Interface engineering Z-scheme Ti-Fe2O3/In2O3 photoanode for highly efficient photoelectrochemical water splitting

Exploiting interface-engineer of In2O3-based photoanode to achieve a higher charge separation efficiency could be regarded as a pivotal but challenging research in water splitting. Herein, the state-of-the-art Ti-Fe2O3/In2O3 photoanodes with different Ti4+ doping concentrations are fabricated for exploring the interface-engineering effect on PEC performance. The optimized 150Ti-Fe2O3/In2O3 photoelectrode with the rapid interfacial hole trapped (∼ 8.96 ps) and long-lived charge separation states could achieve excellent PEC performance by femtosecond time-resolved absorption spectroscopy (fs-TAS). As expected, it shows the highest photocurrent density of 2 mA/cm2 at 1.23 V vs. RHE, which is nearly 7 times higher compared with pure In2O3. Moreover, the Z-scheme mechanism could be fully confirmed by femtosecond time-resolved absorption spectroscopy (fs-TAS) and in-situ double-beam detection strategy (AM 1.5 + 405 nm). This work provides an effective and feasible strategy on designing and regulating high-efficiency composite photoanode with Z-scheme transfer mechanism.