High Efficiency Solar Membranes Structurally Designed with 3D Core-2D Shell SiO2@Amino-Carbon Hybrid Advanced Composite for Facile Steam Generation

Helical Micropillar Processed by One-Step 3D Printing for Solar Thermal Conversion

Solar thermal utilization has broad applications in a variety of fields. Currently, maximizing the photo-thermal conversion efficiency remains a research hotspot in this field. The exquisite plant structures in nature have greatly inspired human structural design across many domains. In this work, inspired by the photosynthesis of helical grass, a HM type solar absorber made in graphene-based composite sheets is used for solar thermal conversion. The unique design promoted more effective solar energy into thermal energy through multiple reflections and scattering of solar photons. Notably, the Helical Micropillar (HM) is fabricated using a one-step projection 3D printing process based on a special 3D helical beam. As a result, the solar absorber's absorbance value can reach 0.83 in the 400-2500 nm range, and the surface temperature increased by ≈128.3% relative to the original temperature. The temperature rise rate of the solar absorber reached 22.4 °C min-1, demonstrating the significant potential of the HM in practical applications of solar thermal energy collection and utilization.

Hierarchical nanofibrous and recyclable membrane with unidirectional water-transport effect for efficient solar-driven interfacial evaporation

Solar-driven interfacial evaporation technology has attracted significant attention for water purification. However, design and fabrication of solar-driven evaporator with cost-effective, excellent capability and large-scale production remains challenging. In this study, inspired by plant transpiration, a tri-layered hierarchical nanofibrous photothermal membrane (HNPM) with a unidirectional water transport effect was designed and prepared via electrospinning for efficient solar-driven interfacial evaporation. The synergistic effect of the hierarchical hydrophilic-hydrophobic structure and the self-pumping effect endowed the HNPM with unidirectional water transport properties. The HNPM could unidirectionally drive water from the hydrophobic layer to the hydrophilic layer within 2.5 s and prevent reverse water penetration. With this unique property, the HNPM was coupled with a water supply component and thermal insulator to assemble a self-floating evaporator for water desalination. Under 1 sun illumination, the water evaporation rates of the designed evaporator with HNPM in pure water and dyed wastewater reached 1.44 and 1.78 kg·m-2·h-1, respectively. The evaporator could achieve evaporation of 11.04 kg·m-2 in 10 h under outdoor solar conditions. Moreover, the tri-layered HNPM exhibited outstanding flexibility and recyclability. Our bionic hydrophobic-to-hydrophilic structure endowed the solar-driven evaporator with capillary wicking and transpiration effects, which provides a rational design and optimization for efficient solar-driven applications.

Target immobilization on glass microfiber membranes as a label-free strategy for hit identification

The discovery of novel chemical entities targeting G protein-coupled receptors (GPCRs) is usually guided by their receptor affinity. However, traditional affinity assay methods and hit identification procedures are usually laborious and expensive. In this work, the type-2 vasopressin receptor (V2R) was chosen as a prototypical GPCR. Membrane fragments from cells highly expressing SNAP-V2R were immobilized on the surface of a glass microfiber (GMF) coated with O6-benzylguanine (BG). This was achieved by transferring the benzyl group of BG to the active site of the SNAP-tag through a nucleophilic substitution reaction. As a result, a biofilm called SNAP-V2R@GMF-BG was produced that showed good specificity and stability. The adsorption ratio for each V2R ligand treated with SNAP-V2R@GMF-BG was determined by HPLC and exhibited a good linear correlation with the Ki value determined by displacement assays. Furthermore, a Ki prediction assay was performed by comparing the data with that generated by a homogeneous time-resolved fluorescence (HTRF) assay. SNAP-V2R@GMF-BG was also used to screen hit compounds from natural products. After SNAP-V2R@GMF-BG was incubated with the total extract, the ligand that binds to V2R could be separated and subjected to LC‒MS analysis for identification. Baicalein was screened from Clerodendranthus spicatus and verified as a potential V2R antagonist. This V2R-immobilized GMF platform can help determine the affinity of V2R-binding hit compounds and screen the compounds efficiently and accurately.

