real-time tuning of process parameters facilitates customized fabrication of various tilted metasurface nanostructures.
3 Integration of these custom-designed high-angle-tilted nanostructures into augmented reality displays achieves superior image quality.

A Hierarchical Short Microneedle-Cupping Dual-Amplified Patch Enables Accelerated, Uniform, Pain-Free Transdermal Delivery of Extracellular Vesicles

Wed, 23 Jul 2025 00:00:00 +0000

Microneedles (MNs) have been extensively investigated for transdermal delivery of large-sized drugs, including proteins, nucleic acids, and even extracellular vesicles (EVs). However, for their sufficient skin penetration, conventional MNs employ long needles (≥ 600 μm), leading to pain and skin irritation. Moreover, it is critical to stably apply MNs against complex skin surfaces for uniform nanoscale drug delivery. Herein, a dually amplified transdermal patch (MN@EV/SC) is developed as the stem cell-derived EV delivery platform by hierarchically integrating an octopus-inspired suction cup (SC) with short MNs (≤ 300 μm). While leveraging the suction effect to induce nanoscale deformation of the stratum corneum, MN@EV/SC minimizes skin damage and enhances the adhesion of MNs, allowing EV to penetrate deeper into the dermis. When MNs of various lengths are applied to mouse skin, the short MNs can elicit comparable corticosterone release to chemical adhesives, whereas long MNs induce a prompt stress response. MN@EV/SC can achieve a remarkable penetration depth (290 µm) for EV, compared to that of MN alone (111 µm). Consequently, MN@EV/SC facilitates the revitalization of fibroblasts and enhances collagen synthesis in middle-aged mice. Overall, MN@EV/SC exhibits the potential for skin regeneration by modulating the dermal microenvironment and ensuring patient comfort.

Highlights:
1 A bio-inspired dual-amplified patch (MN@EV/SC) was fabricated by integrating extracellular vesicle-loaded microneedles with a soft suction chamber for effective transdermal delivery.
2 The MN@EV/SC system achieved an exceptional penetration depth of 290 μm, while minimizing plasma corticosterone levels with short microneedles, ensuring patient comfort through pain-free application.
3 This system showed the potential for dermatological application by revitalizing dermal fibroblasts, and enhancing collagen synthesis through effective delivery of extracellular vesicles while preserving their biological functionality.

Metallic WO2-Promoted CoWO4/WO2 Heterojunction with Intercalation-Mediated Catalysis for Lithium–Sulfur Batteries

Mon, 21 Jul 2025 00:00:00 +0000

Lithium–sulfur (Li–S) batteries require efficient catalysts to accelerate polysulfide conversion and mitigate the shuttle effect. However, the rational design of catalysts remains challenging due to the lack of a systematic strategy that rationally optimizes electronic structures and mesoscale transport properties. In this work, we propose an autogenously transformed CoWO₄/WO₂ heterojunction catalyst, integrating a strong polysulfide-adsorbing intercalation catalyst with a metallic-phase promoter for enhanced activity. CoWO₄ effectively captures polysulfides, while the CoWO₄/WO₂ interface facilitates their S–S bond activation on heterogenous catalytic sites. Benefiting from its directional intercalation channels, CoWO₄ not only serves as a dynamic Li-ion reservoir but also provides continuous and direct pathways for rapid Li-ion transport. Such synergistic interactions across the heterojunction interfaces enhance the catalytic activity of the composite. As a result, the CoWO₄/WO₂ heterostructure demonstrates significantly enhanced catalytic performance, delivering a high capacity of 1262 mAh g⁻¹ at 0.1 C. Furthermore, its rate capability and high sulfur loading performance are markedly improved, surpassing the limitations of its single-component counterparts. This study provides new insights into the catalytic mechanisms governing Li–S chemistry and offers a promising strategy for the rational design of high-performance Li–S battery catalysts.

Highlights:
1 The CoWO₄/WO₂ heterojunction was successfully constructed through hydrothermal synthesis of precursors followed by autogenous transformation induced by hydrogen reduction.
2 The synergistic effect of CoWO₄ and WO₂ promotes the catalytic conversion of polysulfides and suppresses the shuttle effect.
3 The CoWO₄/WO₂ heterojunction demonstrates significantly enhanced catalytic performance, delivering a high capacity of 1262 mAh g⁻¹ at 0.1 C.

