A novel 2D/2D MoSe2/SnSe heterojunction photocatalyst with large carrier transmission channel shows excellent photoelectrochemical performance

A novel 2D/2D face-to-face MoSe2/SnSe heterojunction photocatalysts have been successfully obtained from SnSe nanosheets and MoSe2 nanoplates. These MoSe2/SnSe heterojunction photocatalysts show well full spectrum absorption. The XPS results demonstrate obvious peaks shift of Sn 3d and Se 3d which reveals a binding was formed between SnSe and MoSe2 and MoSe2/SnSe heterojunction can be also confirmed by the TEM images. Pristine SnSe has a high photocurrent of 8.6 mu A/cm(2) which is much higher than many other metal sulfides and selenides such as SnS2 (1.5 mu A/cm(2)), In2S3 (1.0 mu A/cm(2)), MnS (1.6 mu A/cm(2)), MoS2 (0.73 mu A/cm(2)), MoSe2 (0.58 mu A/cm(2)), ZnSe (0.94 mu A/cm(2)) and FeSe2 (0.49 mu A/cm(2)) in our previous work. This MoSe2/SnSe heterojunction photocatalyst shows excellent photoelectrochemical performance improvement by 3 times than pristine SnSe under a compositing ratio of 5.0% MoSe2. The photocurrent of the heterojunction photocatalyst can reach 26.2 mu A/cm(2). The large improvement of photoelectrochemical performance can be ascribed to the 2D/2D face-to-face contact between SnSe nanosheets and MoSe2 nanoplates. There is carriers' transmission channel between the heterojunction which can improve the separation efficiency. The work develops a potential new energy material.