Transition-Metal Sulfide/Carbon Composites Derived from Recycled Sulfonated Resin as High-Photothermal-Conversion Materials for Solar-Driven Interfacial Evaporation

The objective of this study is to investigate the recycling and utilization of Amberlyst 15 resin, which contains sulfonic acid groups, with the aim of transforming it into an excellent photothermal conversion material to enhance interfacial water evaporation capability. By pyrolyzing the resin and transition metal salt composite, composite materials of transition metal sulfides and carbon (Cu7S4-C, Ni3S2-C, and Co3S4-C) were successfully prepared, which combine the electron-phonon coupling effect and localized surface plasmon resonance (LSPR) effect. The prepared materials were characterized in detail. The results of evaporation experiments using distilled water indicated that the net evaporation rates of water evaporators constructed from Cu7S4-C, Ni3S2-C, and Co3S4-C reached 1.23, 1.06, and 1.15 kg·m−2·h−1, respectively, under one-sun irradiation, exhibiting photothermal conversion efficiencies of 85.7%, 73.8%, and 80.1%, respectively. This study proposes a sustainable resource utilization method for solid waste sulfonic acid resin, and based on this, develops a new type of photothermal conversion material suitable for solar-driven interfacial water evaporation systems.