Graphene based catalysts for environmental and energy applications

当悬浮在水性介质中的半导体光催化剂被光照射时，所产生的带电物质（电子和空穴）行进到表面以产生能够氧化溶液中存在的有机材料的非常活跃的氧化自由基。 产生的电子-氢离子对也可以导致水分子分裂为元素氢和氧。因此，以太阳能为光源，光催化剂可以用于处理难降解的污染物，并提供清洁能源;由于光催化剂在废物处理和提供清洁能源方面的巨大潜力，开发高活性的光催化剂是最活跃的研究领域之一。 * 在过去的几年里，我们的研究工作的一个重要组成部分是使用，合成和测试二氧化钛基催化剂，用于处理耐常规生物和化学处理的难降解有机化合物。特别是，我们使用市售的TiO 2 Degussa催化剂和紫外线辐射处理来自电子加工和制药等不同行业的各种废水流中的各种有机化合物。 我们还合成了具有高光催化活性的掺杂TiO 2催化剂，使可见光可以用于该过程。* 目前提出的研究 研究了石墨烯/TiO 2纳米复合催化剂的应用 并且其可用于广泛的应用中。 石墨烯是一种非常薄的二维碳原子排列在蜂窝结构中的薄片，具有一些突出的特性，如极大的表面积，高透明度和优异的电子导电性。这些特性使它非常有吸引力 其用作电子和能量转换装置如燃料电池以及电催化剂的载体。除了催化剂的合成及其对性能的影响外，研究方案还将侧重于使用催化剂销毁微电子加工和制药工业废水沃茨中的几种化合物。将使用三种类型的石墨烯：原始石墨烯（G），氧化石墨烯（GO）和在麦吉尔等离子体加工实验室通过等离子体合成（NG）生产的氮官能化石墨烯。实验工作将集中在催化剂的活性和反应机理和中间产物的鉴定。因此，除了为加拿大两个重要的工业领域（微电子和制药）开发环境友好的工艺和设备外，拟议的研究预计将增加我们对催化材料特性，动力学和光催化反应机制的理解，从而有助于我们对催化的基本知识。最后，预计至少有四个博士， 三名硕士和几名本科生将在该计划期间接受研究培训。

When a semiconductor photocatalyst which is suspended in an aqueous medium is irradiated by light, the generated charged species (electron and holes) travel to the surface to produce very active oxidizing radicals that are capable of oxidizing organic material present in the solution. The generated e-- h+ pairs can also cause the splitting of the water molecule to elemental hydrogen and oxygen. Thus photocatalysis can be applied for cleaning up recalcitrant pollutants and provide clean energy source if solar energy is used as the light source; the development of photocatalysts with high activity is one of most active research fields because of the tremendous potential of photocatalysis in waste treatment and in providing clean energy. *In the past several years, an important part of our research effort was on the use, synthesis and testing of TiO2 based catalysts for the treatment of recalcitrant organic compounds that resist conventional biological and chemical treatment. In particular, we have used the commercially-available TiO2 Degussa catalyst and UV radiation for the treatment of various organic compounds found in various waste water streams from diverse industries such electronics processing and pharmaceutical industry. We have also synthesized doped TiO2 catalyst with high photocatalytic activity so that visible light can be used for the process. * The present proposed research is concerned with the use of graphene/TiO2 nanocomposite catalysts synthesized in our laboratory and which can be used in a wide range of applications. Graphene is a very thin sheet of two dimensional carbon atoms arranged in a honeycomb structure that has some outstanding properties such as extremely large surface area, high transparency and excellent electron conductivity. These properties make it very attractive for its use as a support for catalysts for electronic and energy conversion devices such as fuel cells as well as for photocatalysis. In addition to the synthesis of the catalyst and its effect on its properties the research program will focus on the use of the catalyst for the destruction of several compounds found in the waste waters from the microelectronics processing and pharmaceutical industries. Three types of graphene will be used: pristine graphene (G), graphene oxide (GO) and nitrogen functionalized graphene produced by plasma synthesis (NG) in the Plasma Processing Laboratory at McGill. The experimental work will focus on the activity of the catalyst and the identification of the reaction mechanism and intermediate products. Thus in addition to the development of environmentally friendly processes and devices for two important industrial areas in Canada (microelectronics and pharmaceuticals), the proposed research is expected to increase our understanding of the properties of the catalytic materials, kinetics and mechanisms of the photocatalytic reactions thus contributing to our fundamental knowledge of catalysis. Finally it is expected that at least four Ph.D., three Masters and several undergraduate students will receive training in research during the program.