The surface morphology was observed by Zeiss
EVO MA10 scanning electron microscope (SEM) and FEI
Tecnai F20 field-emission transmission electron microscope (TEM). The elemental mapping was collected by the FEI
Tecnai F20 equipped with an energydispersive X-ray spectroscope (EDS) under STEM mode. X-ray diffraction (XRD) patterns were measured with PANalytical
X'Pert3 X-ray diffractometer. X-ray photoelectron spectroscopy (XPS) was performed by the Thermo Scientific
K-Alpha + XPS spectrometer. All binding energies were calibrated with respect to C 1 s peak at 284.8 eV. Electron paramagnetic resonance (EPR) spectra were measured with a Bruker
A300 spectrometer. Raman spectra were collected by a HORIBA iHR320 Raman microscope with a 514-nm laser. UV-visible absorption spectra were measured using Shimadzu
UV-3600 spectrophotometer with an integrated sphere. Photoluminescence (PL) spectra were analyzed using Shimadzu
RF-5301PC spectrometer. Time-resolved photoluminescence (TRPL) spectra were measured by the PicoQuant
Fluo Time 200 spectrometer coupled with a TimeHarp 260 time-correlated single-photon counting (TCSPC) system.
Peng Y., Du M., Zou X., Jia G., Permatasari Santoso S., Peng X., Niu W., Yuan M, & Hsu H.Y. (2022). Suppressing photoinduced charge recombination at the BiVO4||NiOOH junction by sandwiching an oxygen vacancy layer for efficient photoelectrochemical water oxidation. Journal of colloid and interface science, 608(Pt 2).