High-gravity-assisted engineering of Ni2P/g-C3N4 nanocomposites with enhanced photocatalytic performance

Abstract Graphitic carbon nitride (g-C3N4) with transition metal phosphides has been studied extensively as potential photocatalysts for hydrogen evolution. However, in-situ approaches to realize intimate interfacial contacts have rarely been reported. In this study, Ni2P nanoparticles-decorated g-C3N4 photocatalysts were prepared via liquid exfoliation of g-C3N4 followed by in-situ loading of Ni2P nanoparticles in a rotating packed bed (RPB) reactor. The optimized Ni2P/g-C3N4 exhibits high performance in visible-light-driven (λ > 420 nm) hydrogen evolution (∼561 μmol g-1 h-1), which is 103 times higher than that of pristine g-C3N4. The superior photocatalytic performance and durability originate from the robust interfacial structure. Therefore, a Z-scheme route with enhanced transfer of photoinduced electron was proposed, and Ni2P/g-C3N4 composites with smaller bandgaps than those of g-C3N4 were realized. Due to the intensified mass transfer and mixing of RPB reactor, the adsorption and nucleation processes of Ni2P on g-C3N4 were enhanced, enabling scalable solar light-driven H2 production.