New bidental sulfur-doped graphene quantum dots modified with gold as a catalyst for hydrogen generation.

Disadvantages of fossil fuels encourage researchers to develop clean combustion sources, in particular, H2 due to the high potential energy and safe by-products. Herein, Au was deposited on S-doped graphene quantum dots to obtain a heterogeneous photocatalyst for the degradation of formic acid toward H2 generation. Insertion of thiol groups on graphene quantum dots was carried out by self-condensation reaction of citric acid in the presence of Dimaval, as the thiol groups carrier. After the complexation of Au with the prepared S-doped graphene quantum dots, the catalytic activity of composite was evaluated in formic acid degradation to generate H2 under visible light. Au@S-doped graphene quantum dots demonstrated superior catalytic activity with the turnover frequency up to 112 h-1. The reaction enjoys significant benefits such as stability and recyclability of the catalyst, excellent reaction rate, and mild reaction conditions.