Ultrahigh Dielectric Permittivity of a Micron-Sized Hf0.5Zr0.5O2 Thin-Film Capacitor After Missing of a Mixed Tetragonal Phase

Wen Di Zhang, Bing Li, Wei Wei Wang, Xing Ya Wang, Yan Cheng, An Quan Jiang — Mon, 21 Jul 2025 00:00:00 +0000

Innovative use of HfO₂-based high-dielectric-permittivity materials could enable their integration into few-nanometre-scale devices for storing substantial quantities of electrical charges, which have received widespread applications in high-storage-density dynamic random access memory and energy-efficient complementary metal–oxide–semiconductor devices. During bipolar high electric-field cycling in numbers close to dielectric breakdown, the dielectric permittivity suddenly increases by 30 times after oxygen-vacancy ordering and ferroelectric-to-nonferroelectric phase transition of near-edge plasma-treated Hf_0.5Zr_0.5O₂ thin-film capacitors. Here we report a much higher dielectric permittivity of 1466 during downscaling of the capacitor into the diameter of 3.85 μm when the ferroelectricity suddenly disappears without high-field cycling. The stored charge density is as high as 183 μC cm⁻² at an operating voltage/time of 1.2 V/50 ns at cycle numbers of more than 10¹² without inducing dielectric breakdown. The study of synchrotron X-ray micro-diffraction patterns show missing of a mixed tetragonal phase. The image of electron energy loss spectroscopy shows the preferred oxygen-vacancy accumulation at the regions near top/bottom electrodes as well as grain boundaries. The ultrahigh dielectric-permittivity material enables high-density integration of extremely scaled logic and memory devices in the future.

Highlights:
1 Ferroelectric-to-nonferroelectric transition occurs in a micron-sized Hf_0.5Zr_0.5O₂ thin-film capacitor with the generation of a giant dielectric permittivity.
2 Synchrotron X-ray micro-diffraction patterns show missing of a mixed tetragonal phase in the capacitor.
3 The stored charge density of the capacitor is as high as 183 μC cm^-2 at an operating voltage/time of 1.2 V/50 ns at cycle numbers of more than 1012 without inducing dielectric breakdown.

A Promising Strategy for Solvent-Regulated Selective Hydrogenation of 5-Hydroxymethylfurfural over Porous Carbon-Supported Ni-ZnO Nanoparticles

Mon, 21 Jul 2025 00:00:00 +0000

Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization. Herein, we report porous carbon-supported Ni-ZnO nanoparticles catalyst (Ni-ZnO/AC) synthesized via low-temperature coprecipitation, exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural (HMF). A linear correlation is first observed between solvent polarity (E_T(30)) and product selectivity within both polar aprotic and protic solvent classes, suggesting that solvent properties play a vital role in directing reaction pathways. Among these, 1,4-dioxane (aprotic) favors the formation of 2,5-bis(hydroxymethyl)furan (BHMF) with 97.5% selectivity, while isopropanol (iPrOH, protic) promotes 2,5-dimethylfuran production with up to 99.5% selectivity. Mechanistic investigations further reveal that beyond polarity, proton-donating ability is critical in facilitating hydrodeoxygenation. iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal, lowering the activation barrier. In contrast, 1,4-dioxane, lacking hydrogen bond donors, stabilizes BHMF and hinders further conversion. Density functional theory calculations confirm a lower activation energy in iPrOH (0.60 eV) compared to 1,4-dioxane (1.07 eV). This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation, highlighting the decisive role of solvent-catalyst-substrate interactions.

Highlights:
1 A porous carbon-supported Ni-ZnO nanoparticles catalyst (Ni-ZnO/AC) was synthesized by low-temperature coprecipitation, demonstrating exceptional catalytic activity and stability.
2 Selective hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (97.5%) or 2,5-dimethylfuran (99.5%) is achieved over Ni-ZnO/AC catalyst by solvent-tuning.
3 Solvent-catalyst interaction jointly regulates hydrodeoxygenation behavior in HMF hydrogenation by modulating rate and pathway via a hydrogen shuttle mechanism.

