The Photoelectrochemical Response of PbCrO4 Thin Film Fabricated Using Pechini Method: The Effect of Nitrate Decomposition in Precursor Solution

Abstract

PbCrO4 is one of the metal-oxide semiconductors that can be utilized for photoelectrochemical water oxidation. The Pechini method was employed to fabricate a PbCrO4 thin film photoanode, and the properties of the thin film were found to be dependent on the precursor heating temperature. Precursor heating enhanced the complexation between the metal ion and citric acid and the decomposition of metal nitrate in the Pechini precursor solution, leading to the fine morphology of the film. As the precursor heating temperature increased, the grain size of the film decreased, which lowered the photoresponse for precursor heating temperatures above 80 °C. Meanwhile, at a low precursor heating temperature, the presence of the Urbach tail was confirmed via UV–vis absorption spectroscopy. It can act as a trap, capturing the charge carrier, and leading to the decrease in the photoresponse of the PbCrO4 thin film. Consequently, the photoactivity of the PbCrO4 thin film toward water oxidation was maximized for a precursor heating temperature of 80 °C. However, the performance of the PbCrO4 photoanode degraded during water oxidation, regardless of the precursor heating temperature.