纳米TiO₂光催化剂的制备以及在有机废水光催化降解中的应用研究

【作者】 秦旭阳；

【导师】 关鲁雄；

【作者基本信息】 中南大学 ， 应用化学， 2004， 硕士

【摘要】 本文综述了国内外二氧化钛的研究进展，以及光催化降解染料污水的情况。纳米二氧化钛由于其独特的性能受到众多研究者的青睐，其用于光催化降解染料污水的研究也炙手可热。 本文使用水解法、水热法和溶胶—凝胶法三种方法制备了纳米二氧化钛，使用了多种检测手段，例如用X衍射确定产物的晶相，用激光粒度仪分析产物的表观粒径和粒径分布，使用透射电镜观察晶体的形貌。并且比较了三种方法制得的产物的晶相、表观粒径和粒径分布，从而确定最好的一种制备方法——溶胶—凝胶法。随后使用该法制备的纳米二氧化钛进行光催化降解实验。 我们的实验目的是为了给印染污水的光催化降解，提供参考。所以我们用常用的染料染色剂甲基蓝模拟印染污水。实验中，我们考察了众多因素对光催化降解甲基蓝溶液的影响，发现作为光催化剂的二氧化钛的量，及其类型，溶液的初始浓度和pH值等对光催化降解的影响。还发现双氧水对光催化降解的影响，由于它可以提供更多的HO自由基，导致它可以和TiO₂实现协同催化，从而大大增强了光催化降解的效果，这为以后的印染污水处理指明了方向。此外我们还发现光催化降解甲基蓝是一个拟一级反应，动力学方程是A=0.7732e^-0.2374t。 针对本实验，我们得出光催化降解甲基蓝染料，染料浓度在8mg／L，TiO₂（Made by Sol-Gel，30-40nm）0.4g／L，pH值5左右，使用450W高压汞灯作光源，配以适当的H₂O₂，可达到90％以上的光催化降解率。更多还原

【Abstract】 Research development of TiO2 home and abroad, as well as photocatalyze decomposition of printing and dyeing sewage were reviewed in the paper. Due to it’s unique performance, nanocrystaline TiO2 and it’s using in photocatalyze decomposing are being favored by more and more researches.Nanocrystaline TiO2 particles were prepared by three methods such as hydrolyze, hydrothermal and sol-gel. Many examine ways were used, for example, XRD for crystalloid, Laser granularity analyzing for granularity and distributing, TEM for appearance. These three methods were compared and the method of Sol-Gel was the best. Therefore Nanocrystaline TiO2 particles prepared by Sol-Gel was used for the experiment of Methyl blueness photocatalyze .Aim to guide the photocatalyze decomposing of printing and dyeing sewage, Methyl blueness was used to simulate polluted water .In our research we found the effect of photocatalyze decomposing were impacted by such factors as quality of TiO2, concentration and pH of Methyl blueness liquor. Because H2O2 can provide more HO, which is good for it’s cooperating photocatalyze with TiO2, the effect of photocatalyze decomposing was improved rapidly. This may provide a good direction for photocatalyze decomposing. We found that photocatalyze decomposing of Methyl blueness was one-order reaction : A=0.7732e-?2374t.The effect of Methyl blueness’ photocatalyze decomposing of over 90% was found under such condition: 8mg/L of Methyl blueness’ concentration, 0.4g/L of TiO2 (made by Sol-Gel, 30-40nm), 5 of pH, high voltage mercury light as lamp-house, proper H2O2.更多还原