| With the development of society and economy,the environment and energy problems have become more serious.Looking for clean and renewable energy has become the research hotspot.Hydrogen energy is considered to be the green energy due to its high combustion value and producing water nature,and the development and utilization of hydrogen energy has been concentrated on in the field of energy conversion.Photocatalytic and photoelectrocatalytic technology can produce hydrogen induced by solar energy.The TiO2 nanoparticles with wide band gap exhibit good photocatalytic-and photoelectrocatalytic hydrogen production activity.However,due to the low utilization of solar energy,its practical application has been limited.Therefore,fabricating new type of photocatalysts with high photocatalytic and photoelectrocatalytic efficiency under visible light irradiation has always been focused on in photocatalytic science.Metal-organic framework compounds(MOFs),due to their regulable structure,large specific surface area,and ordered porous structure displayed the wide prospect in photocatalysis.In this thesis,combining the structure and property of TiO2 and NH2-MIL-125(Ti),new composite photocatalytic(photoelectrocatalytic)materials including TiO2/NH2-MIL-125(Ti)composite particles,TiO2/NH2-MIL-125(Ti)composite films and NH2-MIL-125(Ti)@TiO2 nanotube array have been investigated.Firstly,TiO2/NH2-MIL-125(Ti)composite particles have been prepared by hydrothermal method.Some means,such as X-ray diffraction(XRD),Scanning electron microscopy(SEM),UV-Vis absorption spectroscopy,Infrared(FT-IR)spectroscopy were used to characterize their structure.The photocatlytic experiments were conducted using Rhodamine B as object under simulated sunlight irradiation.The results showed that the degradation rate of rhodamine B reached 94.6%in 45 min by TiO2/NH2-MIL-125(Ti)composite particles,which results are significantly better than that by single TiO2 and NH2-MIL-125(Ti).The as-prepared TiO2 and NH2-MIL-125(Ti)nanoparticles were spread on ITO glass by a simple coating method with different layers.The morphology,structure and electrochemical properties of these multilayer films are characterized,and their photoelectrocatalytic hydrogen generation property are also conducted using simulated sea water as electrolyte.The experimental results showed that the hydrogen production rate of the four-layered composite film was higher than that of the single TiO2 and NH2-MIL-125(Ti)films.NH2-MIL-125(Ti)@TiO2 nanotubes(TNTAs)composite films are also prepared by combining two-steps anodic oxidation process and a hydrothermal reaction.XRD,SEM,XPS,and UV-Vis diffuse reflectance spectra are used to character the composites.The photoelectrolytic hydrogen production by the NH2-MIL-125(Ti)@TNTAs films synthesized under different conditions were systematically studied.The experimental results showed that the best performance of the as-prepared composite membrane was obtained under optimum synthesis conditions.The matched band enegy between NH2-MIL-125(Ti)and TiO2 are beneficial for the transfer of photogenerated charge,and thus improve the photocatalytic and photoelectrocatalytic activities. |
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