Synchronizing Efficient Purification of VOCs in Durable Solar Water Evaporation over a Highly Stable Cu/W₁₈O₄₉@Graphene Material

Solar-driven clean water production is challenged by VOCs (volatile organic compounds), which pose health risks in distilled water. Herein, we developed a Cu/W₁₈O₄₉@Graphene photothermal-photocatalytic material addressing VOCs contamination. Plasmonic coupling between Cu and W₁₈O₄₉ enhances light absorption, and 1-2 layers of graphene encapsulation protects oxygen vacancies within W₁₈O₄₉ while facilitating hot electron extraction, effectively mitigating their ultrafast relaxation. Density functional theory calculations revealed enhanced VOCs adsorption on graphene. These synergies address oxygen vacancy decay in W₁₈O₄₉ and provide more active sites for gas-liquid-solid triphase photocatalytic reactions. Integrated with a three-dimensional floating evaporator substrate, the optimized Cu/W₁₈O₄₉@Graphene material achieved an effective water evaporation rate of 1.41 kg m^-2 h^-1 (efficiency of 88.6%), exceptional stability (>120 h), and remarkable 99% phenol removal under 1 sun irradiation (1 kW m^-2). This work provides a promising solution to mitigate VOCs contamination in solar-driven water evaporation.