| The growing energy demand over the past few decades has created energy gaps.These gaps are mainly resolved through the consumption of natural fossil fuels,but at the cost of increased greenhouse gas emissions.Therefore,the demand for clean and sustainable energy to solve the energy gap has greatly increased.Semiconductor-assisted photocatalysis technology is a "green" multidisciplinary technology that combines chemistry,physics,and materials science with chemical engineering.It can efectively use sunlight and collect it to catalyze chemical reactions and convert permanently available solar energy into beneficial Chemical energy has important applications in environmental pollution control and new energy development.In this paper,the composite catalyst C-TiO2 and the dual composite catalyst CdS/C-TiO2 were prepared by hydrothermal method and sol-gel@hydrothermal synthesis two-step method respectively.The composite catalysis was characterized by XRD,SEM,XPS,DRS The materials were characterized,and glycerol and ethanol were used as sacrificial reagents to explore the photocatalytic performance of the composite catalyst through hydrogen production experiments,and the process of hydrogen production and degradation effects of glucose simulated wastewater was explored.1.The nano-C-TiO2 composite catalyst was prepared by using hydrothermal synthesis method with glucose as the C source and tetra-n-butyl titanate Ti source.Under the visible light source,the effect of nano-C-TiO2 composite catalyst on the hydrogen production of glycerol/water system was investigated,and the stability of the catalyst under the visible light source for hydrogen production was investigated.The experimental results show that the optimal catalyst is CT-3,using glycerol as a sacrificial reagent,reacting under visible light for 6h,and the hydrogen production eficiency is the highest,which is 6.1 times that of pure TiO2.The composite catalyst C-TiO2 still has high stability after multiple cycles of photocatalytic reaction.On the basis of characterization and application,the hydrogen production mechanism of the composite catalyst C-TiO2 was explored,that is,C atoms were doped to replace the O atoms in the TiO2 lattice,thereby forming a local impurity energy in the TiO2 valence band.At the same time,the 2p orbit of C can also interact with the 3d orbit of the Ti atom,forming an independent defect energy level(Ti3+)at the bottom of the conduction band,which leads to a decrease in the band gap of the doped sample and improves the response to visible light.2.Nano-CdS/C-TiO2 dual composite catalyst was prepared by using a two-step method of sol-gel@hydrothermal synthesis using glucose,thiourea,cadmium chloride,and tetra-n-butyl titanate as raw materials.Using ethanol as a sacrificial reagent,the hydrogen production effect of nano-CdS/C-TiO2 dual composite catalyst under visible light was investigated.At the same time,the stability of hydrogen production by catalyst circulation was investigated under visible light.The experimental results show that when the CdS recombination amount is 6wt%,the dual composite catalyst has the highest hydrogen production efficiency,reaching 3353.38μmol·g-1·h-1(pure TiO2 is 245.12μmol·g-1·h-1),which is pure TiO2l3.7 times.The double composite catalyst still has good stability after a series of cycle reactions.On the basis of characterization and application,the hydrogen production mechanism of the dual composite catalyst CdS/C-TiO2 was studied,that is,the synergistic effect of the dual composite,which inhibited the combination of photogenerated electrons and holes,can effectively improve the photogenerated electron transfer efficiency and improve Catalyst hydrogen production activity.3.The dual composite catalyst CdS/C-TiO2 is used to conduct hydrogen production degradation experiment on glucose simulated wastewater:Through single factor experiments and orthogonal experiments,the optimal process conditions for hydrogen degradation of glucose simulated wastewater are determined as follows:when the catalyst dosage is 0.02g,the initial pH of the solution is 8,the reaction time is 5h,and the glucose solution concentration is 0.6g/L,this The hydrogen production efficiency under the process is 1246.18μmol·g-1·h-1,and the COD degradation rate is 37.08%. |
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