AUTHOR=Wang Zhi-Qiang , Wang HongJun 

TITLE=Fabrication of Cocatalyst NiO-Modified BiVO4 Composites for Enhanced Photoelectrochemical Performances

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.864143

DOI=10.3389/fchem.2022.864143

ISSN=2296-2646

ABSTRACT=In this work, NiO modified BiVO4 (BiVO4/NiO) nanocomposite was synthesized using hydrothermal and calcination method. The composite of BiVO4/NiO, further employed as a low-overpotential photoanode, was consisted of BiVO4 nanoparticles and NiO nanosheets, in which the BiVO4 nanoelectrode served as the matrix for the attachment of NiO nanosheets. Photoelectrochemical tests show that BiVO4/NiO displayed improved photoelectrochemical performance compared with pure BiVO4. The BiVO4/NiO photoanode shows a photocurrent of 1.2 mA/cm2 at 1.23 V vs RHE in a Na2SO4 electrolyte under an AM 1.5G solar simulator, which is 0.3 mA higher than pure BiVO4 photoanode. Meanwhile, the onset potential also generates a 350 mV cathodic shift. The enhanced performance of the BiVO4/NiO nanocomposite is attributed to NiO unique lamellar structure capable of providing a large number of active sites. Measurements of electrochemical impedance spectra (EIS) and the incident photon-to-current efficiency (IPCE) reveal that the enhanced PEC performances are ascribed to the increased charge carrier separation/transport and the promoted water oxidation kinetics furnished by the decoration of NiO co-catalyst.