Accelerating photocatalytic hydrogen evolution of Ta2O5/g-C3N4 via nanostructure engineering and surface assembly

Abstract

Despite that several strategies have been demonstrated to be effective for improving the catalytic hydrogen evolution activity of bulky g-C3N4, the large-scale hydrogen production over g–C3N4–based photocatalysts still confronts a big challenge. Here, a two-step calcination method is presented in constructing metal oxide/two-dimensional g-C3N4, i.e., Ta2O5/2D g-C3N4 photocatalyst. Thanks to the superiority of the synthetic method, nanostructure engineering forming 2D structure, and surface assembly with another semiconductor, can be realized simultaneously, in which ultrathin structure of 2D g-C3N4 and strong interfacial coupling between two components are two important characteristics. As a result, the structure engineered Ta2O5/2D g-C3N4 induces high photocatalytic hydrogen evolution half reaction rate of ~19,000 μmol g−1 h−1 under visible light irradiation (λ > 400 nm), and an external quantum efficiency (EQE) of 25.18% and 12.48% at 405 nm and 420 nm. The high photocatalytic performance strongly demonstrates the advance of the synchronous engineering of nanostructure and construction of heterostructure with tight interface, both of which are beneficial for the fast charge separation and transfer.