Effects of Prepared WSe₂ with Two Different Reductants on Its Photocatalytic Reduction Performance of Carbon Dioxide

Fossil fuel combustion and automobile exhaust emissions are the main causes of the greenhouse effect. An effective measure to solve this problem is to convert carbon dioxide into green and clean energy. Photocatalytic technology is a green technology with important application prospects in the energy and environmental fields. At present, the catalyst has some defects, such as specific surface area is lower, the photoelectric-hole pair recombination rate is fast and the quantum efficiency is low. Therefore, effective photocatalysts have become the focus of researchers. In the paper, WSe₂ was successfully prepared by the hydrothermal reaction using two different reductants and solvents, and the XRD, UV-Vis DRS, N₂ adsorption-desorption tests are adopted for characterization of prepared sample. The XRD, UV-Vis DRS and BET characterization results show that the WSe₂ samples prepared with two reductants both contain pure-phase WSe₂, and the location distribution of main diffraction peaks is consistent with that of hexagonal WSe₂ (JCPDS card, PDF#38-1388); the prepared WSe₂ presents photo response within the range of 200-700nm, but compared with WSe₂ (NaBH₄), the light absorption intensity of WSe₂ (N₂H₄.H₂O) is significantly enhanced; compared with WSe₂ (NaBH₄), the specific surface area of WSe₂ (N₂H₄.H₂O) is bigger, which are 3.4 m^2.g⁻¹ and 3.0 m² g⁻¹, respectively. After photocatalytic reaction for 12h with the catalyst of two different WSe₂ (N₂H₄.H₂O) and WSe₂ (NaBH₄), WSe₂ (N₂H₄.H₂O) shows great photocatalytic activity, and the overall yields of CH₃OH are 327.13 μmol g⁻¹cat and 46.32 μmol g⁻¹cat, respectively.