A Synchronous Strategy to Zn-Iodine Battery by Polycationic Long-Chain Molecules

Da‑Qian Cai, Hengyue Xu, Tong Xue, Jin‑Lin Yang, Hong Jin Fan — Mon, 21 Jul 2025 00:00:00 +0000

Aqueous Zn-iodine batteries (ZIBs) face the formidable challenges towards practical implementation, including metal corrosion and rampant dendrite growth on the Zn anode side, and shuttle effect of polyiodide species from the cathode side. These challenges lead to poor cycle stability and severe self-discharge. From the fabrication and cost point of view, it is technologically more viable to deploy electrolyte engineering than electrode protection strategies. More importantly, a synchronous method for modulation of both cathode and anode is pivotal, which has been often neglected in prior studies. In this work, cationic poly(allylamine hydrochloride) (Pah⁺) is adopted as a low-cost dual-function electrolyte additive for ZIBs. We elaborate the synchronous effect by Pah⁺ in stabilizing Zn anode and immobilizing polyiodide anions. The fabricated Zn-iodine coin cell with Pah⁺ (ZnI₂ loading: 25 mg cm⁻²) stably cycles 1000 times at 1 C, and a single-layered 3 × 4 cm² pouch cell (N/P ratio ~ 1.5) with the same mass loading cycles over 300 times with insignificant capacity decay.

Highlights:
1 A long chain polycation (Pah⁺) is propos ed to simultaneously regulate Zn anode deposition , mitigate side reactions and stabilize iodine cathode chemistry.
2 The iodophilic and low diffusivity nature of Pah enables effective polyiodide immobilization, suppressing the shuttle effect and ensuring a stable redox environment.
3 The Zn iodine battery delivers high areal capacity (~4 mAh cm⁻² at 1 C) and excellent durability, with 95% capacity retained over 1000 cycles.

Recent Advances in Regulation Strategy and Catalytic Mechanism of Bi-Based Catalysts for CO2 Reduction Reaction

Fri, 08 Aug 2025 00:00:00 +0000

Using photoelectrocatalytic CO₂ reduction reaction (CO₂RR) to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises. Bismuth-based (Bi-based) catalysts have attracted widespread attention for CO₂RR due to their high catalytic activity, selectivity, excellent stability, and low cost. However, they still need to be further improved to meet the needs of industrial applications. This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories: (1) defect engineering, (2) atomic doping engineering, (3) organic framework engineering, (4) inorganic heterojunction engineering, (5) crystal face engineering, and (6) alloying and polarization engineering. Meanwhile, the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail, aiming to enable researchers to understand the structure–property relationship of the improved Bi-based catalysts fundamentally. Finally, the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO₂RR application field will also be featured from the perspectives of the (1) combination or synergy of multiple regulatory strategies, (2) revealing formation mechanism and realizing controllable synthesis, and (3) in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms. On the one hand, through the comparative analysis and mechanism explanation of the six major regulatory strategies, a multidimensional knowledge framework of the structure–activity relationship of Bi-based catalysts can be constructed for researchers, which not only deepens the atomic-level understanding of catalytic active sites, charge transport paths, and the adsorption behavior of intermediate products, but also provides theoretical guiding principles for the controllable design of new catalysts; on the other hand, the promising collaborative regulation strategies, controllable synthetic paths, and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts, conducive to facilitating the transition of photoelectrocatalytic CO₂RR technology from the laboratory routes to industrial application.

Highlights:
1 Six major types of structural regulation strategies of various Bi-based catalysts used in photoelectrocatalytic CO₂ reduction reaction (CO₂RR) in recent years are comprehensively summarized.
2 The corresponding catalytic mechanisms of each regulation strategy are discussed in detail, aiming to enable researchers to understand the structure–property relationship of the improved Bi-based catalysts fundamentally.
3 The challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO₂RR application field are featured from the perspectives of the combination of multiple regulatory strategies, revealing formation mechanism and realizing controllable synthesis, and in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.

