S-scheme W18O49/Mn0.2Cd0.8S Heterojunction for Improved Photocatalytic Hydrogen Evolution

摘要

To deal with the energy crisis brought by economic development and solve the traditional situation where only fossil fuels can be used, we prepared S-scheme heterojunction composite photocatalyst W18O49/Mn0.2Cd0.8S for photocatalytic hydrogen production by Physical stirring method. The hydrogen production performance of composite photocatalyst W18O49/Mn0.2Cd0.8S in visible light is evaluated by a series of photocatalytic analysis and characterization methods. The results showed that the hydrogen production activity was the highest when the load ratio of W18O49 was 5 %, and the hydrogen production amount reached 268.65 mu mol (5373 mu mol h(-1) g(-1)) for 5 h, which was 2.96 times of the hydrogen production amount of pure Mn0.2Cd0.8S (90.76 mu mol). The results show that the improvement of hydrogen production performance is mainly due to the formation of S-scheme heterojunction between W18O49 and Mn0.2Cd0.8S contact interface, which promotes the consumption of ineffective electrons and holes, increases the rate of charge separation and transfer, reduces the activation energy of the catalytic reaction system, and enhances the performance of photocatalytic hydrogen production. The successful completion of this work provides a new idea for the modification of Mn0.2Cd0.8S semiconductor material and improves its application in photocatalytic hydrogen production.