Simultaneous efficient evaporation and stable electricity generation enabled by a wooden evaporator based on composite photothermal effect

The current solar interfacial evaporators have limited evaporation performance due to their single photothermal mechanism, insufficient light utilization, and improper heat management. Therefore, a novel approach involving polypyrrole (PPy) and Ag nanoparticles (AgNPs) modified wooden evaporator (AgPW) using an in-situ polymerization and growth method was proposed for efficient and sustainable freshwater purification. The composite photothermal effect of PPy and AgNPs led to a significantly enhanced light absorption capacity and superior photothermal conversion efficiency in a wide spectrum range, which coupled with the rapid water transport capacity conferred by the regular vertical channels and superior hydrophilicity of the delignified wood, resulted in remarkable evaporation performance through the coordinated regulation of thermal and water management. The optimized AgPW50 achieved an evaporation rate of up to 2.04 kg m −2 h −1 and an evaporation efficiency of 90.7 % under 1 kW m −2 irradiation. Importantly, this evaporator was highly salt resistant and long-term desalination stability, and can also be extended to the purification of various types of wastewaters while converting the released waste heat into stable electricity generation. The innovative Ag/PPy wooden evaporator integrates biomass resources with solar energy utilization, demonstrating an environmentally friendly, efficient and cost-effective strategy for seawater desalination and energy production, providing a new sustainable development pathway to solve the challenge of balancing water security and energy consumption.