酞菁配合物-TiO₂/SnO₂复合材料的制备及脱硫性能研究

【作者】 张改；

【导师】 赵建社；

【作者基本信息】 西北大学 ， 材料化学， 2012， 博士

【摘要】 酞菁配合物是一种化学性质稳定且具有优异光学性能的染料,在光催化领域受到了人们越来越多的关注。酞菁配合物敏化半导体光化学氧化法是一种更加有效的深度氧化脱硫的途径。本文在对国内外文献研究的基础上,采用改进的固相熔融法合成具有代表性结构的两类酞菁配合物,并采用溶胶凝胶-水热法将酞菁配合物键合在半导体材料Ti02和Sn02表面,形成酞菁配合物-Ti02和酞菁配合物-SnO2光敏催化剂。在紫外和可见光照射下利用制备的光催化剂催化氧化模拟燃油中的噻吩,探讨复合材料结构和光催化性能的关系,总结光催化氧化脱硫反应的特点和规律,为酞菁配合物-Ti02(Sn02)光催化脱硫剂的应用与实践提供有益的借鉴和启示。本论文内容如下：1.选取酞菁配合物和四羧基取代酞菁配合物作为敏化剂。采用改进的固相熔融法制备得到无取代酞菁配合物MPc四羧基取代酞菁配合物MPcTc(M=Mn(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ));并对所得到的酞菁配合物进行元素分析、红外光谱和紫外光谱等表征。2.采用溶胶凝胶-水热法合成酞菁配合物敏化二氧化钛光催化氧化脱硫剂。以酞菁配合物和四羧基取代酞菁配合物作为敏化剂,通过改变反应温度、摩尔比以及水热反应时间来制备脱硫催化剂两类12种(MPc-TiO2复合物和MPcTc-TiO2复合物,其中M=Mn(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)),得到催化剂制备的最佳反应条件：表观摩尔比1：100,水热反应温度200℃,反应时间为4h。并对所得催化剂进行红外光谱、XRD、SEM、XPS以及荧光光谱等测试。红外吸收光谱中特征吸收峰的变化,荧光光谱中荧光淬灭现象的出现,以及光电子能谱中主要元素结合能的较大变化都说明复合材料中存在强烈的化学作用。3.采用溶胶凝胶-水热法合成染料敏化二氧化锡光催化氧化脱硫剂。以酞菁配合物和四羧基取代酞菁配合物作为敏化剂,在相同条件下制备了脱硫催化剂两类12种(MPc-SnO2复合物和MPcTc-SnO2复合物,其中M=Mn(Ⅱ)、Fe(Ⅱ)、 Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)).对所得催化剂进行红外光谱、XRD、SEM、XPS以及荧光等测试。红外吸收光谱中特征吸收峰的变化,荧光光谱中荧光淬灭现象的出现,以及光电子能谱中主要元素结合能的较大变化都说明复合材料中存在强烈的化学作用。4.通过紫外光和可见光降解模拟燃油中噻吩的实验研究了酞菁配合物-TiO2催化剂的脱硫性能,研究了影响光催化降解的主要因素,得到光催化降解反应的最佳条件：催化剂加入量均为0.10g·100L-1,空气流速100mL·min-1。并对紫外光催化降解产物进行了研究,发现氧化产物主要为CO2、砜和SO42-。结果表明,所制备的催化剂在鼓空气的条件下3h燃油中的噻吩降解转化率可达到90%以上,效果良好。5.在相同条件下研究了酞菁配合物-SnO2催化剂的脱硫性能。结果显示TiO2的光催化性能要明显高于SnO2。在紫外光照射180min后,酞菁配合物敏化半导体复合光催化氧化剂相对于纯半导体催化剂具有较好的光催化效果。但敏化剂为羧基取代酞菁配合物时紫外光照射下催化效果略低于无取代酞菁配合物。在300w碘钨灯照射90min后,不管半导体是TiO2还是SnO2,羧基取代酞菁配合物敏化的半导体复合催化剂光催化性能都优于无取代酞菁配合物。在分析实验结果的基础上,对光催化反应机理进行数理论证,确定光催化氧化噻吩为表观一级动力学反应,动力学方程为ln(C0/Ct)=Kt+A。更多还原

【Abstract】 Metal phthalocyanine has been given more and more attention in the field of photo catalysis because of the stable chemical properties and the excellent optical properties.The photochemical oxidation technology of dye-sensitized semiconductor is a promising way for deep oxidative desulfurization. In this paper, a facile developed ’sol-gel hydrothermal” technique was used to synthesize metal phthalocyanine (MPc)-semiconductor (TiO2or SnO2) catalysts for photodegradation of thiophene. The photocatalytic properties were evaluated by the degradation of thiophene in the UV and visible light irradiation conditions.The main work in this paper is as follows:1. The metal phthalocyanine (MPc) and four carboxyl substituted metal phthalocyanine (MPcTc)(M=Mn(Ⅱ), Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ))have been synthesized by the method of solid phase and characterized by elemental analysis, infrared spectroscopy and ultraviolet spectroscopy.2. The composites of dye-sensitized TiO2have been synthesized by the method of sol-gel hydrothermal technique and characterized by IR, XRD spectra, SEM, XPS and fluorescence spectroscopy. The composites were two types of the MPc-TiO2catalyst and MPcTc-TiO2catalyst, which M=Mn(Ⅱ)、Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、 Cu(Ⅱ)、Zn(Ⅱ). The characteristic absorption peaks changing of the infrared absorption spectrum, fluorescence quenching phenomenon of the fluorescence spectroscopy and larger changes for major element binding energy of photo electron spectroscopy show the presence of strong chemical bonds in the composites.3. The composites of dye-sensitized SnO2have been synthesized by the method of sol-gel hydrothermal technique and characterized by Infrared spectroscopy(IR), Scanning electron microscopy(SEM), X-ray diffraction(XRD), X-ray Photoelectron spectroscopy(XPS) and fluorescence spectroscopy. The composites were two types of the MPc-SnO2catalyst and MPcTc-SnO2catalyst, which M=Mn(Ⅱ)、Fe(Ⅱ)、 Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ). The characteristic absorption peaks changing of the infrared absorption spectrum, fluorescence quenching phenomenon of the fluorescence spectroscopy and larger changes for major element binding energy of photoelectron spectroscopy show the presence of strong chemical bonds in the composites.4. The photocatalytic properties of phthalocyanines-TiO2were tested by the degradation effects of thiophene under the UV and visible light irradiation conditions. Studied the main factors of the photocatalytic degradation, the best condition for the photocatalytic degradation is as follows:catalysts are0.10g·100L-1and air flow rate of100mL·min-1. The results indicate that the catalysts are effective for the degradation ofthiophene in the fuel under the conditions of the drum air.5. The photocatalytic properties of phthalocyanines-SnO2were tested under the same condition. The results showed that the photocatalytic properties of TiO2to be significantly higher than that of SnO2. After UV irradiation180min, photocatalytic effect of phthalocyanine sensitized semiconductor composite are higher than that of pure semiconductor catalyst. The carboxyl substituted phthalocyanine complexes sensitized semiconductor composite have better photocatalytic effect at300w tungsten lamp irradiation90min regardless of the semiconductor TiO2or of SnO2. The kinetic equation was simulated in term of the analysis of experimental results. The process of all photocatalytic reaction conformed to the kinetics of first order reaction. The dynamic equation is In (Co/Ct)=Kt+A.更多还原