On-Skin Epidermal Electronics for Next-Generation Health Management

Fri, 08 Aug 2025 00:00:00 +0000

Continuous monitoring of biosignals is essential for advancing early disease detection, personalized treatment, and health management. Flexible electronics, capable of accurately monitoring biosignals in daily life, have garnered considerable attention due to their softness, conformability, and biocompatibility. However, several challenges remain, including imperfect skin-device interfaces, limited breathability, and insufficient mechanoelectrical stability. On-skin epidermal electronics, distinguished by their excellent conformability, breathability, and mechanoelectrical robustness, offer a promising solution for high-fidelity, long-term health monitoring. These devices can seamlessly integrate with the human body, leading to transformative advancements in future personalized healthcare. This review provides a systematic examination of recent advancements in on-skin epidermal electronics, with particular emphasis on critical aspects including material science, structural design, desired properties, and practical applications. We explore various materials, considering their properties and the corresponding structural designs developed to construct high-performance epidermal electronics. We then discuss different approaches for achieving the desired device properties necessary for long-term health monitoring, including adhesiveness, breathability, and mechanoelectrical stability. Additionally, we summarize the diverse applications of these devices in monitoring biophysical and physiological signals. Finally, we address the challenges facing these devices and outline future prospects, offering insights into the ongoing development of on-skin epidermal electronics for long-term health monitoring.

Highlights:
1 This review comprehensively examines representative functional materials, analyzes their intrinsic properties, and illustrates how rational structural design and fabrication strategies can be employed to achieve high-performance epidermal electronics.
2 Three essential performance requirements for long-term, continuous health monitoring—adhesiveness, breathability, and mechanoelectrical stability—are emphasized, alongside effective strategies for their realization.
3 Current scientific challenges in this field are critically discussed, offering in-depth insights into the development of next-generation on-skin epidermal electronics aimed at transforming personalized healthcare.

Correction: Optimizing Exciton and Charge-Carrier Behavior in Thick-Film Organic Photovoltaics: A Comprehensive Review

Lu Wei, Yaxin Yang, Lingling Zhan, Shouchun Yin, Hongzheng Chen — Wed, 06 Aug 2025 00:00:00 +0000

Organic photovoltaics (OPVs) have achieved remarkable progress, with laboratory-scale single-junction devices now demonstrating power conversion efficiencies (PCEs) exceeding 20%. However, these efficiencies are highly dependent on the thickness of the photoactive layer, which is typically around 100 nm. This sensitivity poses a challenge for industrial-scale fabrication. Achieving high PCEs in thick-film OPVs is therefore essential. This review systematically examines recent advancements in thick-film OPVs, focusing on the fundamental mechanisms that lead to efficiency loss and strategies to enhance performance. We provide a comprehensive analysis spanning the complete photovoltaic process chain: from initial exciton generation and diffusion dynamics, through dissociation mechanisms, to subsequent charge-carrier transport, balance optimization, and final collection efficiency. Particular emphasis is placed on cutting-edge solutions in molecular engineering and device architecture optimization. By synthesizing these interdisciplinary approaches and investigating the potential contributions in stability, cost, and machine learning aspects, this work establishes comprehensive guidelines for designing high-performance OPVs devices with minimal thickness dependence, ultimately aiming to bridge the gap between laboratory achievements and industrial manufacturing requirements.

Highlights:
1 Research progress summary: Provides a systematic review of recent advancements in thick-film organic photovoltaics (OPVs) with a focus on molecular design and device engineering strategies.
2 Efficiency enhancement strategies: Explores the mechanisms limiting efficiency in thick-film devices, analyzes exciton and charge-carrier dynamics, and identifies effective approaches to improve device performance.
3 Industrialization contributions and outlook: Summarizes the potential contributions of thick-film OPVs to industrial applications and offers insights into future development directions (in stability, cost, and machine learning aspects).

