Preparation And Photocatalytic Performance Of Doped Modified TiO₂/Ti Nanotube Arrays

With the rapid development of China's economy and the rapid improvement of industrialization,energy has become an important driving force for social development.However,due to the rapid development of the global economy,fossil fuels are continuously used in large quantities,and the harm caused by the burning of fossil fuels and the shortage of energy resources are also becoming increasingly serious.Looking for renewable clean energy is the top priority in our country's social construction.With the development of China's science and technology industry and other fields,environmental problems,especially the discharge of wastewater,have also attracted extensive attention from all walks of life in China.TiO₂ nanotubes have many advantages,such as non-toxicity and good photocatalytic performance.They are considered as one of the most promising photocatalysts in the production of hydrogen from water and photocatalytic degradation of organic pollutants.However,due to its wide band gap,it can only absorb a very small band of ultraviolet light in the solar light band,and its utilization rate is very low.Therefore,high efficiency photocatalyst TiO₂/Ti nanotubes?Pt-B/TiO₂/Ti NTs?were prepared by co-modification of B doping and Pt deposition in this paper for photolysis of water to produce hydrogen.Highly efficient photocatalyst TiO₂/Ti nanotubes?B-Gd/TiO₂/Ti NTs?were prepared by co-doping non-metallic element B and rare earth element GD.They were used for photocatalytic degradation of methylene blue,and their absorption and utilization of visible light were improved accordingly.In this paper,TiO₂/Ti NTS was prepared by anodic oxidation method,and characterized and analyzed by SEM,XRD,XPS,DRS,PL,SPS and photocatalytic performance test.The effects of different preparation process conditions on the crystal structure,surface morphology and photocatalytic reaction of nanotubes were studied.The results show that under the conditions of hydrofluoric acid content of 0.4wt%,20V constant voltage anodic oxidation for 90min and heat treatment at 450?,the photolysis efficiency of B/TiO₂/Ti-15 NTs prepared with 15mmol/L of B doping is the highest.Using B/TiO₂/Ti-15 NTs as catalyst,its hydrogen production rate is 51.7?mol g^-11 h^-1.Pt was deposited on the basis of B/TiO₂/Ti-15 NTs to prepare Pt-B/TiO₂/Ti-15 NTs.under the same conditions,its hydrogen production rate was 384.9?mol g^-11 h^-1.Furthermore,the relationship between the amount of sacrificial agent methanol and the production of hydrogen by photocatalytic decomposition of water was studied,and the conclusion was drawn:the maximum amount of hydrogen was produced by photolysis of 20mL methanol.Gd/TiO₂/Ti NTs photocatalysts were prepared with different doping amounts of Gd,and characterized and analyzed by SEM,XRD,XPS,DRS,PL,SPS and photocatalytic performance tests.The results show that the photocatalytic degradation rate of Gd/TiO₂/Ti-5 NTS prepared with 5mmol/L Gd doping is 80.60%.B-Gd/TiO₂/Ti-5 NTs was prepared by co-doping with 5mmol/L Gd³⁺and 15mmol/L B³⁺,and its degradation rate was 90.21%under the same conditions.The influence factors of B-Gd/TiO₂/Ti-5 NTs photocatalysis on methylene blue degradation were analyzed.The influences of different light sources,aeration,initial concentration of solution and catalyst surface area were investigated.The results showed that using 125W high pressure mercury lamp as light source,introducing air into the solution,and choosing 1.5cm×2.5cm catalyst to degrade 5mg/L methylene blue had the highest degradation rate.The kinetic analysis of the above four factors proves that the above reactions all conform to the first-order kinetics.