Hierarchical S-Scheme Heterojunction of Red Phosphorus Nanoparticles Embedded Flower-like CeO2 Triggering Efficient Photocatalytic Hydrogen Production

Abstract

Designing heterojunctions using two semiconductors with aligned band structures is a promising strategy for solar energy-driven photocatalytic hydrogen production. Particularly, S-scheme heterojunctions exhibit significant promise for accelerating spatial separation and migration of photoexcited charge carriers while maintaining strong redox capacity. Herein, a hierarchical S-scheme composite of red phosphorus (RP) nanoparticles decorated flower-like CeO₂ (CeO₂/RP) was synthesized via the chemical vapor deposition process. Under simulated solar light irradiation, the optimized CeO₂/RP S-scheme heterojunction exhibited a highly efficient photocatalytic hydrogen production rate of 297.8 μmolꞏh⁻¹ꞏg⁻¹, which is approximately 8.8 and 5.7 times greater than that of pure CeO₂ and RP, respectively. After decoration with RP, the optical absorption of CeO₂/RP is greatly expanded to the visible light region. The effective photocatalytic performance can be primarily attributed to the presence of interfacial P―O―Ce bonds providing charge transfer pathways, as well as the development of a built-in electric field between CeO₂ and RP at the intimate interface. The photogenerated electrons follow an S-scheme mechanism, the electric field drives directional charge transfer from the conduction band (CB) of CeO₂ to the valence band (VB) of RP upon exposure to light, thus enabling the retention of photoexcited electrons and holes with higher redox potential at the CB of RP and the VB of CeO₂, respectively. This work provides a novel vision in the fabrication of S-scheme photocatalytic heterojunction systems with great photocatalytic hydrogen production performance.

1. Download: Download high-res image (102KB)
2. Download: Download full-size image