Electrospun Nanofiber-Based Ceramic Aerogels: Synergistic Strategies for Design and Functionalization

Panpan Li, Xuan Zhang, Ying Li, Cunyi Zhao, Jianyong Yu, Yang Si — Wed, 06 Aug 2025 00:00:00 +0000

Ceramic aerogels (CAs) have emerged as a significant research frontier across various applications due to their lightweight, high porosity, and easily tunable structural characteristics. However, the intrinsic weak interactions among the constituent nanoparticles, coupled with the limited toughness of traditional CAs, make them susceptible to structural collapse or even catastrophic failure when exposed to complex mechanical external forces. Unlike 0D building units, 1D ceramic nanofibers (CNFs) possess a high aspect ratio and exceptional flexibility simultaneously, which are desirable building blocks for elastic CAs. This review presents the recent progress in electrospun ceramic nanofibrous aerogels (ECNFAs) that are constructed using ECNFs as building blocks, focusing on the various preparation methods and corresponding structural characteristics, strategies for optimizing mechanical performance, and a wide range of applications. The methods for preparing ECNFs and ECNFAs with diverse structures were initially explored, followed by the implementation of optimization strategies for enhancing ECNFAs, emphasizing the improvement of reinforcing the ECNFs, establishing the bonding effects between ECNFs, and designing the aggregate structures of the aerogels. Moreover, the applications of ECNFAs across various fields are also discussed. Finally, it highlights the existing challenges and potential opportunities for ECNFAs to achieve superior properties and realize promising prospects.

Highlights:
1 This review provides comprehensive fabrication methods for the manufacturing of electrospun ceramic nanofibrous aerogels and offers professional guidance for materials development in this field.
2 The optimization strategies for electrospun ceramic nanofibrous aerogels (ECNFAs)’ mechanical properties have been provided, highlighting multi-scale design from nano-building blocks to nanofiber aggregate structure design.
3 This review systematically introduces the diverse roles of ECNFAs in specific application scenarios and application-specific mechanisms and provides transformative solutions for advanced engineering applications.

Engineered Radiative Cooling Systems for Thermal-Regulating and Energy-Saving Applications

Tue, 05 Aug 2025 00:00:00 +0000

Radiative cooling systems (RCSs) possess the distinctive capability to dissipate heat energy via solar and thermal radiation, making them suitable for thermal regulation and energy conservation applications, essential for mitigating the energy crisis. A comprehensive review connecting the advancements in engineered radiative cooling systems (ERCSs), encompassing material and structural design as well as thermal and energy-related applications, is currently absent. Herein, this review begins with a concise summary of the essential concepts of ERCSs, followed by an introduction to engineered materials and structures, containing nature-inspired designs, chromatic materials, meta-structural configurations, and multilayered constructions. It subsequently encapsulates the primary applications, including thermal-regulating textiles and energy-saving devices. Next, it highlights the challenges of ERCSs, including maximized thermoregulatory effects, environmental adaptability, scalability and sustainability, and interdisciplinary integration. It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.

Highlights:
1 This review thoroughly encapsulates the contemporary advancements in radiative cooling systems, from materials to applications.
2 Comprehensive discussion of the fundamental concepts of radiative cooling systems, engineered materials, thermal-regulating textiles and energy-saving devices.
3 The review critically evaluates the obstacles confronting radiative cooling systems, offering insightful and forward-looking solutions to shape the future trajectory of the discipline.

MXene-Based Wearable Contact Lenses: Integrating Smart Technology into Vision Care

Arezoo Khosravi, Atefeh Zarepour, Ali Zarrabi, Siavash Iravani — Tue, 05 Aug 2025 00:00:00 +0000

MXene-based smart contact lenses demonstrate a cutting-edge advancement in wearable ophthalmic technology, combining real-time biosensing, therapeutic capabilities, and user comfort in a single platform. These devices take the advantage of the exceptional electrical conductivity, mechanical flexibility, and biocompatibility of two-dimensional MXenes to enable noninvasive, tear-based monitoring of key physiological markers such as intraocular pressure and glucose levels. Recent developments focus on the integration of transparent MXene films into the conventional lens materials, allowing multifunctional performance including photothermal therapy, antimicrobial and anti-inflammation protection, and dehydration resistance. These innovations offer promising strategies for ocular disease management and eye protection. In addition to their multifunctionality, improvements in MXene synthesis and device engineering have enhanced the stability, transparency, and wearability of these lenses. Despite these advances, challenges remain in long-term biostability, scalable production, and integration with wireless communication systems. This review summarizes the current progress, key challenges, and future directions of MXene-based smart contact lenses, highlighting their transformative potential in next-generation digital healthcare and ophthalmic care.

