Conformal Microfluidic-Blow-Spun 3D Photothermal Catalytic Spherical Evaporator for Omnidirectional Enhanced Solar Steam Generation and CO2 Reduction

Portable water collection bag based on solar-driven interfacial evaporation

Convenient and portable, sustained provision of safe drinking water is crucial for wilderness survival. In this study, a portable water collection bag utilising solar-driven interface evaporation technology has been developed. The water collection bag includes a plastic film, CB-PS microsphere evaporator, and a small vial. By placing on the water surface, the CB-PS microspheres float and absorb sunlight to quickly evaporate the surrounding water. The plastic film and vial make it easy and fast to collect clean and safe drinking water. The device boasts an impressive evaporation rate of 1.64 kg·m⁻²·h⁻¹ under 1 sun illumination. Moreover, the portable water collection bag can withstand harsh acidic and alkaline conditions, efficiently removing organic contaminants from wilderness water sources to meet drinking water standards. Importantly, it is designed for repeated use without any water evaporation rate decreasing. The portable water collection bag also exhibits strong resistance to salt, making it suitable for applications in desalinating seawater into freshwater.

Bioinspired Pyramidal Array Photothermal Structure for Highly Efficient Water Evaporation under Omnidirectional Illumination

Solar-driven interfacial evaporation is regarded as a green and sustainable strategy to address the global freshwater crisis. Nevertheless, it remains challenging to develop a photothermal structure with highly efficient evaporation under omnidirectional illumination. Herein, a three-dimensional multiscale pyramidal array photothermal structure (PAPS) was developed from the inspiration of durian skin. It consisted of macroscale three-dimensional pyramidal array structures to enhance light absorption and increase the evaporation area, microscale porous structures to ensure continuous water transport and facilitate vapor diffusion, and nanoscale protrusion structures with hybrid photothermal materials of CuxO/C to enhance light trapping and photothermal conversion efficiency. It was fabricated in a porous foam matrix by a facile milling process. The PAPS induced an evaporation rate of 2.08 kg/m2h under one sun illumination under direct light conditions, which was 24% higher than that of a planar photothermal structure. The PAPS maintained fairly good evaporation performance under inclined light conditions, i.e., the evaporation rate of the PAPS was 1.72 kg/m2h at 45° inclined light angle. It only decreased by 17% compared to the direct sunlight conditions, which was much smaller than the 29% decrease of the planar photothermal structure. Additionally, the PAPS present a large evaporation rate of 6.29 kg/m2h under one sun illumination in air convection conditions with a wind speed of 3 m/s. This work provided a high-performance pyramidal array photothermal structure for highly efficient water evaporation under omnidirectional illumination, which provides potential opportunities for stable solar desalination and freshwater supply in complex and variable environments.

Design of MOF-Based Solar Evaporators With Hierarchical Microporous/Nanobridged/Nanogranular Structures for Rapid Interfacial Solar Evaporation and Fresh Water Collection

Interfacial solar evaporation (ISE) holds considerable promise to solve fresh water shortage, but it is challenging to achieve high evaporation rate (Reva) and fresh water yield in close system. Here, we report design and preparation of MOF-based solar evaporators with hierarchical microporous/nanobridged/nanogranular structures for rapid ISE and fresh water collection in close system. The evaporators are fabricated by growing silicone nanofilaments with variable length as nanobridges on a microporous silicone sponge followed by grafting with polydopamine nanoparticles and Cu-MOF nanocrystals. Integration of the unique structure and excellent photothermal composites endows the evaporators with high Reva of 3.5-20 wt % brines (3.60-2.90 kg m-2 h-1 in open system and 2.38-1.44 kg m-2 h-1 in close system) under simulated 1 sun, high Reva under natural sunlight, excellent salt resistance and high fresh water yield, which surpass most state-of-the-art evaporators. Moreover, when combined with a superhydrophilic cover, the evaporators show much higher average Reva of real seawater, remarkable fresh water yield and excellent long-term stability over one month continuous ISE under natural sunlight. The findings here will promote the development of advanced evaporators via microstructure engineering and their real-world ISE applications.

One-Pot Fabrication of Copper-Doped WO3·H2O Opto-Functional Layered Device using Submerged Photosynthesis of Crystallites

This study introduces a one-pot, submerged photosynthesis of crystallites (SPsC) method for fabricating monohydrate tungstic acid (WO3·H2O) nanoplates directly integrated onto a stainless steel mesh, offering a simplified production and enhanced device stability for optical functional applications. The fabricated devices demonstrate exceptional broadband light absorption across the ultraviolet (UV), visible (Vis), and near-infrared (NIR) ranges. Notably, 1% Cu doping significantly boosts the NIR absorption, yielding a high solar utilization efficiency of 81.40%. In solar water evaporation experiments, the devices exhibit a maximum temperature increase of 13 °C under 1-Sun (100 mW/cm2) illumination, achieving an energy conversion efficiency of 32.5%. Moreover, electrochemical characterization reveals light-induced conductivity changes and enhanced current density, suggesting potential applications in rectifying devices. This versatile and environmentally conscious SPsC fabrication method holds promise for the sustainable development of diverse nanodevices.

