二氧化钛及其石墨烯复合材料的合成和性能研究

发布时间：2018-02-15 19:43

本文关键词： 二氧化钛光催化活性高能面氧化石墨烯水热法　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：近几年来,随着对轻质新能源以及环境污染处理的需求,光催化材料受到了广泛的关注和研究。Ti O2因其具有廉价、无毒、化学稳定性良好等特性被广泛的用作光催化剂,它不仅在降解污水中的有机污染物和空气净化等方面有重要的应用价值,而且它在光解水制氢方面也获得了深入的研究。然而,由于二氧化钛的禁带宽度较大(锐钛矿相的禁带宽度为3.2e V,而金红石相的禁带宽度为3.0e V),因而只能吸收波长小于380nm以下的紫外光,使光催化性能受到了极大的限制。另外,当二氧化钛光催化剂吸收太阳光时,被紫外光所激发而生成的部分电子和空穴对在催化剂内部迅速复合,成为了限制光催化活性的另一个重要的因素。因而,合成较窄的禁带宽度而且还能够有效的抑制光生电子-空穴对的复合的Ti O2催化剂仍然是一个极具挑战性的科研难题。目前广泛采用的方法如在Ti O2中掺入贵金属粒子、金属氧化物、碳纳米材料,通过调节Ti O2形貌使其暴露出高活性的晶面等,有效的提高了光催化活性。本论文通过有效的控制Ti O2形貌使其暴露高能面和与石墨烯复合等方式来提高Ti O2的光催化活性。具体研究内容如下:(1)通过调控反应时间、反应物的浓度、反应釜体压强、反应温度实验变量,研究的实验条件的变化对Ti O2的形貌的影响,进一步优化实验参数,合成理想的Ti O2颗粒。(2)用水热法通过盐酸和氢氟酸的共同作用合成具有不同比例{001}和{100}晶面的二氧化钛,比较{001}和{100}晶面比例的不同对二氧化钛的光催化活性的影响,进一步确定{001}和{100}晶面的活性顺序。(3)用一步水热法和两步水热法合成了暴露高能面的二氧化钛和石墨烯复合材料,通过石墨烯导电网络增加电子迁移率,进而提高了复合结构的光催化性能。
[Abstract]:In recent years, with the demand for light new energy and environmental pollution treatment, photocatalytic materials have received extensive attention and research. TIO 2 has been widely used as photocatalyst because of its cheap, non-toxic, good chemical stability and other characteristics. It not only has important application value in degradation of organic pollutants in sewage and air purification, but also has been deeply studied in photodissociation of water for hydrogen production. Because the bandgap of titanium dioxide is larger (3.2e V for anatase phase and 3.0 EV for rutile phase), it can only absorb ultraviolet light with wavelength less than 380 nm, so the photocatalytic performance is greatly restricted. When TIO _ 2 photocatalyst absorbs sunlight, some electrons and holes generated by ultraviolet light recombine rapidly inside the catalyst, which becomes another important factor limiting photocatalytic activity. The synthesis of complex TIO _ 2 catalysts with narrow band gap and effective inhibition of photogenerated electron-hole pairs is still a very challenging research problem. At present, widely used methods such as doping noble metal particles into TIO _ 2 are very challenging. Metal oxides, carbon nanomaterials, which expose highly active crystal surfaces by adjusting the morphology of TIO 2, In this paper, the photocatalytic activity of TIO _ 2 was improved by controlling the morphology of TIO _ 2 to expose high-energy surface and recombination with graphene. The influence of the concentration of reactants, the pressure of the reactor, the experimental variables of reaction temperature and the experimental conditions studied on the morphology of TIO _ 2 was studied, and the experimental parameters were further optimized. The ideal TIO 2 particles were synthesized by hydrothermal method through the interaction of hydrochloric acid and hydrofluoric acid to synthesize titanium dioxide with different proportions of {001} and {100} crystal planes. The effects of {001} and {100} crystal planes on the photocatalytic activity of titanium dioxide were compared. The active order of {001} and {100} faces was further determined.) Titanium dioxide and graphene composites exposed to high energy surfaces were synthesized by one-step hydrothermal method and two-step hydrothermal method. The electron mobility was increased by graphene conductive network. Furthermore, the photocatalytic performance of the composite structure was improved.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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