The Effect of Co-Modification of Ultrathin G-C3n4 Nanosheets with Ag and S on Photocatalytic Hydrogen Production

Abstract

Photocatalytic water splitting is a promising technology for hydrogen (H2) production. However, its development is severely limited by the deficient active sites and low efficiency of photogenerated carriers. In this study, we successfully fabricated Ag-S-CN ultrathin nanosheets through the co-modification of graphitic carbon nitride (CN) with silver (Ag) and sulfur (S). Sulfur doping in the intralayer of CN broadens light absorption and provides more reaction sites, while the introduction of Ag into the interlayers of CN enhances the migration rate of photogenerated carriers between adjacent layers via Ag-S bonds. Consequently, 0.05 Ag-S-CN achieves a high H2 yield of 0.93 mmol g-1 h-1 without the need for any additional cocatalyst, which is about 23.25 times and 10.33 times higher than CN and S-CN, respectively. This work presents an effective strategy for developing highly efficient photocatalysts.

Keywords: g-C3N4, Ag and S co-doping, Carrier separation, Active site, Photocatalytic H2 evolution