An in-depth study of integrating cascaded photocatalytic H2O2 generation and activation with solar-driven interfacial evaporation for in-situ organic contaminant remediation

Integrating cascaded photocatalytic H2O2 generation and subsequent activation of H2O2 (into ·OH radicals) with solar-driven interfacial evaporation techniques offers an effective and sustainable approach for in-situ treating water contaminated with organic substances. Unlike traditional water-dispersed catalysts, the interfacial evaporation approach presents unique challenges in photocatalytic reactions. We explored these dynamics using an AgI/PPy/MF interfacial photothermal set, achieving H2O2 production efficiency (approximately 1.53 mM/g/h) - three times higher than submerged counterparts. This efficiency is attributed to exceptional solar light absorption (about 95 %), a significant surface photothermal effect (raising temperatures by approximately 36 °C), and enhanced oxygen availability (38 times more than in water), all characteristic of the interfacial system. The in-situ activation of H2O2 into ·OH notably improves the degradation of organic pollutants, achieving up to 99 % removal efficiency. This comprehensive analysis highlights the potential of combining photocatalytic H2O2 processes with interfacial evaporation for efficiently purifying organically polluted water.

Recent Advances in High-Rate Solar-Driven Interfacial Evaporation

Recent advances in solar-driven interfacial evaporation (SDIE) have led to high evaporation rates that open promising avenues for practical utilization in freshwater production and industrial application for pollutant and nutrient concentration, and resource recovery. Breakthroughs in overcoming the theoretical limitation of 2D interfacial evaporation have allowed for developing systems with high evaporation rates. This study presents a comprehensive review of various evaporator designs that have achieved pure evaporation rates beyond 4 kg m-2 h-1, including structural and material designs allowing for rapid evaporation, passive 3D designs, and systems coupled with alternative energy sources of wind and joule heating. The operational mechanisms for each design are outlined together with discussion on the current benefits and areas for improvement. The overarching challenges encountered by SDIE concerning the feasibility of direct integration into contemporary practical settings are assessed, and issues relating to sustaining elevated evaporation rates under diverse environmental conditions are addressed.

Chitin Nanofibers Enable the Colloidal Dispersion of Carbon Nanomaterials in Aqueous Phase and Hybrid Material Coassembly

Chitin nanofibrils (ChNF) sourced from discarded marine biomass are shown as effective stabilizers of carbon nanomaterials in aqueous media. Such stabilization is evaluated for carbon nanotubes (CNT) considering spatial and temporal perspectives by using experimental (small-angle X-ray scattering, among others) and theoretical (atomistic simulation) approaches. We reveal that the coassembly of ChNF and CNT is governed by hydrophobic interactions, while electrostatic repulsion drives the colloidal stabilization of the hybrid ChNF/CNT system. Related effects are found to be transferable to multiwalled carbon nanotubes and graphene nanosheets. The observations explain the functionality of hybrid membranes obtained by aqueous phase processing, which benefit from an excellent areal mass distribution (correlated to piezoresistivity), also contributing to high electromechanical performance. The water resistance and flexibility of the ChNF/CNT membranes (along with its tensile strength at break of 190 MPa, conductivity of up to 426 S/cm, and piezoresistivity and light absorption properties) are conveniently combined in a device demonstration, a sunlight water evaporator. The latter is shown to present a high evaporation rate (as high as 1.425 kg water m-2 h-1 under one sun illumination) and recyclability.

Advancements in Nanoenabled Membrane Distillation for a Sustainable Water-Energy-Environment Nexus

The emergence of nano innovations in membrane distillation (MD) has garnered increasing scientific interest. This enables the exploration of state-of-the-art nano-enabled MD membranes with desirable properties, which significantly improve the efficiency and reliability of the MD process and open up opportunities for achieving a sustainable water-energy-environment (WEE) nexus. This comprehensive review provides broad coverage and in-depth analysis of recent innovations in nano-enabled MD membranes, focusing on their role in achieving desirable properties, such as strong liquid-repellence, high resistance to scaling, fouling, and wetting, as well as efficient self-heating and self-cleaning functionalities. The recent developments in nano-enhanced photothermal-catalytic applications for water-energy co-generation within a single MD system are also discussed. Furthermore, the bottlenecks are identified that impede the scale-up of nanoenhanced MD membranes and a future roadmap is proposed for their sustainable commercialiation. This holistic overview is expected to inspire future research and development efforts to fully harness the potential of nano-enabled MD membranes to achieve sustainable integration of water, energy, and the environment.