Recycling Microplastics to Fabricate Anodes for Lithium-Ion Batteries: From Removal of Environmental Troubles via Electrocoagulation to Useful Resources

Electrocoagulation is an evolving technology for the abatement of a broad range of pollutants in wastewater owing to its flexibility, easy setup, and eco-friendly nature. Here, environment-friendly strategies for the separation, retreatment, and utilization of microplastics via electrocoagulation are investigated. The findings show that the flocs generated by forming Fe₃ O₄ on the surface of polyethylene (PE) particles are easily separated using a magnetic force with high efficiency of 98.4%. In the photodegradation of the obtained flocs, it is confirmed that Fe₃ O₄ shall be removed for the efficient generation of free radicals, leading to the highly efficient photolysis of PE. The removed Fe₃ O₄ can be recycled into iron-oxalate compounds, which can be used in battery applications. In addition, it is suggested that heat treatment of Fe₃ O₄ -PE flocs in an Ar atmosphere leads to forming Fe₃ O₄ core-carbon shell nanoparticles, which show excellent performance as anodes in lithium-ion batteries. The proposed composite exhibits an excellent capacity of 1123 mAh g^-1 at the current density of 0.5 A g^-1 after 600 cycles with a negative fading phenomenon. This study offers insight into a new paradigm of recyclable processes, from environmental issues such as microplastics to using energy materials.

Low cost, robust, environmentally friendly, wood supported 3D-hierarchical Cu3SnS4 for efficient solar powered steam generation

Solar steam generation has great potential in alleviating freshwater crises, particularly in regions with accessible seawater and abundant insolation. Inexpensive, efficient, and eco-friendly photothermal materials are desired to fabricate sunlight-driven evaporation devices. Here, we have designed an economical strategy to fabricate a high-performance wood-based solar steam generation device. In current study, 3D-hierarchical Cu₃SnS₄ has been loaded on wood substrates of variable sizes via an in-situ solvothermal method. Considering the water transportation capacity and thermal insulation property of wood, an enhanced light absorption was achieved by a uniform coating of Cu₃SnS₄ on the inside and outside of the 3D porous structure of the wood. Thanks for the synergistic effect of Cu₃SnS₄ and wood substrate, the obtained composite endorsed high-performance solar steam generation with a steam generation efficiency of 90% and an evaporation rate as high as 1.35 kg m^-2h^-1 under one sun.

Integrating a Self-Floating Janus TPC@CB Sponge for Efficient Solar-Driven Interfacial Water Evaporation

Solar-driven photothermal interfacial evaporation is considered as one of the most promising strategies in seawater desalination and wastewater treatment. In desalination, evaporation efficiency and salt resistance are regarded as two inter-constraint measures. Thus, it is still challenging to fabricate solar evaporators with both high evaporation efficiency and excellent salt resistance. In the present work, a self-floating Janus sponge composed of hydrophobic carbon black (CB) coating and hydrophilic porous thermoplastic polyurethane-carbon nanotube (TPC) nanofibrous substrate (TPC@CB) is fabricated via a simple electrospinning and gas templating expansion method. Attributing to the unique trilaminar functional architecture: the upper superhydrophobic solar-absorption coating, the intermediate ultrathin heat localization layer, and the lower cellular thermal insulation layer, the Janus TPC@CB sponge exhibits high evaporation efficiency (1.80 kg m^-2 h^-1 with an energy efficiency of 97.2% under 1.0 solar irradiation) and outstanding salt resistance ability. Moreover, zero liquid discharge in salt-containing wastewater treatment is realized using the Janus TPC@CB sponge as a solar-driven photothermal medium. This work provides a promising approach to seawater desalination and wastewater treatment.

How to Build a Microplastics-Free Environment: Strategies for Microplastics Degradation and Plastics Recycling

Microplastics are an emergent yet critical issue for the environment because of high degradation resistance and bioaccumulation. Unfortunately, the current technologies to remove, recycle, or degrade microplastics are insufficient for complete elimination. In addition, the fragmentation and degradation of mismanaged plastic wastes in environment have recently been identified as a significant source of microplastics. Thus, the developments of effective microplastics removal methods, as well as, plastics recycling strategies are crucial to build a microplastics-free environment. Herein, this review comprehensively summarizes the current technologies for eliminating microplastics from the environment and highlights two key aspects to achieve this goal: 1) Catalytic degradation of microplastics into environmentally friendly organics (carbon dioxide and water); 2) catalytic recycling and upcycling plastic wastes into monomers, fuels, and valorized chemicals. The mechanisms, catalysts, feasibility, and challenges of these methods are also discussed. Novel catalytic methods such as, photocatalysis, advanced oxidation process, and biotechnology are promising and eco-friendly candidates to transform microplastics and plastic wastes into environmentally benign and valuable products. In the future, more effort is encouraged to develop eco-friendly methods for the catalytic conversion of plastics into valuable products with high efficiency, high product selectivity, and low cost under mild conditions.

