Red Phosphorus Grafted High-Index (116) Faceted Anatase TiO₂ for Z-Scheme Photocatalytic Pure Water Splitting

Red phosphorus (RP) is an emerging visible-light-responsive photocatalyst, yet the rapid charge recombination has limited photocatalytic hydrogen production activity. In this work, a Z-scheme heterostructure with RP nanolayer coated on high-index (116) faceted anatase TiO₂ nanoparticles (TiO₂@RP) is designed and fabricated via chemical vapor deposition. Compared with pristine TiO₂ and RP, the optimized TiO₂@RP Z-scheme heterostructure exhibits a significantly boosted photocatalytic activity for pure water splitting, with hydrogen evolution rate reaching 12.9 µmol·h⁻¹, under simulated solar light irradiation. The strong interfacial interaction and staggered band alignment between (116) faceted TiO₂ and RP result in the formation of built-in electric field, which can drive the directional charge migration from the conduction band (CB) of TiO₂ to the valance band (VB) of RP under light irradiation, with photoelectrons and holes of high redox ability maintained at the CB of RP and the VB of TiO₂, respectively. This well-designed heterostructure greatly promotes photogenerated charge separation and migration via a direct Z-scheme charge transfer pathway.