Photoelectrochemical properties of BiOCl microplatelets

Julie Stephenson, Veronica Celorrio, Devendra Tiwari, Simon R. Hall, David C. Green, David J. Fermín
2018 Journal of Electroanalytical Chemistry  
A B S T R A C T The photoelectrochemical properties of highly crystalline and phase-pure BiOCl microplatelets synthesised via a room temperature ionic liquid method are reported. X-ray crystallography reveals a tetragonal BiOCl phase, while high resolution electron microscopy shows sheet-like structures with a cross section of approximately 5 μm and thickness in the range of 500 nm. Diffuse reflectance spectroscopy shows a direct bandgap transition at 3.34 eV. Electrochemical measurements of
more » ... prepared BiOCl powders deposited onto fluorine-doped tin oxide electrodes show a sharp cathodic current at − 0.10 V vs RHE at pH 10, which is linked to electron injection into the conduction band edge. Photoelectrochemical measurements in the presence of Na 2 SO 3 as hole-acceptor in solution exhibit a strong potential dependence, switching from cathodic to anodic photocurrents at potentials around 0.70 V vs RHE. The positive photocurrent is associated with SO 3 2 − oxidation, while the unexpected negative photocurrents are linked to cathodic material decomposition.
doi:10.1016/j.jelechem.2017.10.024 fatcat:igxpiwwm7bdipiiudmmiowkj7a