Doped-nanocrystal/graphene hybrid structure for noble metal-free photocatalytic hydrogen production

在典型的半导体基光催化制氢中，贵金属助催化剂通常被用来提高载流子分离和转移的效率，而载流子的分离和转移是催化剂功能所必需的。这种贵金属部件使整个系统的经济性难以为继。为了减少对贵金属的依赖，已经研究了许多方法。在这项由国家科学基金催化与生物催化计划授予的奖项中，德克萨斯农工大学的孙东熙和郑海权基于独特的材料组合和性能提出了一种新的、更经济的战略。该研究旨在通过探索半导体催化剂的过渡金属掺杂与还原的石墨烯氧化物(RGO)形成杂化结构的协同效应，大大提高半导体基光催化剂的产氢效率。昂贵的贵金属助催化剂的作用将被丰富的过渡金属掺杂离子(如锰或铜)所取代，这些离子最近被证明可以延长半导体中的电子寿命，从而提高电荷分离和转移的效率。掺杂的纳米晶与RGO的结合提供了更有效的光催化还原反应的优势，因为RGO起到了大面积电极的作用。研究小组将开发纳米晶体/RGO复合光催化剂的结构与光催化还原关键步骤(即电荷分离、电荷转移)的效率和整体制氢效率的相关性，从而导致制氢催化剂的优化结构。拟议研究的教育部分将侧重于为本科生研究开发实验，作为NSF-REU项目和本科生研究课程参与者培训的一部分。这些经验将导致开发一种可移动的实验套件，将在当地高中现场使用，并通过RET计划对当地高中教师进行培训。这将被设计为全大学推广工作的一个新组成部分，利用德克萨斯A&A；M已经到位的传播机制。

In typical semiconductor-based photocatalysis to produce hydrogen, noble metal co-catalysts, typically Pt or Pd, are often used to enhance the efficiency of charge carrier separation and transfer that are essential for the function of catalyst. This noble metal component makes the economics of the overall system untenable. Many approaches have been investigated to reduce the dependence on noble metals. In this award from the National Science Foundation Catalysis & Biocatalysis Program, Profs. Dong Hee Son and Hae-Kwon Jeong of Texas A&M University propose a new and more economical strategy based on unique material combinations and properties. The proposed research aims to greatly enhance hydrogen production efficiency of semiconductor-based photocatalysts by exploring the synergistic effect of transition metal doping of the semiconductor catalyst combined with the formation of a hybrid structure with reduced graphene oxide (RGO). The role played by the costly noble metal co-catalyst will be replaced by abundant transition metal dopant ions (e.g., Mn or Cu), which were recently shown to extend the electron lifetime in semiconductors and thus enhancing the efficiency of charge separation and transfer. The combination of the doped nanocrystals with RGO offers the advantage of a more efficient photocatalytic reduction reaction, facilitated by the RGO functioning as the large-area electrode. The investigative team will develop the correlation of the structure of nanocrystal/RGO hybrid photocatalysts with the efficiencies of key steps of photocatalytic reduction (i.e., charge separation, charge transfer) and the overall hydrogen production efficiency, leading to an optimized structure of the catalyst for hydrogen production.The educational component of the proposed research will focus on the development of experiments for undergraduate research as a part of training the participants in a NSF-REU program and in undergraduate research classes. These experiences will lead to the development of a transportable experiment kit that will be used on site at local high schools, with training of local high school teachers through a RET Program. This will be designed as a new component of the university-wide outreach effort, exploiting the dissemination mechanisms that are already in place at Texas A&M.