Flexible CuInS2 nanosheet arrays for simultaneous realization of solar water evaporation and photothermal-enhanced photodegradation

This study aims to develop a high-efficiency solar energy utilization system for water purification by synthesizing porous CuInS 2 (CIS) nanosheet arrays on a compacted stainless steel mesh (CSSM) using a facile solvothermal method. The CIS/CSSM system leverages interfacial heat to drive water evaporation and enhance photodegradation via photothermal effects. The porous architecture of both the CSSM and the black CIS nanosheets significantly improves light collection efficiency, achieving a solar absorption rate of 97.3 %, thereby facilitating efficient photothermal conversion. Under simulated 1-sun illumination, the system attains an evaporation rate of 1.43 kg m −2  h −1 with a high evaporation efficiency of 93.01 %. The cost-effective CSSM possesses robust chemical stability, making the CIS/CSSM an efficient solar purification system capable of distilling clean water from seawater, river water, and highly acidic/alkaline solutions. Furthermore, the system demonstrates excellent photothermal catalytic degradation, achieving 88.1 % degradation of ciprofloxacin solution. In outdoor sunlight, the system simultaneously maintains an evaporation rate of 1.23 kg m −2  h −1 and a photothermal degradation efficiency of 80.7 %, highlighting its potential application in water purification. This study integrates photothermal catalysis with solar-driven interfacial evaporation, offering a novel and efficient approach for wastewater treatment and water purification.