Quasi-1D SbSeI as a Photocathode for Light-driven Hydrogen Production

Abstract

This work reports the first functional implementation of SbSeI as a photocathode for photoelectrochemical hydrogen production via water splitting. SbSeI is a quasi-one-dimensional chalcohalide semiconductor that naturally forms nano/micro-ribbon structures, offering highly anisotropic charge transport and an increased interfacial surface area for photoelectrochemical reactions when properly oriented. Operating in neutral phosphate buffer, the SbSeI devices achieve a photocurrent density of 1.2 mA/cm², a half-cell solar-tohydrogen efficiency of 0.4%, and an onset potential of 0.6 V_RHE. Stable hydrogen evolution is sustained under continuous operation, demonstrating the intrinsic robustness of the material system under working conditions. A comprehensive structural, morphological, and photoelectrochemical characterization is presented, elucidating how absorber morphology and interfacial engineering govern charge transfer, efficiency, and stability. Importantly, these performances are achieved using simple device architectures, neutral electrolytes, and without reliance on scarce or noble metal nanoparticle catalysts, highlighting SbSeI as a sustainable and promising photocathode material for solar-driven hydrogen production.