Dual-functional paper-like evaporator for boosting interfacial evaporation synchronized with organic pollutant degradation

Abstract

Solar-driven interfacial evaporation is a sustainable method to produce freshwater, but volatile organic compounds (VOCs) inevitable accumulate in the condensed water, causing secondary pollution. Herein, paper-like photothermal evaporators were constructed by fixing zeolitic diazoate frameworks-8 derived N-doped carbon with different morphologies on the interwoven cellulose nanofibrils (CNFs) membranes for simultaneous steam generation and organic pollutant degradation. The results showed that the evaporator incorporated porous N-doped carbon with rhombic dodecahedron (NC-RD) into CNFs membranes not only increases the roughness to achieve broad spectrum solar absorption, but also capable of ensuring continuous evaporation of water, and maintaining a sufficient water supply. The NC-RD/CNFs membranes exhibit the high evaporation rate of 1.46 kg·m−2·h−1 under one sun. Meanwhile, N-doped carbon enable photothermal-synergistic peroxymonosulfate (PMS) activation to promote the generation of abundant 1O2 and O2∙– for degradation of methylene blue, tetracycline and phenol. Furthermore, the solar-vapor conversion efficiency and the evaporation rate are stable in a simulated seawater environment with 15 wt% NaCl solution. Importantly, an outdoor NC-RD/CNFs-based device was constructed, which realizes a high evaporation rate of 0.659 kg∙m−2∙h−1 under natural light irradiation for 10 h. The present study highlights that the NC-RD/CNFs membranes successfully coupled interfacial evaporation with PMS based-advanced oxidation processes to provide a subtlety strategy to solve the problem of VOCs accumulation in the evaporation process.