Efficient Charge Carrier Transfer Route Induced by an S-Scheme α-Fe2O3/RP Heterojunction with Enhanced Photocatalytic Activity of Overall Water Splitting.

Abstract

Photocatalytic overall water splitting simultaneously generates O2 and H2; this is a potential strategy to solve the energy shortage problem. Elemental phosphorus (RP) displays ultralow visible light performance for O2 and H2 generation; thus, a novel α-Fe2O3/RP composite is designed and prepared by a low-temperature hydrothermal method via loading a trace amount of α-Fe2O3. In the experiment, the 1.5% α-Fe2O3/RP composite showed the best overall water splitting performance, which is 6.9 times that of bare RP. Through various characterization studies, the recombination rate of charges is significantly reduced. It is largely ascribed to the matched energy band structure of the two photocatalysts and the interface contact between α-Fe2O3 and RP, which efficiently separates the photocarriers through an S-scheme mode and realizes the obvious enhancement of overall water splitting performance. Moreover, α-Fe2O3/RP maintains high activity when it is persistently irradiated for 15 cycles. The research provides insight into the exploitation of low-cost, high-activity, and stable RP-based photocatalysts to achieve visible light induced overall water splitting activity to generate O2 and H2.