Preparation And Photocatalytic Properties Of A Novel TiO 2 Photocatalytic Material

Semiconductor-based photocatalytic technology, as a novel technique, aims ateffectively coverting environmental-rfiendly and abundant solar energy into chemicaland electrical energy, and solving the global problems of energy crisis and seriousenvironment pollution to realize the eco-puriifcation and sustainable development ofsociety. Among the hundreds of photocatalysts reported in literatures, Ti02hasattracted much attention for its many advantages, such as low toxicity, high activity,chemical stable, cheap and rfee of secondary pollution. However, the wide band gap(3.2eV) of Ti〇2limits its applications on a large scale with a low quantum eiffciency.To dissolve the problems, both exploring new preparation methods and developingnovel TiC>2photocatalysts were proposed. This thesis mainly focuses in the effects ofdifferent synthetic methods and various preparation methods on the photocatalyticperformance. The present thesis is composed of the following parts:1.Microwave synthesis of Ti3+self-doped porous single-crystal anatase TiC>2for photocatalytic hydrogen evolutionTi3+self-doped porous single-crystal TiCb has been fabricated via a microwave-assisted synthesis route. TiCh was selected as titanium sources. Glacial acetic acid actsas a reacting solvent which can promote the nucleation and in-situ growth of poroussingle-crystal TiC>2without very complicated process. The HO2nanomaterials wereutilized as photocatalysts for hydrogen evolution through water splitting, indicatingthat the photocatalytic efifciency was higher than the commercial TiC>2under theirradiation with365nm LED lights. The degradation of organic dyes can also berealized under the illumination of Xe lamp. The physical and chemical properties ofTiC>2were investigated by XRD，FESEM, TEM，SAED. The effects of the microwavecondition on the photocatalytic activities were systematically studied.2.EISA synthesis of Ti3+self-doped mesoporous anatase TiC>2and itsapplication for photocatalytic oxidation of NOTi3+self-doped mesoporous anatase Ti(>2were prepared via an EISA methodinvolving water act as a solvent. Then the as-prepared materials were treated underdifferent temperatures. The materials own mesoporous structure, high BET surfacearea，and uniform pore distribution ranging rfom5.3to10.7nm. The effects ofmesoporous TiC>2with different structures on the photocatalytic NO oxidation wereinvestigated. We obtained the optimal materials with a high photocatalytic NO oxidation activity and stability. The photocatalytic degradation of organic dyes usingthese materials as photocatalysts was also investigated.3. Synthesis of hollow hexagonal prism T1O2for the photocatalytic H2evolution and degradation of organic pollutantsThe hexagonal prism precursor was prepared through a microwave-assistedmethod. TiCb, glacial acetic acid and HBF4were selected as the Ti source, solvent andmorphology oriented agent. Then the hollow hexagonal prim TiC>2materials wereobtained via calcination at different temperatures. The physical properties of Ti〇2wereinvestigated by XRD, FESEM, TEM. The effects of F127dosage on the morphology ofprecursor were studied. The hollow hexagonal prim TiC>2materials exhibited very highactivity on photocatalytic degradation of RhB under the irradiation of Xe lamp.Experimental data show that the novel TiC>2materials have potential applications forphotocatalytic H2generation.