Enhanced visible-light photocatalytic nitrogen fixation over semicrystalline graphitic carbon nitride: Oxygen and sulfur co-doping for crystal and electronic structure modulation

Oxygen and sulfur co-doped semicrystalline graphitic carbon nitride (HGCNOS) was synthesized by a one-pot hydrothermal method and applied in visible-light photocatalytic nitrogen fixation. Remarkably, HGCNOS exhibited a higher photocatalytic activity than pristine graphitic carbon nitride (GCN). Oxygen doping caused semicrystalline structure, making exciton dissociated at the order-disorder interfaces of HGCNOS and releasing more electrons and holes. Furthermore, the conduction band position of HGCNOS was elevated by sulfur doping, promoting the reduction ability of HGCNOS. Thus, the special electronic and physicochemical structure of HGCNOS contributed to the enhanced photocatalytic activity, facilitating its application on nitrogen photofixation.

O-S co-doped semicrystalline g-C3N4 was synthesised by a simple hydrothermal method. The obtained photocatalyst had high activity and stability in visible-light photocatalytic nitrogen fixation.196