Multifunctional MXene wood-based evaporator fabricated by repeated brush-coating for solar steam generation and evaporation power generation

Solar-driven interfacial evaporation is regarded as an effective method for obtaining clean water and addressing the freshwater crisis, from the perspective of an academic researcher. Wood, as a natural and renewable biomass material, is considered an excellent substrate for fabricating evaporators due to its lightweight nature and tunable porous structure. However, current wood-based evaporators face challenges such as the difficulty in balancing evaporation performance with fabrication cost, and the limitation to single-form energy utilization. To overcome these issues, we propose a simple fabrication process for a wood-based evaporator. This method achieves high evaporation performance while enabling rapid preparation. In this study, symmetric MXene coatings are applied on both faces of delignified wood by brushing MXene back and forth along a fixed direction. The delignified wood facilitates rapid water transport and combined with the high photothermal conversion efficiency of MXene, the back-and-forth brushing induces controlled stacking and aggregation of MXene, thereby enhancing light utilization efficiency. By tilting the evaporator on the water surface, an additional evaporation area is introduced. The optimized MXene-Delignified Wood evaporator achieves a solar absorption rate of 90.21%, a maximum evaporation rate of 2.151 kg·m⁻²·h⁻¹ , and an efficiency of 105.07% under one sun irradiation, significantly exceeding the theoretical limit of two-dimensional evaporators (1.47 kg·m⁻²·h⁻¹). Under simulated sunlight, an increase in power output is achieved. Experimental results have confirmed that this evaporator can also be applied to degrade organic wastewater containing methyl orange and methylene blue.