MOF-templated in situ fabrication of surface-modified Ni/graphitic carbon nitride with enhanced photocatalytic hydrogen evolution

Abstract

The fabrication of noble-metal-free and low-cost photocatalysts with high efficiency has been under increasing demand for solar energy usage and conversion. In this work, a series of surface-modified Ni/graphitic carbon nitride (g-C₃N₄) photocatalysts derived from metal–organic frameworks (MOFs) were synthesized by the in situ pyrolysis of Ni-based benzenedicarboxylic acid Ni₂(BDC)₂ in the presence of graphitic carbon nitride under Ar protection. The as-prepared samples displayed highly efficient H₂ evolution under visible-light irradiation, with a maximum H₂ production rate of 2989.5 μmol g⁻¹ h⁻¹, which was about 22.1 times higher than the value of carbon nitride (135.2 μmol g⁻¹ h⁻¹). This exceptionally enhanced photocatalytic activity originated from the tight bonding between the Ni-based cocatalyst and g-C₃N₄ as well as fast and efficient electron transfer with the help of conductive carbon loaded on the surface of the Ni species during Ni₂(BDC)₂ pyrolysis.