Black g-C3N4-based hydrogel for water evaporation and photothermal persulfate activation

Integrating the evaporation of seawater at the interface with the treatment of wastewater presents an encouraging approach to address urgent energy and environmental issues. Nevertheless, the development of dual-function evaporators endowed with synergistic photothermal advanced oxidation catalytic properties presents significant hurdles. In this study, a black g-C₃N₄/loofah/chitosan (BCN/LF/CS) hydrogel was developed, demonstrating remarkable abilities in absorbing sunlight and converting it thermally. This innovation is intended for solar-driven evaporation and the thermal activation of persulfate (PS), which aids in the degradation of tetracycline (TC) contaminants. Test results demonstrated that under singular sunlight irradiation, BCN/LF/CS hydrogel not only achieves an impressive evaporation rate of 2.5 kg m⁻² h⁻¹ but also effectively catalyzes the decomposition of PS, leading to substantial degradation of TC (Concertation: 50 mg/L, PS dose: 0.03 g/L, 86% degradation rate: in 3 h). The research unveils innovative and ingenious methodologies to alleviate freshwater scarcity and address the pressing issue of water pollution which introduces a groundbreaking approach to the development of advanced solar evaporators that seamlessly integrate seawater desalination with sewage purification.