Bifunctional Co3O4 porous nanosheet arrays fabricated on compacted stainless steel mesh for comprehensive solar energy utilization

Integrating photothermal catalytic degradation functionality into solar-driven interfacial evaporation systems offers an efficient strategy for purifying organic wastewater and mitigating the accumulation of organic pollutants on solar absorber surfaces. In this study, a comprehensive solar energy utilization system was accomplished by synthesizing Co 3 O 4 porous nanosheets on the compacted stainless steel mesh (CSSM) as solar absorbers. This system simultaneously harnessed interfacial heat to drive water evaporation and enhanced photodegradation through photothermal effects. Under simulated sunlight irradiation, the system achieved an interfacial water evaporation rate of 1.39 kg m −2 h −1 and a photothermal degradation efficiency of 90.1 % for RhB, confirming their dual functionalities in water evaporation and photothermal catalytic treatment of wastewater. Furthermore, owing to the superior acid-base and corrosion resistance of CSSM, Co 3 O 4 /CSSM was well-suited for water purification applications across various water quality conditions. Under outdoor illumination, Co 3 O 4 /CSSM demonstrated a water evaporation rate of 1.04 kg m −2 h −1 and achieved nearly 100 % photothermal catalytic degradation efficiency for RhB. Additionally, the concentrations of Na⁺, Mg²⁺, Ca²⁺, and K⁺ in the evaporated water met the drinking water standards established by the WHO. This study, utilizing CSSM as a substrate the flexible material, introduces an innovative approach towards achieving zero-emission dye wastewater treatment.