Papers Effect of shell-dependent variation on the photocatalytic activity of flower-like core-shell SnSe@SnO 2

Flower-like core-shell SnSe@SnO 2 was prepared by low-temperature in situ oxidation. The relationship between different oxidation times and the formation of core-shell structures of the samples was explored. The results showed that SnSe was obtained by thermal oxidation of SnO 2 in close contact with air. The size range of the flower-like core-shell structure SnSe@SnO 2 was 15 - 20 mu m. The flower-like structure was self-assembled from nanoplates with a thickness of about 200 nm. This flower-like core-shell structured SnSe@SnO 2 has a band gap of about -1.4 eV. The electrochemical characterization of the samples was analyzed for charge transfer phenomena at the junctions as well as at the interface between the shell layer and the aqueous solution. The effect of different SnO 2 shell layers on the photocatalytic degradation activity of the composites for methylene blue was evaluated. The samples with SnSe oxidized in air for 8 h showed optimal photocatalytic performance and displayed excellent photostability and reusability. In addition, O 2 was the main active species for the degradation of the organic dye methylene blue.