Highlights:
1 MXene-based smart contact lenses seamlessly combine real-time biosensing, therapeutic functions, and enhanced user comfort, revolutionizing ocular health monitoring and treatment.
2 The use of transparent MXene films enables features like photothermal therapy, antimicrobial protection, and dehydration resistance, significantly improving eye protection and disease management.
3 While stability, scalability, and wireless integration pose hurdles, ongoing advancements suggest these lenses hold tremendous potential for transforming digital healthcare and ophthalmic care.

Noninvasive On-Skin Biosensors for Monitoring Diabetes Mellitus

Ali Sedighi, Tianyu Kou, Hui Huang, Yi Li — Thu, 31 Jul 2025 00:00:00 +0000

Diabetes mellitus represents a major global health issue, driving the need for noninvasive alternatives to traditional blood glucose monitoring methods. Recent advancements in wearable technology have introduced skin-interfaced biosensors capable of analyzing sweat and skin biomarkers, providing innovative solutions for diabetes diagnosis and monitoring. This review comprehensively discusses the current developments in noninvasive wearable biosensors, emphasizing simultaneous detection of biochemical biomarkers (such as glucose, cortisol, lactate, branched-chain amino acids, and cytokines) and physiological signals (including heart rate, blood pressure, and sweat rate) for accurate, personalized diabetes management. We explore innovations in multimodal sensor design, materials science, biorecognition elements, and integration techniques, highlighting the importance of advanced data analytics, artificial intelligence-driven predictive algorithms, and closed-loop therapeutic systems. Additionally, the review addresses ongoing challenges in biomarker validation, sensor stability, user compliance, data privacy, and regulatory considerations. A holistic, multimodal approach enabled by these next-generation wearable biosensors holds significant potential for improving patient outcomes and facilitating proactive healthcare interventions in diabetes management.

Highlights:
1 A comprehensive and critical evaluation of recent advances in sweat-based biochemical and physiological biomarkers for noninvasive diabetes monitoring.
2 A novel emphasis on multimodal sensor integration—combining biochemical and physiological signals—to enhance accuracy, contextual awareness, and reliability in real-time diabetes management.
3 A forward-looking analysis of AI-driven biosensing systems, standardized protocols, and regulatory and ethical frameworks enabling autonomous, secure, and personalized diabetes care.

Advanced Design for High-Performance and AI Chips

Ying Cao, Yuejiao Chen, Xi Fan, Hong Fu, Bingang Xu — Tue, 29 Jul 2025 00:00:00 +0000

Recent years have witnessed transformative changes brought about by artificial intelligence (AI) techniques with billions of parameters for the realization of high accuracy, proposing high demand for the advanced and AI chip to solve these AI tasks efficiently and powerfully. Rapid progress has been made in the field of advanced chips recently, such as the development of photonic computing, the advancement of the quantum processors, the boost of the biomimetic chips, and so on. Designs tactics of the advanced chips can be conducted with elaborated consideration of materials, algorithms, models, architectures, and so on. Though a few reviews present the development of the chips from their unique aspects, reviews in the view of the latest design for advanced and AI chips are few. Here, the newest development is systematically reviewed in the field of advanced chips. First, background and mechanisms are summarized, and subsequently most important considerations for co-design of the software and hardware are illustrated. Next, strategies are summed up to obtain advanced and AI chips with high excellent performance by taking the important information processing steps into consideration, after which the design thought for the advanced chips in the future is proposed. Finally, some perspectives are put forward.

Highlights:
1 A comprehensive review focused on the recent advancement of the advanced and artificial intelligence (AI) chip is presented.
2 The design tactics for the enhanced and AI chips can be conducted from a diversity of aspects, with materials, circuit, architecture, and packaging technique taken into considerations, for the pursuit of multimodal data processing abilities, robust reconfigurability, high energy efficiency, and enhanced computing power.
3 A broad outlook on the future considerations of the advanced chip is put forward.

