Photoelectrochemical Water Splitting Using a Concentrated Solar Flux-Assisted LaFeO3 Photocathode

Abstract

Photoelectrochemical (PEC) water splitting by direct solar irradiation has been considered as a route to produce solar fuel, but the technique is impeded by limitation of the photocathode materials. Although the LaFeO3 photocathode has been identified as a potential candidate for hydrogen generation with excellent stability, lower current densities limit its PEC performance. Using solar concentration could prove to be an effective method to leverage its performance. In this study, we have developed a strategy to improve the current density of the LaFeO3 photocathode by applying concentrated solar flux. The results demonstrate that the photocurrent density follows a linear relationship with flux concentration and twofold performance enhancement with 18 times of incident flux. Furthermore, the addition of H2O2 to the electrolyte solution has significantly improved the photocurrent induced by LaFeO3 because of efficient scavenging of electrons. The fabricated LaFeO3 photocathode is translucent, and therefore, a reflector element is placed behind the substrate to redirect light back to the photocathode. The incorporation of high flux concentration, scavenger and reflector element, enhanced current density by nine times (to 0.872 mA/cm2). Our results demonstrate that the concentrated solar flux-assisted LaFeO3 photocathode will play a significant role in renewable hydrogen production, and the study will provide a direction to PEC water splitting.