O_2在Si掺杂石墨烯上吸附与活化  

The adsorption and activation of the O_2 on the Si-doped graphene

作　　者：程莹洁 张喜林[1] 薛鹏雁 徐国亮[1] 路战胜[1] 杨宗献[1] 

机构地区：[1]河南师范大学物理与电子工程学院&河南省光伏材料重点实验室,新乡453007

出　　处：《原子与分子物理学报》2015年第5期865-869,共5页Journal of Atomic and Molecular Physics

基　　金：河南师范大学"大学生创新创业训练计划"(国家级)(201310476060);国家自然科学基金(11174070;11147006);中国博士后科学基金;河南省博士后科学基金(2012M521399;2011038);河南师范大学校级青年骨干教师和博士启动基金

摘　　要：采用包含色散力校正的密度泛函理论方法(DFT-D)研究了O2在Si掺杂石墨烯(Si-Gra)上吸附与活化.研究结果表明:1)与纯净石墨烯相比,Si掺杂极大的增强了石墨烯对O2的吸附能力.O2的最稳定吸附构型是以Side-on模式吸附在掺杂的Si的顶位,形成O-Si-O三元环.次稳定吸附构型是与Si及近邻的一个C形成O-Si-C-O四元环结构.两个吸附构型对应的吸附能分别为-2.40和-1.93eV;2)O2有两种分解路径:直接分解路径(势垒为0.53eV)和整体扩散后的分解路径(势垒为0.81eV);3)分解之后的两个O原子分别吸附在Si的顶位和相邻碳环的两个碳原子的桥位;4)电子结构分析表明吸附的O2从Si-Gra获得较多电荷,从而被活化.总之,Si-Gra具有较强的催化氧气还原能力,是一种潜在的良好的非金属氧还原催化剂.Density functional theory including dispersion corrections （DFT- D） is performed to study the mechanism of O2 adsorption and activation on Si -doped graphene （Si -Gra）. It is found that： 1 ） compared with the pristine graphene, the Si doped graphene enhances the O2 adsorption. The most stable O2 adsorption is on the top of Si with the side - on configuration, resulting in the O - Si - O three member ring ; the second most stable O2 adsorption is on the bridge site of Si and its neighbor C with the O - Si - C - O four member ring. The corre- sponding adsorption energies are - 2.40 and - 1.93 eV, respectively ; 2） two kinds of decomposition paths, the direct decomposition path and diffusion path with the energy barriers of 0. 53 eV and 0. 81 eV, respectively, are presented; 3） the two atomic O （dissociated from O2 molecular） anchor on the top of Si and the bridge site of two C atoms, respectively ; 4） the activation of the O2 on the Si - Gra is from the big charge transfer between O2 and the Si -Gra support. Summarily, Si -Gra can probably serve as good and metal -free catalysts for oxygen reduction reaction.

关 键 词：Si掺杂石墨烯 O2 DFT-D 

分 类 号：O469[理学—凝聚态物理]