Iron diselenide/carbon black loaded mushroom-shaped evaporator for efficiently continuous solar-driven desalination

Solar-driven desalination is an environmentally sustainable method to alleviate the problems of freshwater scarcity and the energy crisis. However, how to improve the synergy between the photothermal material and the evaporator to achieve high photothermal conversion efficiency simultaneously, excellent thermal management system and good salt resistance remains a challenge. Here, a mushroom-shaped solar evaporation device is designed and fabricated with iron diselenide/carbon black (FeSe2/CB) coated cellulose acetate (CA) film as mushroom surface and cotton swab as mushroom handle, which presented high solar-driven evaporation and excellent salt resistance. Thanks to the unique photothermal effect and the synergistic effect, the FeSe2/CB composites enabled a promising photothermal conversion efficiency of up to 65.8 °C after 180 s. The mushroom-shaped evaporation device effectively overcomes water transport and steam spillage channel blockage caused by salt crystallization through its unique vertical transport water channels and conical air-water interface. When exposed to real sunlight, the solar evaporation rate of the steam generation structure reached as high as 2.03 kg m-2 h-1, which is more than 13 times higher than natural evaporation. This study offered new insights into the higher solar-driven evaporation rate and salt-blocking resistance of the FeSe2/CB mushroom-shaped solar evaporation device for solar-powered water production.

Making Nanofiber Membrane Stand on End to Construct Vertically Interfacial Evaporators for Efficient Solar Evaporation, Omnidirectional Solar Absorption, and Ultrahigh-Salinity Brine Desalination

Solar-driven interfacial desalination is widely considered to be a promising technology to address the global water crisis. This study proposes a novel electrospun nanofiber-based all-in-one vertically interfacial solar evaporator endowed with a high steam generation rate, steady omnidirectional evaporation, and enduring ultrahigh-salinity brine desalination. In particular, the electrospun nanofiber is collected into the tubular structure, followed by spraying with a dense crosslinked poly(vinyl alcohol) film, which renders them sufficiently strong for the preparation of a vertically array evaporator. The integrated evaporator made an individual capillary as a unit to form multiple thermal localization interfaces and steam dissipation channels, realizing zone heating of water. Thus a high steam generation rate exceeding 4.0 kg m-2 h-1 in pure water is demonstrated even under omnidirectional sunlight, and outperforms existing evaporators. Moreover, salt ions in the photothermal layer can be effectively transported to the water in capillaries and subsequently exchanged with the bulk water due to the strong action of capillary force, which ensures an ultrahigh desalination rate (≈12.5 kg m-2 h-1 under 3 sun) in 25 wt% concentration brine over 300 min. As such, this work provides a meaningful roadmap for the development of state-of-the-art solar-driven interfacial desalination.

Interfacial Solar Evaporation: From Fundamental Research to Applications

In the last decade, interfacial solar steam generation (ISSG), powered by natural sunlight garnered significant attention due to its great potential for low-cost and environmentally friendly clean water production in alignment with the global decarbonization efforts. This review aims to share the knowledge and engage with a broader readership about the current progress of ISSG technology and the facing challenges to promote further advancements toward practical applications. The first part of this review assesses the current strategies for enhancing the energy efficiency of ISSG systems, including optimizing light absorption, reducing energy losses, harvesting additional energy, and lowering evaporation enthalpy. Subsequently, the current challenges faced by ISSG technologies, notably salt accumulation and bio-fouling issues in practical applications, are elucidated and contemporary methods are discussed to overcome these challenges. In the end, potential applications of ISSG, ranging from initial seawater desalination and industrial wastewater purification to power generation, sterilization, soil remediation, and innovative concept of solar sea farm, are introduced, highlighting the promising potential of ISSG technology in contributing to sustainable and environmentally conscious practices. Based on the review and in-depth understanding of these aspects, the future research focuses are proposed to address potential issues in both fundamental research and practical applications.

