Fig. 2: Photoelectrochemical properties of the samples.

a Photocurrent density versus potential curves of BVO-ΔOv and BVO in a 1 M borate buffer electrolyte with 0.1 M Na2SO3 (pH 9.5) under AM 1.5 G illumination. b IPCE curves at 1.23 V vs. RHE, (c) ηsep curves, (d) MS curves under dark, (e) KPFM images, (f) PL spectra, (g) Time-resolved fluorescence emission spectra, (h) UPS curves, inset: local magnification, (i) Energy level diagram of the BVO-ΔOv and BVO films. Source data are provided as a Source Data file.