Qi Zhao

The development of photocatalytic membranes using electrospinning technology has significantly advanced their practical applications. However, current photocatalytic membranes are encountering the issues of poor mechanical property in non‐elastic fiber and low charge carrier separation efficiency in non‐conductive polymer. Through improving thermoplastic polyurethane (TPU) precursor dissolution and adding conductive polyaniline (PANI) respectively before and after electrospinning, TiO₂‐based elastic conductive (EC) TPU membranes with higher mechanical strength and photocatalytic performance are created, compared to traditional inelastic non‐conductive (IN) membrane, even to inelastic conductive (IC) membrane. The nanofibers in the TiO₂ EC membrane have a relatively rough surface structure, which exposes more catalytic sites. Ultraviolet photoelectron spectrum (UPS) test results show that the work function (φ) of TiO₂ in EC membrane becomes lower than in IN and IC membranes, leading to the strongest electron transfer potential for photocatalytic reactions. For the photocatalytic degradation of Methyl Orange (MO), the TiO₂ EC membrane demonstrates the best degradation rate of 49.43% over 3 days among three samples. These findings suggest that the TiO₂ EC membrane is promising for in‐site micropollutant water treatment in the real‐world.

The interfacial solar vapor generation (ISVG) process is an environmentally friendly approach that utilizes solar to produce steam, which can solve the water shortage. Despite many previous research studies, claims beyond the theoretical limit have risen due to limitations in the efficiency of converting solar to vapor and the rate of solar evaporation, which are still being debated. Energy losses remain even under ideal conditions, which means that the efficiency of the system will never be ≥100%. This review primarily analyzes the theoretical values of evaporation rate and energy efficiency in the ISVG process. Utilizing a theoretical formula for energy distribution, the factors contributing to the current exceedance of conversion efficiency and evaporation rate are scrutinized. By examining various strategies, such as the reduction of vaporization enthalpy for photothermal materials and the utilization of environmental energy for evaporation, these studies seek to enhance evaporation efficiencies, but they ignore the problem of the theoretical limit of evaporation. Therefore, this review emphasizes misconceptions about efficiencies beyond theoretical limits and aims to guide researchers to provide plausible explanations for such breakthroughs under specific conditions, alongside established reference conditions. Ultimately, this study lays a solid theoretical foundation for practical solar water purification.

With the serious pollution of water resources in the process of social development, green and environmentally friendly photocatalytic technology has gradually attracted widespread attention. Though photocatalytic theory and technology are relatively mature, the current research is mainly focused on powders and less on the photocatalytic membranes, and few real practical cases of photocatalysis are studied. To summarize and update these advanced studies, this paper introduces the latest progress in photocatalytic membranes including discussing the differences of photocatalytic mechanism between free and fixed photocatalytic systems and the design philosophy of photocatalytic membranes. At the same time, some common fabrication methods, including in situ growth, coating, spinning, casting, and foaming methods are analyzed. Besides, the photocatalytic performances of different photocatalytic membranes in the actual environment and their use conditions are explored. Finally, a critical view of future trends is included. The explanation of the photocatalytic mechanism, large‐scale production, and the practicality of photocatalytic products are all problems that need to be solved in the future.

Solar-driven interfacial evaporation and purification is a promising solar energy conversion technology to produce clean water or solve water scarcity. Although wood-based photothermal materials have attracted particular interest in solar water purification and desalination due to their rapid water supply and great heat localization, challenges exist given their complicated processing methods and relatively poor stability. Herein, we propose a facile approach for fabricating a bilayered wood-poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (wood-PEDOT:PSS) hydrogel interfacial evaporator by direct drop-casting and dry-annealing. Benefiting from the unique combined merits of the wood-PEDOT:PSS hydrogel evaporator, i.e., excellent light absorption (~99.9%) and efficient photothermal conversion of nanofibrous PEDOT:PSS and the strong hydrophilicity and fast water transport from wood, the as-fabricated bilayered wood-PEDOT:PSS hydrogel evaporator demonstrates a remarkably high evaporation rate (~1.47 kg m⁻² h⁻¹) and high energy efficiency (~75.76%) at 1 kW m⁻². We further demonstrate the practical applications of such an evaporator for sewage purification and desalination, showing outstanding performance stability and partial salt barrier capability against a continuous 10-day test in simulated seawater and an ultrahigh ion removal rate of 99.9% for metal ion-containing sewage. The design and fabrication of such novel, efficient wood-based interfacial evaporators pave the way for large-scale applications in solar water purification.

Four novel isoindigo–thiophene D–A–D–type precursors are synthesized by Stille coupling and electrosynthesized to yield corresponding hybrid polymers with favorable electrochemical and electrochromic performances. Intrinsic structure–property relationships of precursors and corresponding polymers, including surface morphology, band gaps, electrochemical properties, and electrochromic behaviors, are systematically investigated. The resultant isoindigo–thiophene D–A–D–type polymer combines the merits of isoindigo and polythiophene, including the excellent stability of isoindigo–based polymers and the extraordinary electrochromic stability of polythiophene. The low onset oxidation potential of precursors ranges from 1.10 to 1.15 V vs. Ag/AgCl, contributing to the electrodeposition of high–quality polymer films. Further kinetic studies illustrate that isoindigo–thiophene D–A–D–type polymers possess favorable electrochromic performances, including high optical contrast (53%, 1000 nm), fast switching time (0.8 s), and high coloration efficiency (124 cm² C⁻¹). These features of isoindigo–thiophene D–A–D–type conjugated polymers could provide a possibility for rational design and application as electrochromic materials.

Flexible strain sensor as a measurement tool plays a significant role in agricultural development by long-term stable monitoring of the dynamic progress of plant growth. However, existing strain sensors still suffer from severe drawbacks, such as large hysteresis, insufficient fatigue resistance, and inferior stability, limiting their broad applications in the long-term monitoring of plant growth. Herein, we fabricate a novel conductive hydrogel strain sensor which is achieved through uniformly dispersing the conductive activated charcoal (AC) in high-viscosity polyvinyl alcohol (PVA) solution forming a continuous conductive network and simple preparation by freezing-thawing. The as-prepared strain sensor demonstrates low hysteresis (−2), and long-term sensing stability upon mechanical cycling. We further exhibit the integration and application of PVA-AC strain sensor to monitor the growth of plants for 14 days. This work may offer an effective strategy for monitoring plant growth with conductive hydrogel strain sensor, facilitating the advancement of agriculture.