Ecofriendly AgBiS₂ Nanocrystal Photoanode for Highly Efficient Visible-Light-Driven Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) hydrogen production via water splitting is a promising sustainable energy conversion method. However, most semiconductors used as photoanodes in PEC splitting exhibit several drawbacks, including ultraviolet (UV)-limited activity, toxic components, and complicated material processing. To address these issues, this study presents a photoanode design strategy for visible-light-driven PEC water splitting in aqueous Na 2 SO 4 solution using a solution-processable AgBiS 2 nanocrystal (NC) photoanode. It was observed that the characteristics of the ligand used for the AgBiS 2 NC photoanode are crucial in determining its PEC water splitting performance. Moreover, the thiol ligand-capped AgBiS 2 NC photoanode shows a higher photocurrent density ( J ph ) in both 1 sun and visible light than typical TiO 2 or Bi 2 S 3 NC photoanodes owing to its excellent electron collection ability and low interfacial charge transfer resistance. The AgBiS 2 NC photoanode emits 91% of J ph under visible and near-IR light, whereas the Bi 2 S 3 NC photoanodes exhibited a J ph of 67% under the same conditions, demonstrating the superiority of AgBiS 2 NC materials for application in highly efficient visible-light-driven PEC devices.