The Design Of The Compound Semiconductor Photocatalytic Materials And The Application Of Photocatalytic Splitting Water Into H₂

Since 1972, Japanese scientists A. Fujishima and K. Honda found that after plus partial voltage, through light irradiation TiO2 electrode, on the platinum electrode can detect the production of hydrogen in the experiment. Since then, semiconductor photocatalytic hydrogen evolution has become the research hot areas in the world. Energy and environmental issues at a global level are important topics in the 21st century. Compared with the traditional non-renewable energy sources, the hydrogen has the advantages of efficient renewable pollution-fre and has been identified as the clean energy. And the use of solar water splitting to hydrogen has been considered to be the most effective method to solve the problem of the current energy and the environment. In our study, Si/MgTiO3 heterostructures were synthesized by Mg thermal reduction of SiO2/TiO2 composite and HF-treatment. XRD, XPS, UV-Vis, SEM and TEM were used to characterize the synthesized samples.Because of the conduction band position of MgTiO3 is lower than the redox potential of H+/H2 (-0.41 V; PH=7), it has no ability to photocatalyst for hydrogen generation. Z-scheme combination of the two semiconductors MgTiO3 and Si is the optimal choice to solve the problems, the photogenerated electrons in the semiconductor with higher conduction band are used for the reductive reactions, while the holes in the semiconductor with a lower valance band are used for the oxidative reactions. The obvious advantage lies in enhancing the potential between reductive electrons and oxidative holes of the overall catalyst materials and promoting the separation of photogenerated electrons-holes pairs. Si/MgTiO3heterostructures exhibited high photocatalytic activity for H2 evolution and excellent stability from pure water without sacrificial reagen under visible light irradiation.