Super-hydrophilic LaCoO3/g-C3N4 nanocomposite coated beauty sponge for solar-driven seawater desalination with simultaneous volatile organic compound removal

Interfacial solar steam generation (ISSG) is emerging as a promising, environment-friendly solution for fulfilling freshwater and energy demands. However, a critical challenge for ISSG lies in the presence of harmful volatile organic compounds (VOCs) in the feedwater which are co-evaporated with water, leading to more enriched concentration in condensed water. Herein, lanthanum cobaltate-graphitic carbon nitride (LaCoO3/g-C3N4, LCO/g-CN) nanocomposite decorated beauty sponge (LCO/g-CN@BS) is proposed as an efficient photothermal/photocatalytic material for solar-driven seawater desalination and simultaneous VOC degradation. The hydrophobic surface of the beauty sponge after LCO/g-CN coating becomes super-hydrophilic, ensuring sufficient water supply and our LCO/g-CN@BS delivers an evaporation rate of 1.94 kg m-2 h-1 under 1 sun irradiation. This LCO/g-CN@BS shows excellent seawater desalination capacity with a self-cleaning ability when employed for saltwater purification for a salt (NaCl) concentration as high as 15 wt%. Moreover, fast photocarrier transfer between LCO and g-CN leads to enhanced photocatalytic degradation of over 90% of phenol simultaneously, which is about 60% for only an LCO-based beauty sponge. This work presents a promising approach to combining novel nanocomposites with microporous structures for efficient solar desalination, offering simultaneous VOC degradation.

Reusable Floating Spherical Hydrogel Evaporator for Solar Desalination with Salt Mitigation and Contaminant Elimination

The generation of clean and drinkable fresh water from seawater and contaminated water holds great potential to mitigate water scarcity. Herein, a floating spherical hydrogel evaporator (SHE) is designed to achieve sunlight-driven desalination, self-salt cleaning, and removal of environmental contaminants. The spherical lightweight polystyrene is coated with a porous carbon-embedded sodium alginate/PVA/CMC photothermal hydrogel to generate a spherical hydrogel evaporator (SHE) that floats naturally. The SHE is very sensitive to the weight imbalance (500 mg) and can respond quickly to the accumulation of salt by rotation to the fresh evaporation surface, realizing excellent antisalt fouling performance. Remarkably, with energy localization by porous carbon, the spherical floating evaporator achieved a high evaporation rate of 2.65 kg m-2 h-1 with an evaporation efficiency of 98%. At the same time, SHE is also capable of adsorbing both organic contaminants and heavy metal ions through functional groups of the hydrogel, attaining 99% removal efficiency. Overall, this low-cost spherical floating evaporator may offer solution for eco-friendly and sustainable production of fresh water on a large scale.

A scalable and anti-fouling silver-nickel/cellulose paper with synergy photothermal effect for efficient solar distillation

Solar interfacial evaporation is one of the most efficient and environmentally-friendly clean freshwater production technologies. Plasma metal nanoparticles are excellent optical absorption materials, but their high cost and inherent resonance narrow bandwidth absorption limit their application. In this work, commercial cellulose papers are used as substrates to synthesize Ag-Ni/cellulose paper by the seed-mediated method. The Ag-Ni/cellulose paper exhibits high light absorption at the full wavelength (200-2500 nm) resulting from the synergistic effect of localized surface plasmon resonance (LSPR) of Ag NPs and the interband transitions (IBTs) of Ni. Under one-sun irradiation (1 kW m-2), the energy utilization efficiency of Ag-Ni/cellulose paper is as high as 93.8%, and the water evaporation rate is 1.87 kg m-2 h-1. Diffusion inhibition experiment results show that the Ag-Ni/cellulose paper exhibits excellent antibacterial performance, and the antibacterial performance is highly related with Ag NPs content. These provide new opportunities for commercial production of competitive cost, green, and portable solar evaporators for different application sceneries.

Non-Lignin Constructing the Gas-Solid Interface for Enhancing the Photothermal Catalytic Water Vapor Splitting

The progress of solar-driven water-splitting technology has been impeded by the limited light response capability of semiconductor materials. Despite attempts to leverage nearly 50% of infrared radiation for photothermal synergy and catalytic reaction enhancement, heat loss during liquid phase reactions results in low energy conversion efficiency. Here, the photothermally driven catalytic water-splitting system, which designs K-SrTiO3 -loaded TiN silica wool at the water-air interface. Photocatalytic tests and density functional theory calculations demonstrate that the thermal effect transforms liquid water into water vapor, thereby reducing the reaction free energy of catalysts and improving the transmission rate of catalytic products. Hence, the hydrogen evolution rate reaches 275.46 mmol m-2  h-1 , and the solar-to-hydrogen (STH) efficiency is 1.81% under 1 sun irradiation in this gas-solid system, which is more than twice that of liquid water splitting. This novel photothermal catalytic pathway, which involves a coupled reaction of water evaporation and water splitting, is anticipated to broaden the utilization range of the solar spectrum and significantly enhance the conversion efficiency of STH.

