Carbon nanosheet facilitated charge separation and transfer between molybdenum carbide and graphitic carbon nitride toward efficient photocatalytic H2 production

Abstract Interfacial manipulation of nanostructured heterojunction photocatalysts to enhance charge separation and transfer is highly desirable to achieve a high photocatalytic activity. In this work, a well-designed non-noble-metal Mo 2 C@C/g-C 3 N 4 heterostructure is constructed, in which the intercalated carbon nanosheets serve as a binder to form an excellent interfacial contact between Mo 2 C and g-C 3 N 4 . In addition, large quantities of carbon quantum dotsare found to be homogeneously embedded in the carbon nanosheets. The as-obtained Mo 2 C@C/g-C 3 N 4 hybrid exhibits a remarkably improved photocatalytic H 2 evolution rate of 52.1 μmol h −1 under visible-light irradiation (λ ≥ 420 nm) without co-catalyst, which is up to nearly 260 times higher than that of pristine g-C 3 N 4 (0.2 μmol h −1 ) under the same conditions. The significant increase in photocatalytic activity mainly results from the fast charge migration and separation between Mo 2 C and g-C 3 N 4 facilitated by the conducting carbon nanosheets as an efficient electron mediator. Moreover, the carbon quantum dots embedded in the carbon support also promotes solar energy utilization. This work highlights a feasible strategy to explore highly efficient photocatalysts via interfacial engineering on heterojunction composites.