Study On The Preparation And Performance Of Titanium Dioxide-based Photocatalytic Materials

In recent years,environmental pollution has been a major challenge for humans.Semiconductor photocatalytic materials can use solar light to degrade organic pollutants in wastewater,so photocatalytic technology is used as the main means to control environment pollution.Energy shortages and environmental degradation pose a threat to human survival and sustainable development.The development of new renewable energy sources is an inevitable trend in the future.Hydrogen as a new green renewable energy,and therefore,the photocatalytic decomposition of water have been extensively studied.Titanium dioxide is widely used in the field of semiconductor photocatalysis because of its non-toxic,harmless and easy to obtain.Despite its many advantages,the defects of photocompetent carrier recombination and narrow spectral response range lead to many difficulties in catalytic degradation and application.Based on this,this topic has been discussed and researched to improve the catalytic performance of the catalyst and broaden the photoresponse range.The main research contents are as following.1.Different morphologies of titanium dioxide were prepared and their photocatalytic activity was compared.Nano-tubular,micro-spherical and nano-sheet TiO2 were prepared using different titanium sources,solvents and morphological inhibitors.The photocatalytic performance test results show that the flower-like microspheres and nano-sheet structure of TiO2 have higher photocatalytic degradation efficiency.2.Preparation of AgxAu,_x/ZnIn2S4/TiO2 photocatalyst and its photocatalytic activity.The synthesized AgxAul-x was loaded onto the surface of the ZnIn2S4lTiO2 material by photodeposition and ion exchange.HRTEM and XPS spectra show the successful synthesis and loading of AgxAu1-x alloy.After depositing gold and silver alloy,the absorption intensity and absorption range of the material in the visible light region are improved.Photocatalytic degradation experiments show that the material can completely degrade methyl orange within 80 min.The results of photolysis of hydrogen produced by water showed that the precipitation amount,yield and apparent quantum efficiency of Ag0.2Au0.8/60%ZnIn2S4/TiO2 were the highest.3.Preparation and photocatalytic activity of ZnIn2S4/TiO2 nanosheet/g-C3N4 ternary composite photocatalyst.The ZnIn2S4 microspheres were combined'with the TiO2 nanosheet/g-C3N4 composite by solvothermal method to obtain a ternary composite catalyst.The visible light response range of the composite material is further broadened and the absorption intensity is significantly enhanced.The catalytic degradation performance and photocurrent density of 60%ZnIn2S4/30%TiO2 nanosheets/g-C3N4 achieved the best results,indicating that the composite is beneficial to light absorption and photoelectron capture and separation.4.Preparation of multi-structured TiO2 microspheres/g-C3N4 composite photocatalyst and its photocatalytic activity.The high-temperature calcination method of g-C3N4 was combined with different proportions of multi-stage TiO2 microspheres,and the optimal ratio of two semiconductor composites was found by photocatalytic performance test.The material has strong photoresponsive ability in the visible and ultraviolet regions.The photocatalytic degradation ability and photocurrent test results show that the performance of 70%TiO2/g-C3N4 composite is optimal,indicating that the photoelectron separation rate is improved.