AUTHOR=Wang Zhi-Qiang , Wang HongJun 

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

JOURNAL=Frontiers in Chemistry

VOLUME=10

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=<p>In this work, NiO modified BiVO<sub>4</sub> (BiVO<sub>4</sub>/NiO) nanocomposite was synthesized using hydrothermal and calcination method. The composite of BiVO<sub>4</sub>/NiO, further employed as a low-overpotential photoanode, was consisted of BiVO<sub>4</sub> nanoparticles and NiO nanosheets, in which the BiVO<sub>4</sub> nanoelectrode served as the matrix for the attachment of NiO nanosheets. Photoelectrochemical (PEC) tests show that BiVO<sub>4</sub>/NiO displayed improved PEC performance compared with pure BiVO<sub>4</sub>. The BiVO<sub>4</sub>/NiO photoanode delivers a photocurrent density of 1.2 mA/cm<sup>2</sup> at 1.23 V vs. RHE in a Na<sub>2</sub>SO<sub>4</sub> electrolyte under an AM 1.5G solar simulator, which is 0.3 mA/cm<sup>2</sup> higher than pure BiVO<sub>4</sub> photoanode. Meanwhile, the onset potential also generates a 350 mV cathodic shift. The enhanced performance of the BiVO<sub>4</sub>/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) illustrate that the enhanced PEC activities are ascribed to the improved charge carrier separation/transport and the promoted water oxidation kinetics furnished by the decoration of NiO cocatalyst.</p>