In this section
@article{Ma:2016:10.1002/adfm.201600711,
author = {Ma, Y and Kafizas, A and Pendlebury, SR and Le, Formal F and Durrant, JR},
doi = {10.1002/adfm.201600711},
journal = {Advanced Functional Materials},
pages = {4951--4960},
title = {Photoinduced Absorption Spectroscopy of CoPi on BiVO4: The Function of CoPi during Water Oxidation},
url = {http://dx.doi.org/10.1002/adfm.201600711},
volume = {26},
year = {2016}
}
TY - JOUR
AB - This paper employs photoinduced absorption and electrochemical techniques to analyze the charge carrier dynamics that drive photoelectrochemical water oxidation on bismuth vanadate (BiVO4), both with and without cobalt phosphate (CoPi) co-catalyst. These results are correlated with spectroelectrochemical measurements of CoII oxidation to CoIII in a CoPi/FTO (fluorine doped tin oxide) electrode during dark electrocatalytic water oxidation. Electrocatalytic water oxidation exhibits a non-linear dependence on CoIII density, with a sharp onset at 1 × 1017 CoIII cm−2. These results are compared quantitatively with the degree of CoPi oxidation observed under conditions of photoinduced water oxidation on CoPi–BiVO4 photoanodes. For the CoPi–BiVO4 photoanodes studied herein, ≤5% of water oxidation proceeds from CoPi sites, making the BiVO4 surface the predominant water oxidation site. This study highlights two key factors that limit the ability of CoPi to improve the catalytic performance of BiVO4: 1) the kinetics of hole transfer from the BiVO4 to the CoPi layer are too slow to effectively compete with direct water oxidation from BiVO4; 2) the slow water oxidation kinetics of CoPi result in a large accumulation of CoIII states, causing an increase in recombination. Addressing these factors will be essential for improving the performance of CoPi on photoanodes for solar-driven water oxidation.
AU - Ma,Y
AU - Kafizas,A
AU - Pendlebury,SR
AU - Le,Formal F
AU - Durrant,JR
DO - 10.1002/adfm.201600711
EP - 4960
PY - 2016///
SN - 1616-301X
SP - 4951
TI - Photoinduced Absorption Spectroscopy of CoPi on BiVO4: The Function of CoPi during Water Oxidation
T2 - Advanced Functional Materials
UR - http://dx.doi.org/10.1002/adfm.201600711
UR - http://hdl.handle.net/10044/1/39302
VL - 26
ER -
Dr. Andreas Kafizas
Leader - Solar Coatings Group
e-mail: a.kafizas@imperial.ac.uk
tel: +44(0)20 7594 6752
twitter: @CoatingsSolar