Over 14% unassisted water splitting driven by immersed perovskite/Si tandem photoanode with Ni-based catalysts

Abstract

Perovskite-based photovoltaic systems are at the forefront of innovative methods to facilitate solar fuel generation, particularly H2 generation via overall water splitting, thanks to their high photovoltage and potential for substantial solar-to-hydrogen (STH) efficiency. Despite successful encapsulation strategies employed in solar cells to enable the practical implementation of perovskite materials, the stability of perovskite-based photoelectrodes remains a significant bottleneck, restricting viable H2 production. Moreover, the intricate electrical connections and reliance on expensive noble metals hinder the pursuit of cost-effective H2 production using perovskite-based devices. In this study, we introduce a dual-absorber perovskite/Si tandem structure encapsulated with a NiFe alloy catalyst grown on Ni foil to create a monolithic photoanode. This designed photoanode yielded a photocurrent of 14.21 mA cm−2 at 1.23 V versus RHE, complemented by an onset potential of −0.5 V in an alkaline electrolyte. When combined with a cathode comprised of Ni nanowires (with a mere 46 mV overpotential at 10 mAcm−2), the system maintained a sustained overall water splitting reaction for 45 h, achieving a stand-alone STH efficiency exceeding 14%. This pioneering dual-absorber stand-alone PEC system represents a significant step towards minimizing losses and outstripping conventional tandem PV-PEC, series PV-PEC, and series PEC configurations in terms of performance, practicality, and cost-effectiveness. Show more