Carbonized Sweet Potato-Based Evaporator for Highly Efficient Solar Vapor Generation

Solar vapor generation has been considered an appealing way to solve freshwater scarcity issues. Although several natural materials have been developed, the exploration of biomass materials with stable evaporation, simple processes, and low energy consumption is still necessary. Herein, sweet potato, a high-yield natural plant, is explored to prepare a solar evaporator with a cross-linked porous structure. Carbonized sweet potato exhibits a high evaporation rate of 1.7 kg m-2 h-1 and an excellent solar-thermal conversion efficiency of 76% under 1 sun. This demonstrates excellent photothermal ability and enhanced water evaporation performance. Thanks to the unobstructed cross-linking structure and fast water transport, the salt does not accumulate on the evaporator's surface in high-salinity brine (10-20 wt% NaCl) and the evaporation rate is 1.35 kg m-2 h-1. This suggests superior evaporative stability and self-desalting capability. The purpose of this study is to provide an eco-friendly, stable, and efficient evaporator, with salt resistance by simple processes, and to demonstrate the potential application of biomass materials in solar vapor generation. Carbonized sweet potato-based evaporators with salt resistance can be obtained by a simple preparation method. The evaporator exhibits excellent steam generation performance, achieving an evaporation rate of 1.7 kg m-2 h-1 under 1 sun irradiation, and after evaporation under high salinity, the evaporator still exhibits excellent self-desalting properties.image (c) 2023 WILEY-VCH GmbH