Plasmon-enhanced light absorption and photothermal conversion in ReS(2)/CoS(2)/Cu(2-x)S hollow nanostructures for efficient solar water evaporation.

The rational design of high-performance photothermal material and solar evaporator is crucial for efficient solar steam generation, yet it remains a significant challenge. In this study, a plasmonic ReS/CoS/CuS hybrids integrated into a three-dimensional columnar evaporator were developed, demonstrating broadband light absorption, efficient photothermal conversion, and exceptional solar evaporation performance. The hollow-structured ReS/CoS/CuS hybrids were synthesized via a facile hydrothermal method, exhibiting remarkable photothermal conversion efficiency (46.7 % under 808 nm excitation) attributed to its unique plasmonic resonance, narrow bandgap characteristics, and hollow architecture. When loaded onto a cotton piece, the ReS/CoS/CuS-based two-dimensional membrane achieved a high evaporation rate of 2.09 kg m h with a solar-to-vapor efficiency of 98.58 % under 1 sun irradiation, owing to its superior light absorption (∼94 %). Furthermore, a three-dimensional columnar evaporator based on the ReS/CoS/CuS membrane was designed, which has adjustable height exposed in air and tunable depth immersed in water. This evaporator yielded a high evaporation rate of 4.88 kg m h with 122.13 % efficiency, which can be attributed to the additional energy harvesting from the cold evaporation surfaces and rapid water transport enabled by hydrophilic root structures. Practical applications in seawater desalination, wastewater treatment, and outdoor evaporation experiments confirmed the system's robustness for potable water production and water purification.