【作者】 鲁文升；

【导师】 李旦振；

【作者基本信息】 福州大学 ， 物理化学， 2005， 硕士

【摘要】 本文首先采用改进的溶胶-凝胶法制备出InVO₄/TiO₂ 复合光催化剂,又在其表面修饰了Pt 形成Pt/InVO₄/TiO₂三元体系光催化剂。以乙烯为模拟污染反应物,在可见光下（λ> 450nm）,评价了催化剂的光催化性能。采用傅立叶红外（FTIR）、X 射线粉末衍射（XRD）、高分辨透射电镜（HRTEM）、荧光（PL）、N2 吸附（BET）、热重（TG/DSC）、紫外可见漫反射吸收（UV-Vis DRS）、表面光电压（SPS）、场致表面光电压（FISPS）和X 射线光电子能谱（XPS）等多种表征技术,比较分析了Pt/InVO₄/TiO₂三元体系与Pt/TiO₂和InVO₄/TiO₂二元体系的可见光的活性,探讨了催化剂具有可见光活性的原因。HRTEM 和XRD 精修数据初步说明InVO₄ 与TiO₂ 经溶胶法形成的催化剂是一种异质结型复合光催化剂;当催化剂中InVO₄的含量为0.5%,经673 K 热处理后,光催化活性最佳;化学荧光法·OH 自由基的检测证明:可见光激发下InVO₄/TiO₂ 表面产生了具有强氧化能力的活性物种（·OH）,这有利于有机污染物的降解和深度氧化;纯TiO₂在可见光照射下无光催化活性,Pt/InVO₄/TiO₂的可见光催化活性比Pt/TiO₂ 和InVO₄/TiO₂提高了近一倍;Pt/InVO₄/TiO₂催化剂的吸收带边明显红移,其可见光光吸收性能是Pt/TiO₂ 和InVO₄/TiO₂ 在相应范围内光吸收性能的叠加; Pt/InVO₄/TiO₂催化剂含有更多的锐钛矿晶型,比表面积相对TiO₂大约提高了24%;XPS 的测试表明:Pt 表面修饰后,Pt/InVO₄/TiO₂催化剂的Ti 2p的电子结合能明显增大,Cl 1s 的电子结合能降低,催化剂中含氧物种以晶格氧（O²-）、表面氧物种（Ti-O→PtCl₄）、羟基氧（OH-）和吸附氧（Oads）的形式存在,说明Pt 表面修饰后,催化剂表面确有表面态Ti-O→PtCl₄的形成。论文的创新点:首次制备了具有稳定可见光活性的InVO₄/TiO₂复合光催化剂,Pt 的表面修饰又进一步提高了催化剂的可见光的光催化活性。更多还原

【Abstract】 InVO₄/TiO₂ photocatalyst was prepared by improved sol-gel method. Pt was subsequently modified onto InVO₄/TiO₂, forming a visible-light-driven photocatalyst of Pt/InVO₄/TiO₂. Photocatalytic activity measurement was investigated under visible light irradiation （λ> 450nm）, using ethylene as a model pollutant. Photocatalyts were systematically characterized by FTIR, XRD, HRTEM, PL, BET, TG/DSC, UV-Vis DRS, SPS, FISPS and XPS et al techniques. The photocatalytic activity of Pt/InVO₄/TiO₂, InVO₄/TiO₂ and Pt/TiO₂ were compared under visible light irradiation and photocatalytic mechanism was proposed. Results of HRTEM and XRD preliminarily indicated that InVO₄/TiO₂ photocatalyst is of characteristic heterojunction structure. When the composite content of InVO₄ is up to ca. 0.5%, InVO₄/TiO₂ calcined at 673 K exhibited the highest photocatalytic activity. Terephthalic acid PL probing measurements showed a powerful oxidizing species （ OH） was photoinduced on InVO₄/TiO₂ photocatalyst irradiated by visible light, which is of vial to mineralize organic pollutants. Under visible light irradiation, no ethylene photodegradation was detected on pure TiO₂ while the degradation of ethylene on Pt/InVO₄/TiO₂ was higher at twice than that on Pt/TiO₂ or InVO₄/TiO₂. Modified by Pt and coupled of InVO₄, the band edge of Pt/InVO₄/TiO₂ shifted to visible region range, the transition of TiO₂ crystalline phase, from anatase to rutile, was suppressed efficiently and the specific surface area was increased by 24%. Analysis of XPS showed that binding energy of Ti 2p shifted to a higher energy and Cl 1s shifted to a lower energy. State of O 1s indicated that four type of containing-oxygen species, O2-, Ti-O→PtCl₄, OH-and Oads, were presented on Pt/InVO₄/TiO₂ photocatalyst. This result also made out that a new surface complex, Ti-O→PtCl₄, was formed by the stronger interaction between Pt and TiO2. This work, for the first time, introduced a visible-light-driven InVO₄/TiO₂ photocatalyst, which shows good photocatalytic activity and photostability toward ethylene degradation, and improved photocatalytic activity was then obtained by modification of Pt.更多还原