One-step synthesis of S-doped g-C3N4 nanosheets for improved visible-light photocatalytic hydrogen evolution

A facile gas-templating method was developed to realize the synchronous nano-structuring and S-doping of g-C3N4 in one step. It uses the bottom-placed (NH4)(2)SO4 as a bi-functional gas template source and doping agent to transform the up-placed melamine into S-doped g-C3N4 nanosheets (SCN-20). SCN-20 is much superior to the counterpart synthesized from the mixed melamine and (NH4)(2)SO4, and shows a highly improved efficiency 8.4 times that of bulk g-C3N4 in visible-light photocatalytic H-2 evolution. The improved performance mainly benefits from the enlarged specific surface area, enhanced light absorption and improved separation efficiency of photoinduced charge carriers. This work may inspire the facile synthesis of other nanostructured and doped g-C3N4.