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

Abstract 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)2SO4 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)2SO4, and shows a highly improved efficiency 8.4 times that of bulk g-C3N4 in visible-light photocatalytic H2 evolution. The improved performance mainly benefits from the enlarged specific surface area, enhanced light absorption and improved separation efficiency of photo-induced charge carriers. This work may inspire the facile synthesis of other nanostructured and doped g-C3N4.