Optimizing Exciton and Charge-Carrier Behavior in Thick-Film Organic Photovoltaics: A Comprehensive Review

Lu Wei, Yaxin Yang, Lingling Zhan, Shouchun Yin, Hongzhen Chen — Wed, 23 Jul 2025 00:00:00 +0000

Tackling Challenges and Exploring Opportunities in Cathode Binder Innovation

Tingrun Lai, Li Wang, Zhibei Liu, Adnan Murad Bhayo, Yude Wang, Xiangming He — Mon, 21 Jul 2025 00:00:00 +0000

Long-life energy storage batteries are integral to energy storage systems and electric vehicles, with lithium-ion batteries (LIBs) currently being the preferred option for extended usage-life energy storage. To further extend the life span of LIBs, it is essential to intensify investments in battery design, manufacturing processes, and the advancement of ancillary materials. The pursuit of long durability introduces new challenges for battery energy density. The advent of electrode material offers effective support in enhancing the battery's long-duration performance. Often underestimated as part of the cathode composition, the binder plays a pivotal role in the longevity and electrochemical performance of the electrode. Maintaining the mechanical integrity of the electrode through judicious binder design is a fundamental requirement for achieving consistent long-life cycles and high energy density. This paper primarily concentrates on the commonly employed cathode systems in lithium-ion batteries, elucidates the significance of binders for both, discusses the application status, strengths, and weaknesses of novel binders, and ultimately puts forth corresponding optimization strategies. It underscores the critical function of binders in enhancing battery performance and advancing the sustainable development of lithium-ion batteries, aiming to offer fresh insights and perspectives for the design of high-performance LIBs.

Highlights:
1 Binders play a crucial role in the lifespan and performance of electrodes, but they are often overlooked. This paper mainly reviews the significance of the role of binders on cathode materials and the optimization strategies.
2 Focusing on LiFePO₄ and transition metal oxide cathode systems, this review systematically summarizes performance optimization strategies for novel binders tailored to the respective advantages and limitations of different cathodes.
3 The future development trend of cathode binders is analyzed, emphasizing the challenges and opportunities faced by binders in thermal safety and all-solid-state systems.

Monolithic Perovskite/Perovskite/Silicon Triple-Junction Solar Cells: Fundamentals, Progress, and Prospects

Leiping Duan, Xin Cui, Cheng Xu, Zhong Chen, Jianghui Zheng — Mon, 21 Jul 2025 00:00:00 +0000

Crystalline silicon (c-Si) solar cells, though dominating the photovoltaic market, are nearing their theoretical power conversion efficiencies (PCE) limit of 29.4%, necessitating the adoption of multi-junction technology to achieve higher performance. Among these, perovskite-on-silicon-based multi-junction solar cells have emerged as a promising alternative, where the perovskite offering tunable bandgaps, superior optoelectronic properties, and cost-effective manufacturing. Recent announced double-junction solar cells (PSDJSCs) have achieved the PCE of 34.85%, surpassing all other double-junction technologies. Encouragingly, the rapid advancements in PSDJSCs have spurred increased research interest in perovskite/perovskite/silicon triple-junction solar cells (PSTJSCs) in 2024. This triple-junction solar cell configuration demonstrates immense potential due to their optimum balance between achieving a high PCE limit and managing device complexity. This review provides a comprehensive analysis of PSTJSCs, covering fundamental principles, and technological milestones. Current challenges, including current mismatch, open-circuit voltage deficits, phase segregation, and stability issues, and their corresponding strategies are also discussed, alongside future directions to achieve long-term stability and high PCE. This work aims to advance the understanding of the development in PSTJSCs, paving the way for their practical implementation.

Highlights:
1 Perovskite/perovskite/silicon triple-junction solar cells (PSTJSCs) are emerging as a promising strategy to exceed the efficiency limits of traditional silicon solar cells.
2 This review systematically analyses the key principles, recent breakthroughs, and remaining challenges in PSTJSC development, including current mismatch, open-circuit voltage loss, phase segregation, and stability.
3 Strategies to address these issues and future directions toward achieving high efficiency and long-term operational stability are comprehensively discussed.

