Photochemical HER activity of layered metal phospho-sulfides and -selenides

Monometallic and bimetallic layered phosphosulfides and phosphoselenides, prepared by high temperature solid state reactions, have been subjected to exfoliation to obtain few-layer materials. The photochemical HER activity of these materials has been investigated. Among the ternary MPS3, the nickel compound exhibits the highest HER activity (2.6 mmol h(-1) g(-1)), while MnPS3, ZnPS3 and CdPS3 exhibit low activity, due to their large band gaps and presence of long P-P and M-S bonds. Amongst phosphoselenides, FePSe3 shows a higher HER activity of 1.7 mmol h(-1) g(-1) than the Mn and Cd compounds. The quaternary phosphochalcogenide, Ag0.5In0.5PS3, shows a high photochemical HER activity of 1.9 mmol h(-1) g(-1).