Revealing the role of loaded aluminum in BiVO4-based solid solutions for photocatalytic overall water splitting

One-step excitation photocatalytic overall water splitting (OWS) is an important reaction for clean energy conversion, but the efficiency is limited by the severe bulk-phase photocarrier recombination. To address this challenge, aluminum loaded tetragonal zircon BiVO 4 -based solid solution, Bi 0.5 Y 0.5 VO 4 , materials (xat%Al-BYV) were successfully prepared in this study. Photocatalytic experiments showed that the optimized xat%Al-BYV exhibited a 11-fold enhancement in OWS performance compared to the pristine BYV. Structural characterizations confirmed that Al existed in the form of γ-Al 2 O 3 and induced distortions of the VO 4 microstructure in the xat%Al-BYV via AlO 4 , which enhanced the material polarization that facilitated the separation of bulk-phase photocarrier. Photoelectrochemical tests and transient absorption spectroscopy (TAS) confirmed the optimized carrier dynamics, and TAS further elucidated the mechanism by which interfacial γ-Al 2 O 3 extracted photogenerated holes to inhibit photocarrier recombination. This work revealed the mechanism of Al loading to optimized BYV bulk-phase carrier dynamics via the synergistic effect of microstructure distortion-carrier extraction, and provided an insight for the design of other one-step excitation semiconductor materials in the future.