The photothermal hydrogels based on dual-active centers for volatile organic compound simultaneous removal in efficient water purification production

Abstract

Solar-driven interfacial evaporation (SIE) represents a frontier technology for sustainable water treatment and freshwater reclamation. Nevertheless, the enrichment of volatile organic compound (VOC) with high ecotoxicity and environmental persistence from original water into the distilled water during the evaporation process contaminates the water quality, significantly posing a critical challenge for SIE technology. Herein, bifunctional photo-thermal hydrogel evaporators integrating Ti₃C₂/CuS composites (TCHs) were constructed for simultaneous solar evaporation and activated peroxymonosulfate (PMS) catalyzed degradation of VOC to obtain clean water. The TCHs exhibited an evaporation rate of 2.24 kg m^-2 h^-1 under 1.0 solar irradiation intensity. The interfacial structure formed by coupling Ti₃C₂ and CuS facilitates the rapid transfer of charge carriers, thereby establishing dual-active centers for the activation of PMS, and the system achieved 95.4 % phenol removal efficiency from distilled water. Sulfate radicals (SO₄^-) and singlet oxygen (¹O₂) non-radicals jointly played a key role in the photothermal evaporation coupled PMS catalytic system. This research provides an efficient cyclical solution for water purification and freshwater generation.

Keywords: Catalytic degradation; Hydrogel; Solar evaporation; Ti(3)C(2)/CuS; VOC.