TiO₂光催化材料的制备及其在环境净化中的应用

【作者】 王子银；

【导师】 张征林；

【作者基本信息】 东南大学 ， 应用化学， 2003， 硕士

【摘要】 纳米TiO2光催化降解污染物是一项新兴的颇有发展前途的环境友好催化新技术，本文主要研究了纳米TiO2粒子、TiO2溶胶及膜、光催化涂料和改性光催化涂料的制备及其催化性能。采用溶胶－凝胶法制备10－30nm的二氧化钛，并研究了反应温度、催化剂、凝胶化时间及焙烧条件对粒子形成的影响。制备了均匀透明的锐钛型二氧化钛溶胶膜，并对初始浓度为200mg/L的DBS溶液的降解性能进行了研究，40分钟后降解率达到89.7％。采用均匀沉淀法制备了TiO2/SnO2复合光催化剂，溶胶－凝胶法制备了Fe3+/TiO2，并用SEM、EDS、XPS和UV－Vis漫反射光谱等技术手段对它们进行了表征。结果表明:Ti的氧化态升高，改性粒子吸收波长均明显红移。SnO2改性TiO2相比于纯TiO2，其降解次甲基蓝效率相对提高了40％左右，含Fe2％的TiO2相比于纯TiO2，其降解次甲基蓝效率相对提高了30％左右。以SnO2改性TiO2为光催化剂,丙烯酸改性有机硅树脂为粘合剂，聚氨酯为固化剂，制备了室温固化的光催化环保涂料。建立了氟苯和对氟苯甲酸的高效液相色谱分析方法。采用自制的光催化反应器，对两种催化剂的光催化活性、pH值、光强对降解反应的影响进行了研究，并对反应动力学进行了分析。结果表明：与未改性涂料相比，SnO2改性涂料的活性对氟苯的降解率由71.9％提高到90.1％, 反应表观速率常数与降解液初始浓度有关，光催化降解氟苯属于零级反应；对100ppm乙醛的降解率由69.2％提高到91.4％, 光催化降解乙醛属于一级反应。更多还原

【Abstract】 Nanosized TiO2 in photocatalytic technology of degradation environmental contaminant is a new promising catalyst. The preparation and catalysis of nanosized titanium dioxide, sol and the film of titanium dioxide、potocatalytic coating and midified potocatalytic coating were main study in this paper.nanosized titanium dioxide of 10-30nm was prepared by sol-gel techniques. The effective factors of reaction temperature,catalyst,gelatinization time and baking condition during the preparation process were studied. Aqueous transparent anatase TiO2 films were prepared and studied in degradating DBS solution with initial concentration of 200mg/L, and the degradation rate was 89.7% after 40 minutes.TiO2/SnO2 coupled photocatalyst was synthesised by uniform precipitation techniques and Fe3+/TiO2 was synthesised by sol-gel techniques. They were characterized by means of SEM、EDS、XPS and UV－Vis diffuse reflectance spectroscopy etc. The experiments showed that the oxidation state of Ti heighten and modified particles’absorption wavelength all red shift apparently.The degradation rate of SnO2/TiO2 rose relativly 40% compared with pure TiO2 and those of Fe3+/TiO2 with 30%.Photocatalytic coatings cured in room temperature were prepared by TiO2/SnO2 as photocatalyst，acryl-modified silicone resin as adhisive, polyurethane as curing catalyst. HPLC analytic method of fluorobenzene and 4-fluorobenzoic acid was established.The photocatalytic active of the two coatings were studied with self-made reactor, including the effect of pH, light intensity and reaction kinetics. The results showed that the degrdation rate of fluorobenzene by TiO2/SnO2 coating rosed from 71.9% to 90.1% compared with pure TiO2 coating. The apparent rate constant k of the photocatalytic degradation is related to the initial concentration of fluorobenzene and the reaction order is zero. The corresponding degradation rate of aldehyde with the concentration of 100ppm rosed from 69.2% to 91.4% and the reaction order is one.更多还原