Mo-doped BiVO₄ nanotextured pillars as efficient photoanodes for solar water splitting

We present electrospray-deposited nanotextured Mo-doped BiVO₄ pillars with improved photoelectrochemical water splitting performance. The three-dimensional nanotextured Mo-BiVO₄ pillars exhibit large interstitial spaces, which result in a high photocurrent. The doping of Mo at the optimal concentration (0.15%) results in a two-fold increase in the photocurrent density (PCD) (1.78 mA·cm⁻² at 1.2 V versus Ag/AgCl) over that of pristine BiVO₄. We attribute this increase in the PCD to increases in recombination time and in donor (electron) concentration owing to the doping with hexavalent Mo, as confirmed by Bode phase and Mott-Schottky analyses, respectively. - Highlights: • Mo-doped BiVO₄ films are formed by electrospray deposition. • Films consist of 3D nanotextured pillars, which help increase the photocurrent. • Optimal Mo doping results in two-fold increase in photocurrent density. • This is owing to an increase in the time constant for electron recombination. • Another factor responsible is the increase in donor (electron) concentration.