导　　师： 孙晓君

学科专业： 081704

授予学位： 硕士

作　　者： ;

机构地区： 哈尔滨理工大学

摘　　要： 在半导体光催化剂中,TiO2因其光催化活性较高、水中稳定性好、无毒,价廉而得到广泛研究。但TiO2带隙能量较大/(Eg =3.2 eV/) ,故其只能在紫外光区显现出光化学活性。为了更有效地利用太阳光,研究并开发出在可见光下具有高效光催化活性的催化剂具有重要的理论意义和现实意义。 本论文针对传统的TiO2等光催化剂禁带能隙较宽,只能在紫外光范围内产生光催化活性的问题,在深入分析半导体光催化剂光催化机理的基础上,提出制备一种带隙能较低的新型光催化剂TaON。本论文采用高温气固相反应,以Ta2O5为原料,通过氮化反应制备TaON。并采用X-射线衍射/(XRD/)分析、X-射线光电子能谱/(XPS/)分析、紫外-可见/(UV-VIS/)漫反射光谱分析等测试手段对所制备的光催化剂进行了表征,重点考察反应温度、反应时间、氨气流量等因素对催化剂结构及组成的影响。对不同反应条件下所制样品进行XRD测试分析,结果表明:在反应温度为850℃,反应时间为10h,氨气流量为100 ml//min条件下制备样品的X-射线衍射峰与TaON的衍射峰一致;对各样品进行的XPS测试分析表明:通过氮化反应Ta2O5的Ta4f7//2结合能峰向结合能小的方向移动,形成了共价性较高的Ta-N键,并且,在上述反应条件下得到了非化学计量比组成为TaO1.2N0.8的样品,由此确定了催化剂的最佳制备条件。为了考察所制备催化剂的光谱响应范围,选取了在最佳反应条件下制备的催化剂样品进行了紫外-可见/(UV-VIS/)漫反射光谱测试,测试结果表明:TaON的光谱相应范围可拓宽至500nm,证明TaON具有可见光响应能力。 此外,在模拟太阳光下,研究了光催化剂TaON光催化降解苯酚的催化活性,采用4-氨基安替吡啉分光光度法测定溶液中苯酚的浓度并计算苯酚的降解率,考察了光催化反应中催化剂用量、反应时间、溶液pH值、催化剂制备条件� TiO2 has been studied for many years because of its higher photocatalytic activity,higher stability,nontoxicity and low-cost.However, TiO2 may show photocatalytic activity only by irradiation of ultra violet/(UV/)light for its wide band gap/(Eg=3.2eV/). It is vital for study on photocatalyst with the highest photocatalytic activity by visible-light in order to apply sun-light effectively. Considering the problem that the band gap energy of traditional photocatalysts, such as TiO2,is so big that they can only show their catalytic activity in ultra violet /(UV/) light, a new kind of photocatalyst TaON with small band gap energy has been prepared, which is based on the theory of the catalysis of semi-conductor photocatalysts. TaON has been synthesized with Ta2O5 as the raw material and being nitrified by gas-solid reaction under high temperature.In addition, XRD, XPS, and UV-VIS analysis are made for prepared photocatalysts. The effects of the reaction temperature, time, and the flux of ammonia gas on the structure and composition of prepared catalysts are investigated. The result of the analysis shows that the XRD pattern of the prepared sample, which is prepared when the reaction temperature is 850℃, the reaction time is 10 hours and the flux of ammonia gas is 100 ml//min, is the same as that of TaON. The result of XPS analysis of the samples that has been made in different reaction condition indicates that the combined energy peaks of Ta4f 7//2 of Ta2O5 shifts to the lower combined energy. In addition, the combined energy peaks of N1s has been found in the XPS spectra, indicating Ta-N bond with lower energy is formed. Non-stoichiometric sample,TaO1.2N0.8 , is formed under the above reaction condition. Thus the most optimal technical parameter of synthesizing the catalyst has been determined as follows: reaction temprature 850℃, reaction time 10 h, the flow rate of ammonia gas 100ml//min. In order to investigate the responding area to the light, UV-VIS analysis has been made for the sample which has b

关 键 词： 光催化剂 可见光 光催化降解 苯酚

领　　域： [环境科学与工程]