Controllable Preparation And Photoelectric Properties Of Hollow Octahedral TiO₂with Cu₃(BTC)₂ As Template

With the development of science and technology,one of the effective solutions to deal with the global energy problems is to strengthen the development and utilization of renewable energy,especially solar energy.So the application of photoelectric materials plays an important role in this process.Ti O₂is currently one of the most widely used photoelectric materials.The photoelectric conversion efficiency of metal oxide semiconductor materials depends on their ability to absorb sunlight and inhibit photogenerated electron-hole recombination.These capabilities are closely related to the crystal structure,particle size,crystallinity,surface area and porosity of the material.On the one hand,the morphology of the material can be adjusted to control its performance;on the other hand,doping and hydrogenation modification of the material are also common methods to improve its photoelectric properties.Based on Ti O₂nanomaterials,this paper developed a new method to prepare metal-doped unique hollow structure Ti O₂nanomaterials,adjusted its morphology,and modified the composite material through hydrogenation treatment.Then ultraviolet was uesd to excite the material and the optical and electrical properties of the product under ultraviolet were tested.The effect of hydrogenation on the properties of the material could be compared.The main research contents are as follows:First,this paper designed a new method to prepare hollow octahedral composite nanomaterials.Choosing the metal organic framework(MOF)material Cu₃(BTC)₂as the sacrificial template to synthesize a Ti O₂nanoparticle film on its surface and simultaneously etch the template to make Cu ions doped into the shell,thereby obtaining a hollow octahedral Cu-doped Ti O₂in one step material.Characterization results showed that the hollow octahedron had a size of 200-500 nm,composing of Ti O₂anatase nanoparticles with a diameter of 10-20 nm,with an average thickness of30 nm.Cu ions coexisted in the form of Cu⁺and Cu²⁺and are doped into the Ti O₂crystal lattice.Then,the obtained Cu-doped Ti O₂composite material was hydrogenated by the method of hydrogen heat treatment,and the optimal hydrogenation temperature was obtained by adjusting the hydrogenation temperature comparison to be 600?.Then the heating time was adjusted at 600?and the different samples were subjected to ultraviolet light(310 nm,4W)under the photoelectric response test.It is found that as the hydrogenation time of the sample increases,the photoresponse value first increases and then decreases.The characterization showed that lattice disorder and a large number of oxygen vacancies were introduced during the hydrogenation process,and the adsorbed oxygen on the surface of the material also increased,which promoted the separation and transport of photogenerated carriers and inhibited recombination.However,hydrogenation time being too long caused the material having too much defects,which may be used as a recombination center.So it might have an adverse effect on its performance.The optimal hydrogenation time is 4h.In summary,this paper synthesized a special hollow octahedral morphology Cu-doped Ti O₂nanomaterial by template method,and effectively improved the photoelectric performance of the composite material under ultraviolet light excitation through hydrogenation treatment,and explored the corresponding hydrogenation mechanism and the best hydrogenation conditions.