Photothermal activation of peroxydisulfate for simultaneous solar evaporation and water purification using non-powered capillary fabric

Solar evaporation is a promising method for water purification, but it often faces challenges such as scale formation of organics after feed water evaporation and low efficiency in evaporation. In response, we created a dual-function system based on the photothermal active peroxydisulfate (PDS) technique. The system serves both double-sided evaporation to improve evaporation efficiency and simultaneous removal of organic contaminant scale accumulation. Wastewater containing PDS is extracted by capillary force through a photothermal fabric, evaporating on both surfaces under sunlight. Concurrently, the thermal energy generated during the steam generation process can break the O-O bond of PDS, generating sulfate radicals (SO 4 & sdot;- ) that decompose organic pollutants. The design achieves a rapid evaporation rate of 5.47 kg m- 2 h-1 and a high solar efficiency of 89.9 % under sunlight irradiation (4000 W/m 2 ). Additionally, it demonstrates a 99.8 % RhB removal efficiency in concentrated brine. Importantly, highly concentrated brine can be collected without solid-salt accumulation. This development enhances the potential of solar distillation for wastewater treatment.