Preparationof Heterogeneous Semiconductor Photoelectrodes Based On Titanium Dioxide And Study On Photoelectrochemical Water Splitting Performance

Incontemporary society,the primary energy source is met by fossil fuels,which accounts for approximately 85% of all energy.However,excessive consumption of non-renewable resource has leaded to massive emissions of carbon dioxide?CO2?,resulting in world greenhouse effect.Therefore,it becomes a challenge for people to exploit alternative green energy sources.As a kind of abundant green energy,hydrogen energy has been the main direction of energy structure improvement.Compared to fossil fuels,hydrogen has high combustion heat value and high reaction rate,and hydrogen also is a renewable energy.What's more,hydrogen can be stored in hydrogen storage material which make hydrogen can be used in many fields.Therefore,the research and development of hydrogen energy has great significance to the sustainable development of human energy.Photoelectrochemical cells is an effective device to realize the industrialized conversion of solar light to hydrogen energy by water splitting.In the photoelectrochemical cell,photoelectrode especially composed of semiconductors plays the most important role in light absorption,electron-hole pair's generation and charge transfer.As the heterojunction photoelectrode can be more efficient to promote the separation of electron-hole pairs,so the current development of the main direction of the electrode is to build novel heterojunction photoelectron.The main contents are listed as follows:First,preparation of TiO₂/Bi OCl composite photoelectrode and study ofits hydrogen production through photoelectrochemical water splittingTiO₂/Bi OCl heterostructure photoelectrode has been successfully synthesized by hydrothermal,sol-gel and chemical deposition method.According to characterization,the photoelectrochemical property of TiO₂ photoelectrodehas increased dramatically after loading Bi OCl layer.We further studied the influence of Bi OCl loading quantity on its photoelectrochemical properties.It was found that when the number of Bi OCl cycles was 60,the prepared samples exhibited the best photoelectrochemical properties.Second,preparation of TiO₂ composite photoelectrode sensitized by MoS₂ and study its hydrogen production throughphotoelectrochemical water splittingThe TiO₂/MoS₂ heterostructure photoelectrode was successfully constructed by hydrothermal and sol-gel processes.On the basis of this,we systematically studied the influence of MoS₂ on the photoelectrochemical properties of TiO₂ photoelectrode.It was found that the photocurrent intensity of MoS₂-sensitized TiO₂ photoelectrode has been greatly improved compared with that of bare TiO₂ photoelectrode.Third,preparation of TiO₂/RGO/Cu₂O composite photoelectrode and study ofits hydrogen production through photoelectrochemical water splittingThe TiO₂/RGO/Cu₂O heterostructurephotoelectrode was constructed by hydrothermal method,sol gel,spin coating and chemical deposition.The photocurrent and IPCE data show that TiO₂/RGO/Cu₂O photoelectrode exhibits the best photoelectrochemical performance when the number of Cu₂O loading cycles is 60 times.On the basis of this,we also studied the hydrogen production performance of this photoelectrode.The results show that the photoelectrode composed of TiO₂/RGO/Cu₂O has excellent hydrogen production rate.Fourth,preparation of Mg Fe2O4/RGO/V₂O₅ heterojunction and its photocatalytic propertyMg Fe2O4/RGO/V₂O₅ heterojunction nanowires were prepared by electrospinning and sol-gel method,and their photocatalytic properties were further studied.After the formation of ternary heterogeneous one-dimensional nanomaterials by loading RGO and Mg Fe2O4,the photocatalytic performance has been greatly improved on the basis of bare Mg Fe2O4.