Undoped and Ni-Doped CoOx Surface Modification of Porous BiVO4 Photoelectrodes for Water Oxidation
By Liu, Ya; Guo, Youhong; Schelhas, Laura T.; Li, Mingtao; Ager, Joel W.
Published in The Journal of Physical Chemistry C
2016
Abstract
Surface modification of photoanodes with oxygen evolution reaction (OER) catalysts is an effective approach to enhance water oxidation kinetics, to reduce external bias, and to improve the energy harvesting efficiency of photoelectrochemical (PEC) water oxidation. Here, the surface of porous BiVO4 photoanodes was modified by the deposition of undoped and Ni-doped CoOx via nitrogen flow assisted electrostatic spray pyrolysis. This newly developed atmospheric pressure deposition technique allows for surface coverage throughout the porous structure with thickness and composition control. PEC testing of modified BiVO4 photoanodes shows that after deposition of an undoped CoOx surface layer, the onset potential shifts negatively by ca. 420 mV and the photocurrent density reaches 2.01 mA cm