CAJ | 학술논문

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-1．93 eV；2) O2有两种分解路径：直接分解路径(势垒为0．53 eV)和整体扩散后的分解路径(势垒为0．81 eV)；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．
채용포함색산력교정적밀도범함이론방법( DFT-D)연구료O2재Si참잡석묵희( Si-Gra)상흡부여활화．연구결과표명：1)여순정석묵희상비， Si참잡겁대적증강료석묵희대O2적흡부능력． O2적최은정흡부구형시이Side-on 모식흡부재참잡적Si적정위，형성O-Si-O삼원배．차은정흡부구형시여Si급근린적일개C형성O-Si-C-O사원배결구．량개흡부구형대응적흡부능분별위-2．40화-1．93 eV；2) O2유량충분해로경：직접분해로경(세루위0．53 eV)화정체확산후적분해로경(세루위0．81 eV)；3)분해지후적량개O원자분별흡부재Si적정위화상린탄배적량개탄원자적교위；4)전자결구분석표명흡부적O2종Si-Gra획득교다전하，종이피활화．총지， Si-Gra구유교강적최화양기환원능력，시일충잠재적량호적비금속양환원최화제．
Density functional theory including dispersion corrections ( DFT-D) is performed to study the mech-anism 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.