GaN/TiO2 heterostructure based anode for photoelectrochemical reactions

GaN has gained considerable interest in recent years for photocatalytic water-splitting applications due to the favorable energy position of its band edge with respect to the redox potential of many electrolytes. In addition, it has a very good chemical stability under harsh environmental conditions. Nanostructures are promising owing to their high surface-to-volume ratio. Spontaneously formed GaN NwN, taking advantage of its large surface-to-volume ratio, studied as a photoanode for photocatalytic water splitting. A heterostructure of a GaN NwN (grown using PAMBE) and p-TiO₂ (grown using atomic layer deposition) fabricated to demonstrate that a GaN NwN–based photoanode has a better photoelectrochemical response compared to that of the GaN epilayer–based photoanode. The photocurrent and incident photon to current conversion efficiency in the case of the p-TiO₂/GaN NwN was approximately 0.65 mA cm⁻² and 17%, respectively. In similar conditions, the TiO₂/GaN epilayer showed 0.24 mA cm⁻² photo current and 6% incident photon to current conversion efficiency.