Dimensionality dependence study of Co-B based co-catalyst over g-C3N4 towards photocatalytic activity

Abstract The metal-semiconductor heterostructure has gained interest in the photocatalytic community due to the necessity of comprehending charge dynamics at the interface and the impact of co-catalyst dimensionality change on photocatalyst efficiency. High photocatalytic efficiency attributed to effective charge carrier separation during water splitting, a systematic in-depth study to relate reaction overpotential and interface interaction is performed over 0D-2D and 2D-2D metal-semiconductor heterojunction using density functional theory. Decoration of g−C3N4 with CoB-based clusters (4 and 8 atoms) and slab alter electronic and optical
properties. Formation of metal-semiconductor junction based on the work-function difference leads to downward band bending and generates an interfacial electric field (Eif ). Dimensionality and size of metallic co-catalyst highly change the Eif direction
which affects the migration of the charge carriers. Formation of a large number of reactive sites on either surface due to π-conjugation, and feasibility in electron migration from metal surface imparts reduction/oxidation potential to the surfaces of heterostructure. The presence of such significant properties not only shows an application of studied samples in efficient Hydrogen/Oxygen Evolution Reaction (OER/HER) but also briefs about the physics at the interface and the importance of the type of contact between co-catalyst and Photocatalyst.