Ultrathin Fe2P nanosheet co-catalyst CdS nanorod: The promising photocatalyst with ultrahigh photocatalytic H2 production activity

Abstract

Developing 2D ultra-thin materials as co-catalysts is an effective way to boost the photocatalytic activity of semiconductors, but it remains challenging to unveil the design principle. In this work, we prepared the ultrathin 2D Fe2P nanosheets with an average thickness of ca. 1.41 nm via the facile solvothermal method. Such 2D Fe2P nanosheets were used as co-catalyst to fabricate a 2D-1D type of Fe2P-CdS photocatalysts for visible-light-driven photocatalytic H2 evolution. Experimental and first-principles results show that the Fe2P nanosheets co-catalyst with metallic characteristics modified CdS nanorods to form a 2D-1D heterointerface with strong ionic interaction, which induces the electron density redistribution in Fe2P-CdS composite, resulting in a lower recombination rate of carriers. Moreover, Fe2P nanosheets also reduce the overpotential for hydrogen evolution, provide abundant active sites and enhance H2O adsorption, significantly promoting the release of H2. As a result, the 11 wt% Fe2P-CdS exhibited an extremely high photocatalytic performance (207.82 mmol·h−1·g−1), which is more than 78 times higher than that of the pristine CdS. This work demonstrates the potential of 2D Fe2P as a promising co-catalyst in photocatalysis and provides a useful guide on phosphide-based material designing.