Polypyrrole-Dopamine Nanofiber Light-Trapping Coating for Efficient Solar Vapor Generation

Solar vapor generation (SVG) typically uses a solar absorbing material at the water-air interface to convert solar energy into heat for evaporation. However, the intrinsic solar absorption of the material determines the upper limit of the solar energy capture. By designing a light-trapping surface structure with open pores and channels, we can break this limit and further improve the absorption by enabling multiple reflections within the surface. Polypyrrole (PPy) is emerging as a promising solar thermal material. In this work, we propose an ultrasonic spray coating method to obtain a nanofiber light-trapping coating by copolymerization with dopamine (DA), which can be directly synthesized at room temperature rapidly (30 min). Due to its excellent wettability, this coating can transport water and can be directly coated on the thermal insulating layer, not requiring an additional water transport layer. This nanoscale coating significantly improves solar absorption at different incident angles across the full solar spectrum, achieving the highest solar-to-thermal conversion efficiency of 95.8% at 1.385 kg·m^-2·h^-1 under 1 sun. When applied on salt water, this solar evaporator achieves self-cleaning in the absence of solar irradiation. Moreover, the surface structure can be further tuned into granular/plane-fibrous/plane-granular structures by using different oxidants or surfactants, and their formation mechanisms are also proposed. This PPy-DA nanofiber coating shows great potential for SVG and other applications based on a PPy material, especially for those requiring a certain surface morphology.

Synthesis of a Co-Sn Alloy-Deposited PTFE Film for Enhanced Solar-Driven Water Evaporation via a Super-Absorbent Polymer-Based "Water Pump" Design

Solar-driven water evaporation is a promising solution to water pollution, the energy crisis, and water shortages. However, the approach in which the photothermal film is in direct contact with bulk water for water evaporation may lead to a large amount of heat loss, thereby reducing the light-to-heat conversion efficiency (η) of the photothermal film. Here, a highly efficient solar-driven water evaporation system was developed using a Co-Sn alloy-deposited Teflon (PTFE) film (Co-Sn alloy@PTFE) and super-absorbent polymers (SAPs) supported with a floating foam substrate. The Co-Sn alloy with full-spectrum (200-2500 nm) absorption characteristics is devoted to high light-to-heat conversion, while the porous PTFE with high mechanical performance can support the Co-Sn alloy. We used density functional theory to prove that the Co-Sn alloy had a strong adhesive force with PTFE without surfactants due to the high adsorption energy between the (101) crystal plane of the Co-Sn alloy and the hydroxyl group on the PTFE film. Importantly, via the SAP-based "water pump" design, we improved the η of the Co-Sn alloy@PTFE film to 89%, mainly because the SAP not only effectively performed water transportation but also markedly reduced the heat loss of the Co-Sn alloy@PTFE film. Our work highlights the strong potential of Co-Sn alloy@PTFE-based light-to-heat conversion systems for realizing highly effective solar energy-driven water evaporation.

Self-Assembled Hydrophobic/Hydrophilic Porphyrin-Ti3C2Tx MXene Janus Membrane for Dual-Functional Enabled Photothermal Desalination

Photothermal desalination is a promising approach for seawater purification by harvesting solar energy. Titanium carbide (Ti₃C₂T_x MXene) membranes have been regarded as potential materials for photothermal desalination by virtue of their excellent light-to-heat conversion. However, achieving a well-balanced synergy between high evaporation rate and good salt resistance remains a significant challenge due to their limited solar absorption and inferior stability. Herein, we report a self-assembled flexible porphyrin-Ti₃C₂T_x MXene Janus membrane (Janus PMX membrane) for dual-functional enabled photothermal desalination. The self-assembly of porphyrin on MXene not only effectively creates a favorable hydrophobic surface but also simultaneously enables efficient solar utilization. The significant interactions and charge redistribution between MXene and porphyrin lead to a stable hydrophobic/hydrophilic Janus structure with synergistically enhanced photothermal conversion. As a result, the Janus PMX membrane demonstrates highly efficient water pumping, heat localization, vapor generation, and salt resistance during photothermal desalination. This work presents an effective and facile strategy toward advancing a well-performing MXene membrane for efficient seawater desalination.