Vacancy defects assist solar interfacial evaporator to realize simultaneously clean water production and pollutant removal

Abstract

It is crucial for relieving the shortage of clean water in inland to construct an economical photothermal interfacial evaporator with a function of solving the enrichment of dyes during clean water production. Herein, a photothermal interfacial evaporator satisfying the above acquirement is constructed, in which BiOBr with oxygen vacancies (BiOBr-OVs) serves as photothermal material, which lays a foundation for preparation of a photothermal interfacial evaporator with an ability of avoiding dyes aggregation during clean water production. Furthermore, the raw materials except photothermal material and sodium alginate coating of the evaporator are from daily life, which reduces its cost. Importantly, the evaporation rate of the evaporator under one sun illumination is 4.2 times that of pure water (0.39 kg·m−2·h−1). Meanwhile, it also exhibits a purification efficiency of 99.9 % for Rh B solution. Noteworthily, Rh B in bulk water is photodegraded by the evaporator during steam generation under one sun illumination and its photodegradation efficiency is 99.9 %, indicating that the evaporator is capable of preventing dye aggregation during water evaporation. Besides, the evaporator has desalination performance, in which its steam generation rates in 3.5 wt% and 10 wt% NaCl solution are attenuated only by 1.23 % and 3.07 %, respectively, compared with that of in pure water. Meanwhile, the removal efficiency of the evaporator for K+, Na+ and Mg2+ in simulated seawater is 99.98 %.