Enhanced electron collection in a particulate LaTiO₂N photoanode assembled with an inserted ZnO nanorod array for photoelectrochemical water oxidation

Abstract

The collection of photogenerated electrons is an essential part of the photoelectrochemical process on a semiconductor photoanode, which is often a bottleneck in a particulate photoanode. Herein, by ingeniously inserting...

Growth of single-crystalline SrNbO2N micron particles and assembling of particulate photoanodes

“…34 The issues of narrow electron transport channels and high barriers formed by point contacts between semiconductor particles can be addressed by inserting ZnO nanorod arrays, which connect the photo-responsive semiconductor to the conductive substrate and form face contacts, providing wide and low-barrier electron transport channels. 28,29 The inserted ZnO nanorod arrays mainly collect photogenerated electrons from the bottom SrNbO 2 N particles in contact with them, while photogenerated electrons in the upper layers of particles suffer difficulties in transport to the conductive substrates. Consequently, the photoanode assembled from SrNbO 2 N single crystal particles with a size of around 1.1 μm exhibited better performance than those assembled from particles with sizes of around 540 nm and 750 nm.…”

“…Finally, the CoO x cocatalyst was loaded on the SrNbO 2 N/ZnONRs/AZO electrode via photoelectrodeposition from an aqueous solution of 10 mM CoSO 4 and 40 mM CH 3 COONa. 27–29 The photoanode current density was maintained at 0.004 mA cm −2 for a duration of 400 s with irradiation of visible light from a xenon lamp ( λ > 420 nm, 1500 W m −2 ). Following this, rapid annealing was performed for 4 min at 650 °C under a flow of 25 sccm NH 3 .…”