Construction of covalent organic framework evaporator based on Bi/BiOCl floating layer and its application in solar desalination and clean water production

Solar interface heating evaporators are widely used and have been able to obtain clean water vapor from sewage. However, the soluble contaminants remaining in the original solution were not removed, and the floating organic pollutants affect the steam production rate. In this paper, the superhydrophobic Bi/BiOCl with low surface tension is synthesized and loaded to the felt to construct the floating layer of the photothermal device. The floating layer collaborated with the filter paper hydrophilic layer and the Pyromellitic dianhydride-Tris (4aminophenyl) amine covalent organic framework (PMDA-TAPA COF) photothermal layer to treat the sewage containing dissolved pollutants, achieving an interfacial evaporation rate of 1.47 kg.m (-2).h (-1). Importantly, the floating layer not only has a contact angle of 161., which can selectively adsorb the organic solvents floating on the water surface, but also can degrade the pollutants dissolved in the water under the light and solving the problems that hinder device applications. The valence band and conduction band potentials of superhydrophobic Bi/BiOCl are at 3.065 eV and 0.435 eV, respectively, which produce h(+) and .O-2 (-) under light to degrade dissolved pollutants in water. The introduction of novel superhydrophobic Bi/BiOCl photocatalyst in the floating layer provides a reference for solving the problem of pollutant residues.