Ca‐Doped PrFeO₃ Photocathodes with Enhanced Photoelectrochemical Activity

Abstract

Perovskite oxides, renowned for their adaptable structure and optoelectronic characteristics, hold significant potential for applications in catalysis and photoelectrochemical processes. This research investigates the preparation of praseodymium iron oxide (PrFeO3) by spin coating and the impact of incorporating a calcium (Ca) dopant on its photoelectrochemical efficacy as photocathodes. Spin coating of a polymer containing sol‐gel yielded thin films with uniform morphology and porosity, facilitating effective semiconductor/electrolyte interactions, as characterised by scanning electron microscopy analyses. Evaluation of transient photocurrent responses revealed that introducing Ca at a 5 at% doping level significantly enhanced the photoelectrochemical activity of PrFeO3, resulting in an optimal photocurrent of ‐124 µA cm‐2 at +0.43 VRHE under simulated sunlight conditions. This enhancement was accompanied by an incident photon‐to‐current efficiency of 3.8% at +0.43 VRHE and 350 nm, along with an onset potential of +1.1 VRHE. Ultraviolet and visible spectroscopy analyses indicated an increase in light absorption capabilities in the Ca‐doped films and a noticeable reduction in bandgap compared to the undoped counterparts, further supported by incident photon‐to‐current efficiency measurements. The findings underscore the significant role of dopants in augmenting the photocurrent performance of stable perovskite oxides, highlighting their potential in advancing photon conversion technologies.This article is protected by copyright. All rights reserved.