Tuning charge transfer between size-controlled Pt cluster and N vacancy engineered ultrathin g-C3N4 for efficient photocatalytic hydrogen evolution

Rational design and development of metal-cluster co-catalysts with regulated charge transfer interface is an effective strategy to fabricate highly active photocatalysis. Here, Pt clusters are elaborately incorporated onto N vacancy engineered ultrathin g-C3N4 (vUCN) by a facile photo-deposition method. The targeted vUCN-300Pt with cluster size of 1.1 nm and dispersion density of 104 μg m−2 exhibits an optimal photocatalytic rate of 862.4 μmol h−1 g−1, which is approximate 40 times and 5.3 times higher than that of pristine g-C3N4 and vUCN. The inherent reason for the superior property lies on the efficient electron transfer pathway, in which electrons are effectively migrated to the surface assisted by the ultrathin structure and appropriate N vacancies, and subsequently directed towards the neighboring Pt cluster. Additionally, the light absorption ability and the proton reduction kinetics are both promoted under the collaborative optimization of the band-gap structure by Pt cluster and vUCN. Afterwards the Pt site with reduced Gibbs free energy could serve as a highly active medium for combining H* and the transferred electron to achieve efficient H2 evolution. The relevance of these findings provides useful guideline for tuning the reactive metal-support interaction (RMSI) between Pt cluster and g-C3N4-based catalysts.