Thermally Drawn Flexible Fiber Sensors: Principles, Materials, Structures, and Applications

Mon, 21 Jul 2025 00:00:00 +0000

Flexible fiber sensors, with their excellent wearability and biocompatibility, are essential components of flexible electronics. However, traditional methods face challenges in fabricating low-cost, large-scale fiber sensors. In recent years, the thermal drawing process has rapidly advanced, offering a novel approach to flexible fiber sensors. Through the preform-to-fiber manufacturing technique, a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time. Examples include temperature, acoustic, mechanical, chemical, biological, optoelectronic, and multifunctional sensors, which operate on diverse sensing principles such as resistance, capacitance, piezoelectricity, triboelectricity, photoelectricity, and thermoelectricity. This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors. Finally, the future developments of thermally drawn fiber sensors are discussed.

Highlights:
1 The review briefly introduces the principle, material selection criteria, and development of the thermal drawing process.
2 Based on different stimuli, the review comprehensively summarizes the latest progress in thermally drawn temperature, acoustic, mechanical, chemical, biological, optoelectronic, and multifunctional sensors.
3 The review discusses the future development trends of thermally drawn fiber sensors in terms of material, structure, fabrication, function, and stability.

Mechanical Properties Analysis of Flexible Memristors for Neuromorphic Computing

Zhenqian Zhu, Jiheng Shui, Tianyu Wang, Jialin Meng — Mon, 21 Jul 2025 00:00:00 +0000

The advancement of flexible memristors has significantly promoted the development of wearable electronic for emerging neuromorphic computing applications. Inspired by in-memory computing architecture of human brain, flexible memristors exhibit great application potential in emulating artificial synapses for high-efficiency and low power consumption neuromorphic computing. This paper provides comprehensive overview of flexible memristors from perspectives of development history, material system, device structure, mechanical deformation method, device performance analysis, stress simulation during deformation, and neuromorphic computing applications. The recent advances in flexible electronics are summarized, including single device, device array and integration. The challenges and future perspectives of flexible memristor for neuromorphic computing are discussed deeply, paving the way for constructing wearable smart electronics and applications in large-scale neuromorphic computing and high-order intelligent robotics.

Highlights:
1 This review systematically summarizes materials system, development history, device structure, stress simulation and applications of flexible memristors.
2 This review highlights the critical influence of mechanical properties on flexible memristors, with particular emphasis on deformation parameters and finite element simulation.
3 The applications of future memristors in neuromorphic computing are deeply discussed for next-generation wearable electronics

High-Entropy Materials: A New Paradigm in the Design of Advanced Batteries

Yangmei Xin, Minmin Zhu, Haizhong Zhang, Xinghui Wang — Mon, 21 Jul 2025 00:00:00 +0000

High-entropy materials (HEMs) have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability, enhanced ionic conductivity, superior mechanical strength, and outstanding catalytic activity. These distinctive characteristics render HEMs highly suitable for various battery components, such as electrodes, electrolytes, and catalysts. This review systematically examines recent advances in the application of HEMs for energy storage, beginning with fundamental concepts, historical development, and key definitions. Three principal categories of HEMs, namely high-entropy alloys, high-entropy oxides, and high-entropy MXenes, are analyzed with a focus on electrochemical performance metrics such as specific capacity, energy density, cycling stability, and rate capability. The underlying mechanisms by which these materials enhance battery performance are elucidated in the discussion. Furthermore, the pivotal role of machine learning in accelerating the discovery and optimization of novel high-entropy battery materials is highlighted. The review concludes by outlining future research directions and potential breakthroughs in HEM-based battery technologies.

Highlights:
1 The development history, characteristics and applications of high entropy alloys, high entropy oxides and high entropy MXenes are reviewed.
2 High entropy materials as cathode, anode and electrolyte to improve batteries capacity, cycle life and cycle stability are introduced systematically.
3 The latest progresses of employing machine learning in high entropy battery materials are highlighted and discussed in details.