Layered SnSexS2−x alloys with fully chemical compositions and band gaps for photoelectrochemical water oxidation

Abstract

The water oxidation reaction plays a vital role in photoelectrochemical (PEC) water splitting, especially in a water-neutral electrolyte. In this work, photoanode SnSexS2−x alloys with fully tunable chemical compositions were synthesized by chemical vapor deposition (CVD). The modulated band gap values were also realized from 2.24 to 1.37 eV, and the corresponding optical properties were further modified in the SnSexS2−x alloys. Compared with pure SnS2 and SnSe2, especially in a 0.5 M Na2SO4 electrolyte without a sacrificial agent, the PEC performance of SnSexS2−x alloys can be obviously improved by increasing the photocurrents, which contributes to the excellent photoelectrical catalytic activity of SnSexS2−x alloys. This work provides the way to prepare environmentally friendly chalcogenide alloys for promising applications in optical and PEC water splitting.