Bamboo fiber-reinforced chitosan sponge as a robust photothermal evaporator for efficient solar vapor generation

Abstract

The severe problem of water scarcity has led to the derivation and rapid development of solar vapor generation (SVG) technology. However, high cost, short-term stability in harsh environments, and potential secondary pollution restrict the practical application of most solar evaporators, especially in economically underdeveloped areas. Herein, we design a low-cost and long-term stable sponge evaporator by combining carbonized pomelo peel particles (CPPs) with chitosan (CS) and bamboo fibers (BFs) for efficient solar vapor generation. Due to the interactive macroporous architecture formed by BF's random interspersion in chitosan lamellae and the excellent CPP solar absorbers, the obtained robust CS/BFs/CPPs sponge evaporator exhibits a water evaporation rate of 2.317 kg m⁻² h⁻¹ with an energy conversion efficiency of 89.23% under one sun illumination. In addition, this sponge evaporator can work in harsh water environments such as acid–base solutions, dye solutions, and high salinity brine for long periods of time because of the stable interactive structure. More importantly, since all green materials for constructing the evaporator belong to the natural world, we demonstrate, the first example of ageing evaporator that can be reutilized and transformed into the soil. This work not only highlights the potential for developing low-cost and long-term durable solar evaporators but also contributes to the research direction for recycling and reutilization of ageing evaporators.