Designing Charge Transfer Route at the Interface between WP Nanoparticle and g-C3N4 for Highly Enhanced Photocatalytic CO2 Reduction Reaction

Abstract Developing metallic co-catalysts is an effective way to enhance the photocatalytic activity of semiconductor by forming the Schottky junction, but it remains challenging to unveil the design principle. Herein, a novel nanocomposite is prepared by coupling ultra-small WP nanoparticles embedded on N-doped carbon (WP NC) with 2D graphitic C3N4 (g-C3N4). The WP NC and g-C3N4 form an intimate interface via PN chemical bonds at atomic level, which facilitates the flow of photoexcited electrons from g-C3N4 to WP NC. Moreover, the Schottky junction formed at the interface can prevent the charge-carrier recombination in the WP NC/g-C3N4 composite and thus significantly enhance the photocatalytic CO production rate from 29 (bare g-C3N4) to 376 μmol g−1 h−1. As the first example of WP applied on the photocatalytic CO2 reduction, this work demonstrates the potential of metallic WP as a co-catalyst in photocatalysis and provides a useful guide on the phosphide-based material designing.