P-Type Boron-Doped Monolayer Graphene with Tunable Bandgap for Enhanced Photocatalytic H₂ Evolution under Visible-Light Irradiation

Graphene-based materials are considered as one of the promising photocatalysts for hydrogen production from solar-driven water splitting yet subject to zero bandgap limitation. Here, we report an efficient one-step pyrolysis for preparing p-type boron-doped monolayer graphene. Through varying the dopant content, the bandgap of the boron-doped graphene can be tuned. Moreover, a p-type conductivity behavior of the boron-doped monolayer graphene is demonstrated by the four-probe measurement and Hall effect measurement. The boron-doped graphene can service as an efficient semiconductor photocatalyst for hydrogen production from water splitting under visible-light irradiation. The optimized boron-doped graphene can deliver a high H₂ production rate of 219.3 μmol h⁻¹ g⁻¹ without any cocatalyst. The photocatalyst can be recycled at least four times without obvious activity decay and maintain high H₂ production rate of 215.3 μmol h⁻¹ g⁻¹ after 60 h reaction, indicative of excellent stability. This work may open up a new avenue for fabrication of new photocatalysts based on p-type boron-doped monolayer graphene.