Advances in photothermal regulation strategies: from efficient solar heating to daytime passive cooling

Photothermal regulation concerning solar harvesting and repelling has recently attracted significant interest due to the fast-growing research focus in the areas of solar heating for evaporation, photocatalysis, motion, and electricity generation, as well as passive cooling for cooling textiles and smart buildings. The parallel development of photothermal regulation strategies through both material and system designs has further improved the overall solar utilization efficiency for heating/cooling. In this review, we will review the latest progress in photothermal regulation, including solar heating and passive cooling, and their manipulating strategies. The underlying mechanisms and criteria of highly efficient photothermal regulation in terms of optical absorption/reflection, thermal conversion, transfer, and emission properties corresponding to the extensive catalog of nanostructured materials are discussed. The rational material and structural designs with spectral selectivity for improving the photothermal regulation performance are then highlighted. We finally present the recent significant developments of applications of photothermal regulation in clean energy and environmental areas and give a brief perspective on the current challenges and future development of controlled solar energy utilization.

Three-Dimensional Spiral Evaporator with Side Channels for Efficient Solar-Driven Water Purification

Solar evaporators have the advantages of not consuming fossil fuels, being environmentally friendly, and nonpolluting, offering a promising sustainable method to obtain fresh water and alleviate the worldwide freshwater shortage crisis. In this work, we report that high-performance solar evaporators can be facilely fabricated by processing a cost-effective polypyrrole (PPy)-coated nonwoven fabric (PCNF) into a three-dimensional (3D) spiral structure and introducing side channels for vapor escape. The coated PPy layer ensures excellent photothermal properties and the chemical stability of the evaporator. Meanwhile, the as-created spiral structure of the evaporator can significantly increase the effective evaporation area and harvest energy from the environment, greatly stimulating the evaporation. The side opening channels can effectively facilitate the escape of vapor generated inside the 3D spiral structure, avoid the internal vapor accumulation, and ultimately promote the evaporation of the inner surface, leading to a boost of the evaporation performance. Combining these features, the resulting evaporator exhibits an ultrahigh evaporation rate of 3.26 kg m-2 h-1 and an energy efficiency of 138% under 1-sun irradiation. More importantly, we show that this evaporator can also be used to collect fresh water from soil and sand, demonstrating its great applicability for obtaining potable water in arid areas.

Robust PANI@MXene/GQDs-Based Fiber Fabric Electrodes via Microfluidic Wet-Fusing Spinning Chemistry

Two-dimensional transition metal titanium carbide (Ti3 C2 Tx ) as a promising candidate material for batteries and supercapacitors has shown excellent electrochemical performance, but it is difficult to meet practical applications because of its poor morphology structure, low mechanical properties, and expensive process. Here, an applied and efficient method based on microfluidic wet-fusing spinning chemistry (MWSC) is proposed to construct hierarchical structure of MXene-based fiber fabrics (MFFs), allowing the availability of MFF electrodes with ultrastrong toughness, high conductivity, and easily machinable properties. First, a dot-sheet structure constructed by graphene quantum dots (GQDs) and MXene nanosheets with multianchor interaction in the microchannel of a microfluidic device enhances the mechanical strength of MXene fibers; next, the interfused fiber network structure of Ti3 C2 Tx /GQDs fabrics assembled by the MWSC process enhances the deformability of the whole fabrics; finally, the core-shell structure of PANI@Ti3 C2 Tx /GQDs architected by in-situ polymerization growth of polyaniline (PANI) nanofibers provides more ion-accessible pathways and sites for kinetic migration and ion accumulation. Through the morphology and microstructure design, this strategy has directive significance to the large-scale preparation of conductive fabric electrodes and provides a viable solution for simultaneously enhancing mechanical strength and electrochemical performance of conductive fabric electrodes.

Enhancing Freshwater Production via Customizable and Highly Efficient Solar-Driven Seawater Desalination

Solar-powered water generation is an appealing strategy for cost-effective and energy-sustainable seawater purification/desalination, where rational material selection and device design is crucial. Nevertheless, prevailing carbon-based photothermal materials in such systems still suffer from mediocre steam-to-water efficiency, failing to satisfy an adequate freshwater supply. Herein, we demonstrate a biomimetic corrugated evaporator (CE) affording carbon nanotube (CNT) encapsulated Fe nanocluster-decoration in the pursuit of high-efficiency seawater purification. The thus-customized CE demonstrates a maximum evaporation rate of 4.2 kg m-2 h-1 with a refraction angle of 60° and a water-lifting height of 5.5 cm, outperforming most state-of-the-art carbon-based counterparts. By employing a tailored architectural design and optimized condensing volume, the steam-to-water efficiency increases from 65.8 to 88.2% as the volume enlarges from 0.8 to 5.3 L, further harvesting a peak value of 91% under negative pressure. Light intensity simulation and experimental mechanistic investigation disclose the dual property-performance relationships between evaporator microstructure and evaporation rate, as well as between condensing device volume and steam-to-water efficiency. The universality of the theoretical guidance of this work will offer insight into the development of solar-driven evaporator construction toward simultaneous seawater desalination and clean water generation.

