Photoelectrochemical And Photocatalytic H₂Evolution Of Keggin-typecesium Polyoxotungstosilicate

It is considered the most ideal way to generate hydrogen from water with solar energy. Inthis paper, CsSiW₁₂is synthesized and characterized by infrared spectroscopy （IR）, X-raydiffraction （XRD） patterns, thermal gravimetric and differential thermal analysis （TG-DTA）,UV–vis diffuse reflectance spectroscopy （UV–vis/DRS）, transmission electron microscope（TEM） and N₂adsorption/desorption analysis. The result shows that its molecular formula isCs₃HSiW₁₂O₄₀·5.5H₂O and it belongs to an Orthorhombic system. It’s spherical, the particlesize is between100and300nm and the surface area is124.6m2/g. It can strongly absorbultraviolet at200-400nm. Photoelectrochemical experiments indicate that CsSiW₁₂is a goodkind of photoelectric materials, the maximum photocurrent can reach0.1V and it has goodstability. Tne photoelectrode can be made by blending TiO₂and CsSiW₁₂together, whosephotocurrent is much higher than that produced by TiO₂alone or CsSiW₁₂alone.Theexperiment to explore the heterogeneous photocatalytic H2evolution of CsSiW₁₂:0.2g0.6%Pt/CsSiW₁₂is suspended in100mL of a20%methanol solution, and the catalyst solution isirradiated under125W Hg lamp. The average H2evolution rate is54μmol/h/g and it willincrease as the amount of catalyst increases.