Ecofriendly AgBiS₂ Nanocrystal Photoanode\nfor Highly Efficient Visible-Light-Driven Photoelectrochemical Water\nSplitting

Abstract

Photoelectrochemical (PEC) hydrogen production via water\nsplitting\nis a promising sustainable energy conversion method. However, most\nsemiconductors used as photoanodes in PEC splitting exhibit several\ndrawbacks, including ultraviolet (UV)-limited activity, toxic components,\nand complicated material processing. To address these issues, this\nstudy presents a photoanode design strategy for visible-light-driven\nPEC water splitting in aqueous Na₂SO₄ solution\nusing a solution-processable AgBiS₂ nanocrystal (NC) photoanode.\nIt was observed that the characteristics of the ligand used for the\nAgBiS₂ NC photoanode are crucial in determining its PEC\nwater splitting performance. Moreover, the thiol ligand-capped AgBiS₂ NC photoanode shows a higher photocurrent density (<i>J</i>_ph) in both 1 sun and visible light than typical\nTiO₂ or Bi₂S₃ NC photoanodes owing\nto its excellent electron collection ability and low interfacial charge\ntransfer resistance. The AgBiS₂ NC photoanode emits 91%\nof <i>J</i>_ph under visible and near-IR light,\nwhereas the Bi₂S₃ NC photoanodes exhibited a <i>J</i>_ph of 67% under the same conditions, demonstrating\nthe superiority of AgBiS₂ NC materials for application\nin highly efficient visible-light-driven PEC devices.