A Solar Evaporator Based on Waste Biomass Material for Water Evaporation and Thermoelectric Conversion Application

Abstract High‐performance photothermal materials are indispensable for interfacial solar evaporation technology. The utilization of biomass‐based photothermal materials has emerged as a promising approach for interfacial solar‐driven evaporation, primarily due to their advantageous characteristics, including low production costs, large specific surface area, environmental friendliness, and renewable characteristics. Biomass photothermal materials. In this study, as a kind of waste, cigarette ash contains a high concentration of carbon particles, which can exhibit remarkable photothermal conversion capability (18.30%), positioning it as a novel biomass‐derived photothermal material for solar energy harvesting. In addition, a low‐cost and environmentally friendly evaporator is prepared by combining a non‐woven fabric with WCA (waste cigarette ash) and the evaporation rate of the evaporator reaches 1.16 kg m −2 h −1 with an evaporation efficiency of 80.55%. Then, a unidirectional salt collection device that can achieve long‐term salt collection and generate electrical energy is designed. Water‐electricity cogeneration is designed to efficiently utilize the thermal energy released during the water evaporation process, with voltage reaching 57.1 mV under 1.0 kW m −2 solar irradiation. The WCA evaporator provides an innovative perspective on waste utilization in solar‐driven seawater desalination.