Enhancement of photocatalytic hydrogen evolution with catalysts based on carbonized MOF-5 and g-C3N4

Abstract

The study presents enhancement of photocatalytic hydrogen generation after metal–organic framework (MOF5) carbonization at 700 °C and its utilization as a co-catalyst of graphitic carbon nitride (gCN). Thermal treatment of MOF5 affected the formation of ZnO nanoparticles which played the role of co-catalyst for H₂ evolution. Moreover, significant band-gap narrowing of MOF5 was observed, which also affected the narrowing of the hybrid band gap. The appropriate conduction band position of the carbonized MOF allowed photogenerated electron transfer from gCN to the carbonized MOF, hence, improving the separation of the charge carriers and reducing the overpotential for H₂ generation. The mechanism of the photocatalytic process was also discussed.