Photoelectron directional transfer over a g-C3N4/CdS heterojunction modulated with WP for efficient photocatalytic hydrogen evolution

Abstract

The separation and transfer of photoelectrons is a crucial factor in the process of photocatalysis. Herein, we successfully designed and prepared WP as a cocatalyst, modified the g-C₃N₄(CN)/CdS heterojunction structure, achieved the effective separation and directional transfer of photoelectrons, and also efficient photocatalytic hydrogen evolution. In addition, the as-prepared WP–CN/CdS composite photocatalyst not only prominently improved the separation and pre-assigned transfer of photogenerated electrons, but also had abundant surface active sites, which greatly improved the photocatalytic performance of the catalyst; namely, the highest photocatalytic activity of WP–CN/CdS was achieved at 5% WP content and the highest hydrogen production rate could reach 18 238.89 μmol h⁻¹ g⁻¹, which is about 12.49 times that of pure CdS. The detailed characterization studies with SEM, TEM, XRD, XPS, DRS, UV–vis, BET, transient photocurrent, FT-IR etc. effectively supported the abovementioned results, and all the characterization results were in good agreement with each other. Moreover, a possible mechanism of the photocatalytic reaction in the WP–CN/CdS system is proposed.