Open AccessLow-cost Preparation of WO3/BiVO4 Nanocomposite Photoanodes for Photoelectrochemical Water Oxidation
Author(s) -
Syeda Qurat-ul-Ain Naqvi,
Syed Abbas Raza,
Ying Woan Soon,
Yeru Liu,
James R. Jennings
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/812/1/012007
Subject(s) - photocurrent , materials science , nanoporous , nanocomposite , electrode , dielectric spectroscopy , water splitting , chemical engineering , photoelectrochemistry , layer (electronics) , nanotechnology , catalysis , optoelectronics , electrochemistry , chemistry , photocatalysis , engineering , biochemistry
Nanostructured WO 3 electrodes coated with BiVO 4 are known to be among the best performing BiVO 4 -based photoanodes for photoelectrochemical water splitting. However, record performance is only achieved using intricate and costly electrode fabrication processes; when lower-cost, more scalable methods are used, performance drops significantly. Here, we show that a low-cost successive ionic layer adsorption and reaction method, which has received relatively little attention for the preparation of BiVO 4 , can be used to convert nanoporous WO 3 films prepared by spin coating into high-performance WO 3 /BiVO 4 photoanodes. After treatment with a cobalt phosphate co-catalyst, optimized WO 3 /BiVO 4 photoanodes can reach water oxidation photocurrent densities of up to ~3.4 mA cm -2 , with a photocurrent onset potential of ~0.56 V vs. RHE. Furthermore, an investigation by impedance spectroscopy showed that the electron diffusion length in both types of film is longer than the film thickness, which is an important requirement for an efficient nanostructured electrode. These results highlight the role that simple deposition methods such as SILAR can play in the preparation of nanocomposite photoanodes for PEC applications.