Synthesis of type-II heterojunction films between ReS2 and XS2 (X = Mo,W) with high electrocatalystic activities in dye-sensitized solar cells

Type-II heterojunction films between ReS2 and XS2 (X = Mo, W) were synthesized and their electrocatalystic activities were investigated. When used as counter electrodes (CE) of DSSC, they have excellent performance and ReS2/XS2 is far better (17–26%) than that of XS2/ReS2. For the band structures of ReS2 and XS2, they form a type-II heterojunction which facilitates the electrons diffusing from XS2 to the ReS2 layer. So the electrocatalytic activity is dramatically enhanced when ReS2 is the surface layer. These results indicate a type-II heterojunction can promote the transferring of electrons to further improve the photocatalytic performance of the CE.