Bimetallic composite carbon fiber with persulfate mediation for intercepting volatile organic compounds during solar interfacial evaporation

Solar interfacial evaporation (SIE), is currently one of the most potential water supply technologies in the remote, insular, and disaster-stricken areas. However, the existence of volatile organic compounds (VOCs) in water deteriorates the distillate quality, threatening human health. Herein, we constructed a carbon-based bimetallic (C/FeCo) photothermal membrane by electrospinning technique. Results illustrated that the membrane can catalytically degrade VOCs during SIE with persulfate (PDS) mediation. PDS, as well as phenol, was mainly reacted on the interface of the photothermal membrane instead of in the bulk solution. The interception efficiency of phenol achieved nearly 100% using the C/FeCo membrane during SIE. Hydroxyl radical (•OH), sulfate radical (SO4•−), superoxide radical (O2•−), and singlet oxygen (1O2) were identified as the main active substances to degrade VOCs. We also conducted SIE experiments using actual river water to evaluate the practical performance of the C/FeCo membrane. This work holds the promise of VOCs interception during SIE and enlarges the application of solar distillation in water/wastewater treatment.