All-in-one solar-driven evaporator for high-performance water desalination and synchronous volatile organic compound degradation

Solar-driven evaporation is thought to be a fantastic strategy for freshwater generation, but the evaporated vapor inevitably accumulates volatile organic compounds (VOCs) in the initial wastewater, leading to secondary pollution of the condensed water. Here we demonstrate a dual-functional solar evaporator based on the graphite-N (g-N) doped biochar derived from biomass waste for simultaneous desalination and VOCs degradation. The doped g-N can activate potassium peroxomonosulfate (PMS) to produce plenty of singlet oxygen (O-1(2)) and thus decomposing VOCs, whereas numerous micropores can capture VOCs. Taking wood biomass waste as an example, its derived g-N doped wood carbon (g-N/WC) evaporator delivers a high degradation efficiency of similar to 99.91 % toward VOCs (including phenol, Bisphenol A (BPA), 4,4'-Sulfonyldiphenol (BPS), and p-Chlorophenol (4-CP)), and a great evaporation rate of 1.31 kg m(-2) h(-1) under 1 sun. Life cycle assessment (LCA) results demonstrate that the environmental impacts across all categories and CO2 emissions of the g-N/WC evaporator are reduced by up to 98 % and 82 %, respectively, compared with other emerging materials. The developed solar evaporator repurposes biomass waste to simultaneously solve water scarcity and waste mismanagement crises with an extremely low carbon footprint, representing a promising approach toward worldwide sustainable wastewater purification and biomass waste management.