Molecular engineering of a synergistic photocatalytic and photothermal membrane for highly efficient and durable solar water purification

In recent years, the solar-driven interfacial evaporation system (SIES) has obtained a lot of interest as a potential solution to freshwater scarcity. However, the organic pollutant residues affected the practical application of the distillate generated by SIES. Herein, a solar interfacial membrane (AuNPs@g-C 3 N 4 /CMF) (AMF) for desalination and removal of multiple water pollutants was prepared by generating Au-doped carbon nitride (AuNPs@g-C 3 N 4 ) directly on the carbonized melamine (CMF) through a co-calcination process. The designed membrane features excellent light absorption, efficient water supply, and low thermal conductivity . All the above advantages of the AMF membrane contributed to an outstanding evaporation rate (1.675 kg m -2  h -1 ) and high photothermal conversion efficiency (94.03%) under 1 sun irradiation. For seawater desalination, the membrane performed well in removing ions from simulated seawater and demonstrated good stability during long-term desalination. Meanwhile, the membrane still exhibits a high evaporation rate (1.24 kg m -2  h -1 ) even in a 10% salt solution environment. Owing to the photocatalysis capability of AuNPs@g-C 3 N 4 , the AMF membrane also performs effectively in the removal of organic dyes and formaldehyde.