Kesterite Cu2ZnSnS4 thin-film solar water-splitting photovoltaics for solar seawater desalination

Kesterite photovoltaic materials of Cu2ZnSnS4 (CZTS) thin films present excellent photoelectrochemical (PEC) properties in solar water-splitting devices. It is found that photoelectrodes, including CZTS for solar water splitting, are suitable for application in solar seawater desalination due to the similarity of their operation principle and work conditions to photoelectrodes/solutions. Here we report the application of a CZTS-based photocathode from solar water splitting to solar seawater desalination. With the TiO2 surface modification layer, the CZTS-based photocathode shows superior stability in the progress of seawater desalination and maintains desalination performance above 95% after testing for almost 500 h. Moreover, the device driven by solar energy does not require an additional electrical supply. The combination of redox flow and ion exchange membrane (IEM) for seawater desalination is a highly efficient and promising water treatment technique that can effectively alleviate the shortage of freshwater resources.