Solar-Powered Interfacial Evaporation and Deicing Based on a 3D-Printed Multiscale Hierarchical Design

Solar-powered interfacial heating has emerged as a sustainable technology for hybrid applications with minimal carbon footprints. Aerogels, hydrogels, and sponges/foams are the main building blocks for state-of-the-art photothermal materials. However, these conventional three-dimensional (3D) structures and related fabrication technologies intrinsically fail to maximize important performance-enhancing strategies and this technology still faces several performance roadblocks. Herein, monolithic, self-standing, and durable aerogel matrices are developed based on composite photothermal inks and ink-extrusion 3D printing, delivering all-in-one interfacial steam generators (SGs). Rapid prototyping of multiscale hierarchical structures synergistically reduce the energy demand for evaporation, expand actual evaporation areas, generate massive environmental energy input, and improve mass flows. Under 1 sun, high water evaporation rates of 3.74 kg m-2 h-1 in calm air and 25.3 kg m-2 h-1 at a gentle breeze of 2 m s-1 are achieved, ranking among the best-performing solar-powered interfacial SGs. 3D-printed microchannels and hydrophobic modification deliver an icephobic surface of the aerogels, leading to self-propelled and rapid removal of ice droplets. This work shines light on rational fabrication of hierarchical photothermal materials, not merely breaking through the constraints of solar-powered interfacial evaporation and clean water production, but also discovering new functions for photothermal interfacial deicing.

Carbon nanofiber reinforced carbon aerogels for steam generation: Synergy of solar driven interface evaporation and side wall induced natural evaporation

Solar-based interface evaporation (SIE) is a green, efficient and cost-effective technique to harvest fresh water. 3D solar evaporators show their unique advantages in gaining energy from environment and hence possess a higher evaporation rate than 2D evaporators. However, much effort is still required to develop mechanically robust and superhydrophilic 3D evaporators with strong water transportation capability and salt-rejection performance, and at the same time reveal how they gain energy from environment via the natural evaporation. In this work, a novel carbon nanofiber reinforced carbon aerogel (CNFA) is prepared for the SIE. The CNFA has a high light absorption up to 97.2% and outstanding photothermal conversion performance. The heteroatom doping and hierarchically porous structure endow the CNFA with superhydrophilicity and thus powerful water transportation capability and salt rejection performance. Benefiting from synergy of the SIE and side wall induced natural evaporation, the CNFA evaporator exhibits a high evaporation rate and efficiency (as high as 3.82 kg m^-2h^-1 and 95.5%, respectively) with long-term stability and durability. The CNFA can also work normally in high-salinity and corrosive seawater. This study demonstrates a new method to fabricate all-carbon aerogel solar evaporators and provides insights for the effective thermal management during the interface evaporation.

Omnidirectionally irradiated three-dimensional molybdenum disulfide decorated hydrothermal pinecone evaporator for solar-thermal evaporation and photocatalytic degradation of wastewaters

Although most solar steam generation devices are effective in desalinating seawater and purifying wastewaters with heavy metal ions, they are ineffective in degrading organic pollutants from wastewaters. Herein, we design novel solar-driven water purification devices by decoration of three-dimensional pinecones with MoS₂ nanoflowers via a one-step hydrothermal synthesis for generating clean water. The vertically arrayed channels in the central rachis and the unique helically arranged scales of the hydrothermal pinecone can not only transfer bulk water upward to the evaporation surface, but also absorb more solar light from different incident angles for solar-thermal evaporation and photodegradation of wastewaters under omnidirectional irradiations. The decorated MoS₂ nanoflowers can not only enhance the solar-thermal energy conversion efficiency, but also decompose organic pollutants in the bulk water by their photocatalytic degradation effects. The resultant hydrothermal pinecone with in situ decorated MoS₂ (HPM) evaporator exhibits a high evaporation rate of 1.85 kg m^-2 h^-1 under 1-sun irradiation with a high energy efficiency of 96 %. During the solar-driven water purification processes, the powdery HPM can also photodegrade organic pollutants of methylene blue and rhodamine B with high removal efficiencies of 96 % and 95 %, respectively. For practical demonstration, by floating in the methylene blue solution under 1-sun irradiation, the bulky HPM can generate clean water by simultaneous solar-thermal evaporation and photocatalytic degradation. The integration of solar steam generation and photocatalytic degradation mechanisms makes the HPM evaporator highly promising for practical high-yield purification of wastewaters.

