三维石墨烯基B-N-Fe/Co-G材料的制备及其氧还原催化性能研究

采用脲、硼酸、硝酸铁、硝酸钴分别作为N、B、Fe、Co源,与GO(氧化石墨烯)通过快速冷冻干燥与热解法,制得了三维石墨烯基B-N-Fe/Co-G催化材料,并对其结构和性能进行了测试和表征,研究其氧还原的活性物质与活性点。透射电子显微镜(TEM)、扫描电子显微镜(SEM)、拉曼光谱(Raman)、X射线衍射(XRD)及X射线光电子能谱(XPS)结果显示,所制得掺杂石墨烯表面褶皱呈三维孔洞结构,掺杂原子N、B、Fe、Co均匀掺杂于石墨烯中。通过循环伏安法(CV)、线性扫描伏安法(LSV)等手段对三维石墨烯基B-N-Fe/Co-G催化材料进行电化学性能测试,结果表明:B-N-Fe/Co-G在0.1 mol/L的 KOH碱性电解质中有较高的氧还原(ORR)催化活性,起始电位在1.0 V左右,为4电子转移,相比质量分数20%的商用Pt/C催化剂有更好的电化学稳定性。

Preparation of 3D Graphene B-N-Fe/Co-G and Research on Its Catalytic Performance of Oxygen Reduction

The fabrication of three dimensional (3D) graphene doped by Nitrogen,Boron,Ferrum and Cobalt atomics (B-N-Fe/Co-G) was demonstrated by using quick-frozen-drying and pyrolysis methods through the reactions between rGO and low cost industrial raw materials (urea,boric acid,iron nitrate,and cobalt acetate) to study the active substances of the oxygen reduction.The structure and morphology of the B-N-Fe/Co-G were investigated by scanning electron microscopy (SEM),transmission electron microscopy (TEM),X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),and Raman spectroscopy.The results showed the 3D porous graphene structure of B-N-Fe/Co-G with fold surface overlapping and these atoms (N、B、Fe and Co) were equably doped in graphene.The electrocatalytic activity of the hybrid material for oxygen reduction was demonstrated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV).The electrochemical measurements indicated that the B-N-Fe/Co-G showed an initial potential around 1.0 V with four-electron reductions way and superior stability compared with 20% of the commercial Pt/C catalyst in acidic solutions.