Rational Design and Fabrication of Noble‐metal‐free Ni_xP Cocatalyst Embedded 3D <i>N</i>‐TiO₂/g‐C₃N₄ Heterojunctions with Enhanced Photocatalytic Hydrogen Evolution

Abstract

Abstract Developing low‐cost and efficient noble‐metal‐free photocatalytic materials is crucial for the hydrogen production through water splitting. Herein, N ‐TiO 2 /g‐C 3 N 4 heterostructure loaded with a noble‐metal‐free Ni x P cocatalyst was prepared by the combination of ammonia etching and photo‐reduction deposition method. The results demonstrated that N‐doped TiO 2 ( N ‐TiO 2 ) nanosheets were formed and stood upright on the surfaces of g‐C 3 N 4 nanosheets, forming a 3D structure. The ternary hybridization of N ‐TiO 2 /g‐C 3 N 4 @Ni x P hierarchical nanostructure was a promising strategy to achieve highly efficient photocatalytic H 2 evolution, showing an optimized hydrogen evolution rate of 5438 μmol g −1 ⋅h −1 using 300 W Xe lamp as irradiation source, which was 7.5 times higher than that of N ‐TiO 2 /g‐C 3 N 4 . The enhanced photocatalytic activity was ascribed to the combined effects of Ni x P cocatalyst loading and the formation of the intimate nanoheterojunctions between TiO 2 nanosheets and g‐C 3 N 4 nanosheets, which were favorable for promoting charge transfer. The present work would provide a novel facile preparation and practical application of many other noble‐metal‐free metal phosphides as a highly efficient cocatalyst for hydrogen production through water splitting.