Hierarchical structure design of sea urchin Shell-Based evaporator for efficient omnidirectional Solar-Driven steam generation

Solar-driven steam generation (SSG) is regarded as a feasible solution to the problem of fresh water scarcity. Although several attempts have been devoted to increase the efficiency of solar-to-steam conversion, it remains difficult to fabricate cost-effective, steady, and multi-angle sunlight-absorbing evaporators from readily available biomass materials. Herein, a novel hierarchical structured SSG evaporator (PDA@Shell-NaClO) is developed through a simple, low-cost, and scalable etching treatment on discarded sea urchin (SU) shells. Attributing to the dedicatedly designed microneedles array structure and porous skeleton structure of the SU shell, this PDA@Shell-NaClO evaporator shows an outstanding average light absorption performance (>90%) in a broad range of angles from 0° to 60° and exceedingly high evaporation rate of 2.81 kg m^-2 h^-1 under one sun condition. Furthermore, the prepared evaporator also maintains an overall stable evaporation performance and exhibits an excellent durability for a long time of up to two weeks in actual seawater. This full-ocean biomass-based SSG evaporator with plentiful raw material availability offers innovative opportunities for large-scale fresh water production.

Overflow Control for Sustainable Development by Superwetting Surface with Biomimetic Structure

Liquid flowing around a solid edge, i.e., overflow, is a commonly observed flow behavior. Recent research into surface wetting properties and microstructure-controlled overflow behavior has attracted much attention. Achieving controllable macroscale liquid dynamics by manipulating the micro-nanoscale liquid overflow has stimulated diverse scientific interest and fostered widespread use in practical applications. In this review, we outline the evolution of overflow and present a critical survey of the mechanism of surface wetting properties and microstructure-controlled liquid overflow in multilength scales ranging from centimeter to micro and even nanoscale. We summarize the latest progress in utilizing the mechanisms to manipulate liquid overflow and achieve macroscale liquid dynamics and in emerging applications to manipulate overflow for sustainable development in various fields, along with challenges and perspectives.

Promoted Photothermal Catalytic CO Hydrogenation by Using TiC-Supported Co-Fe5 C2 Catalysts

Photothermal catalytic CO hydrogenation offers the potential to synthesize light hydrocarbons by using solar energy. However, the selectivity and activity of the reaction are still far below those achieved in conventional thermal catalytic processes. Herein, we report that the Co-modified Fe₅ C₂ on TiC catalyst promotes photothermal catalytic CO hydrogenation with a 59 % C₂₊ selectivity in the produced hydrocarbons and a 30 % single-pass CO conversion at a high gas hourly space-time velocity of 12 000 mL g^-1  h^-1 . Using in-situ-irradiated XPS, we show that light-induced hot electron injection from TiC to Fe₅ C₂ modulates the chemical state of Fe, thereby increasing the CO-to-C₂₊ conversion. This work suggests that it is possible for plasmon-mediated surface chemistry to enhance the activity and selectivity of photothermal catalytic reactions.

Photothermal Aerogel Beads Based on Polysaccharides: Controlled Fabrication and Hybrid Applications in Solar-Powered Interfacial Evaporation, Water Remediation, and Soil Enrichment

Solar-powered interfacial evaporation has emerged as an innovative and sustainable technology for clean water production. However, the rapid, mass and shape-controlled fabrication of three-dimensional (3D) steam generators (SGs) for versatile hybrid applications remains challenging. Herein, composite aerogel beads with self-contained properties (i.e., hydrophilic, porous, photothermal, and durable) are developed and demonstrated for threefold hybrid applications including efficient solar-powered interfacial evaporation, water remediation, and controlled soil enrichment. The rational incorporation of selected polysaccharides enables us to fabricate bead-like aerogels with rapid gelation, continuous processing, and enhanced ion adsorption. The composite beads can attain a high water evaporation rate of 1.62 kg m-2 h-1 under 1 sun. Meanwhile, high phosphate adsorption capacity of over 120 mg g-1 is achieved in broad pH (2.5-12.4) and concentration (200-1000 mg L-1) ranges of phosphate solutions. Gratifyingly, we demonstrate the first example of recycling biomaterials from interfacial SGs for controlled nutrient release, soil enrichment, and sustainable agriculture. The phosphate-saturated beads can be gradually broken down in the soil. Macronutrients (N, P, and K) can be slowly released in 50 days, sustaining the plant germination and growth in a whole growth stage. This work shines light on the mass and controlled fabrication of aerogel beads based on double-network biopolymers, not merely scaling up solar-powered interfacial evaporation but also considering water remediation, waste material disposal, and value-added conversion.

