In this section
@article{Zhao:2024:10.1039/d4ta02605e,
author = {Zhao, S and Jia, C and Shen, X and Li, R and Oldham, L and Moss, B and Tam, B and Pike, SD and Harrison, N and Ahmad, EA and Kafizas, A},
doi = {10.1039/d4ta02605e},
journal = {Journal of Materials Chemistry A},
title = {The aerosol-assisted chemical vapour deposition of Mo-doped BiVO4 photoanodes for solar water splitting: an experimental and computational study},
url = {http://dx.doi.org/10.1039/d4ta02605e},
year = {2024}
}
TY - JOUR
AB - BiVO4 is one of the most promising light absorbing materials for use in photoelectrochemical (PEC) water splitting devices. Although intrinsic BiVO4 suffers from poor charge carrier mobility, this can be overcome by Mo-doping. For Mo-doped BiVO4 to be applied in commercial PEC water splitting devices, scalable routes to high performance materials need to be develop. Herein, a scalable aerosol-assisted chemical vapour deposition (AA-CVD) route to high performance Mo-doped BiVO4 is developed. The materials were characterised using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-visible absorption spectroscopy, and a range of PEC tests. By studying a range of Mo-precursor doping levels (0 to 12% Mo: V), an optimum precursor doping level was found (6% Mo: V); substituting V5+ sites in the host structure as Mo6+. In PEC water oxidation the highest performing material showed an onset of photocurrent (Jon) at ~0.6 VRHE and a theoretical solar photocurrent (TSP) of ~1.79 mA.cm-2 at 1.23 VRHE and 1 sun irradiance. Importantly, Mo-doping was found to induce a phase change from monoclinic clinobisvanite (m-BiVO4), found in undoped BiVO4, to tetragonal scheelite (t-BiVO4). The effect of Mo-doping on the phase stability, structural and electronic properties was examined with all-electron hybrid exchange density functional theory (DFT) calculations. Doping into V and Bi sites at 6.25 and 12.5 at.% was performed for t-BiVO4 and m-BiVO4 phases. In accord with our observations, 6.25 at.% Mo doping into the V sites in t-BiVO4 is found to be energetically favoured over doping into m-BiVO4 (by 2.33 meV / Mo atom inserted). The computed charge density is consistent with n-doping of the lattice as Mo6+ replaces V5+ generating an occupied mid-gap state ~0.4 eV below the conduction band minimum (CBM) which is primarily of Mo-4d character. Doubling this doping level to 12.5 at.% in t-B
AU - Zhao,S
AU - Jia,C
AU - Shen,X
AU - Li,R
AU - Oldham,L
AU - Moss,B
AU - Tam,B
AU - Pike,SD
AU - Harrison,N
AU - Ahmad,EA
AU - Kafizas,A
DO - 10.1039/d4ta02605e
PY - 2024///
SN - 2050-7488
TI - The aerosol-assisted chemical vapour deposition of Mo-doped BiVO4 photoanodes for solar water splitting: an experimental and computational study
T2 - Journal of Materials Chemistry A
UR - http://dx.doi.org/10.1039/d4ta02605e
UR - http://hdl.handle.net/10044/1/114435
ER -
Dr. Andreas Kafizas
Leader - Solar Coatings Group
e-mail: a.kafizas@imperial.ac.uk
tel: +44(0)20 7594 6752
twitter: @CoatingsSolar