Dual-Layer Multichannel Hydrogel Evaporator with High Salt Resistance and a Hemispherical Structure toward Water Desalination and Purification

Interfacial solar steam generation technology has been considered as one of the most promising methods for seawater desalination. However, in practical applications, salt precipitation on the evaporation surface reduces the evaporation rate and impairs long-term stability. Herein, a dual-layer hydrogel-based evaporator that contains a microchannel-structured water-supplying layer and a nanoporous light-absorbing layer was synthesized via sol-gel transition and "hot-ice" template methods. Contributed by the designed structure-induced accelerated salt ion exchange, the hemispherical dual-layer hydrogel evaporator showed excellent salt formation resistance property, as well as a high evaporation rate reaching 2.03 kg m^-2 h^-1 even under high brine concentration conditions. Furthermore, the hydrogel-based evaporator also demonstrated excellent ion rejection, high/low pH tolerance, and excellent purification properties toward heavy metals and organic dyes. It is believed that this type of dual-layer multichannel evaporator is promising to be used in seawater desalination, water pollution treatment, and other environmental remediation-related applications.

Template synthesis of dual-functional porous MoS2 nanoparticles with photothermal conversion and catalytic properties

Advanced catalysis triggered by photothermal conversion effects has aroused increasing interest due to its huge potential in environmental purification. In this work, we developed a novel approach to the fast degradation of 4-nitrophenol (4-Nip) using porous MoS₂ nanoparticles as catalysts, which integrate the intrinsic catalytic property of MoS₂ with its photothermal conversion capability. Using assembled polystyrene-b-poly(2-vinylpyridine) block copolymers as soft templates, various MoS₂ particles were prepared, which exhibited tailored morphologies (e.g., pomegranate-like, hollow, and open porous structures). The photothermal conversion performance of these featured particles was compared under near-infrared (NIR) light irradiation. Intriguingly, when these porous MoS₂ particles were further employed as catalysts for the reduction of 4-Nip, the reaction rate constant was increased by a factor of 1.5 under NIR illumination. We attribute this catalytic enhancement to the open porous architecture and light-to-heat conversion performance of the MoS₂ particles. This contribution offers new opportunities for efficient photothermal-assisted catalysis.

Thermo-photo catalysis: a whole greater than the sum of its parts

Thermo-photo catalysis, which is the catalysis with the participation of both thermal and photo energies, not only reduces the large energy consumption of thermal catalysis but also addresses the low efficiency of photocatalysis. As a whole greater than the sum of its parts, thermo-photo catalysis has been proven as an effective and promising technology to drive chemical reactions. In this review, we first clarify the definition (beyond photo-thermal catalysis and plasmonic catalysis), classification, and principles of thermo-photo catalysis and then reveal its superiority over individual thermal catalysis and photocatalysis. After elucidating the design principles and strategies toward highly efficient thermo-photo catalytic systems, an ample discussion on the synergetic effects of thermal and photo energies is provided from two perspectives, namely, the promotion of photocatalysis by thermal energy and the promotion of thermal catalysis by photo energy. Subsequently, state-of-the-art techniques applied to explore thermo-photo catalytic mechanisms are reviewed, followed by a summary on the broad applications of thermo-photo catalysis and its energy management toward industrialization. In the end, current challenges and potential research directions related to thermo-photo catalysis are outlined.

Composite Polyelectrolyte Photothermal Hydrogel with Anti-biofouling and Antibacterial Properties for the Real-World Application of Solar Steam Generation

Solar steam generation provides a promising and low-cost solution for freshwater production in energy scarcity areas. However, in real-world applications, evaporators are easily affected by microorganism contamination in source water, causing surface corrosion, structural damage, or even invalidation. Developing anti-biofouling and antibacterial evaporators is significant for long-term stable freshwater production. Herein, a composite polyelectrolyte photothermal hydrogel consisting of sulfobetaine methacrylate (SBMA), [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC), and polypyrrole (PPy) with anti-biofouling and antibacterial properties is developed. Crediting sufficient ammonium groups and zwitterionic segments, the optimized polyelectrolyte hydrogel exhibits an ∼90% antibacterial ratio against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and effectively controls biological contamination. Under 1.0 kW m^-2 solar irradiation, a rapid water evaporation rate of ∼1.690 kg m^-2 h^-1 and a high solar-to-evaporation efficiency of ∼95.94% are achieved with the photothermal hydrogel. We show that a lab-made setup integrated with the hydrogel can realize ∼0.455 kg m^-2 h^-1 freshwater production from seawater under natural sunlight. Moreover, the hydrogel exhibits excellent durability with a stable evaporation rate of ∼1.617 kg m^-2 h^-1 in real seawater for over 6 weeks, making it fullhearted in the real-world application of solar steam generation.