Wei Xuedong, Liu Nan, Chen Weifeng, Qiao Shuangyan, Chen Yuanzhen
Key Laboratory of Magnetic Molecules and Magnetic Information Materials Ministry of Education, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and Technology, School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, People's Republic of China.
State Key Laboratory for Mechanical Behavior of Materials, School of Material Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
Nanotechnology. 2021 Apr 23;32(17):175701. doi: 10.1088/1361-6528/abdb60.
Composite electrocatalysts of carbon and metals or metal compounds with homogeneous active sites can be obtained through the carbonization of metal organic framework (MOF) materials under inert atmosphere. In this work, a three-phase composite electrocatalysts NiFeO/Ni@C were prepared via pyrolysis from self-assembled MOF nanosheets aggregates. The excellent electrocatalytic activity of the obtained electrocatalysts with various Ni:Fe ratios is demonstrated. Especially, the NiFeO/Ni@C sample with the mole ratio of Ni:Fe = 1:1 can use the overpotential (η) of 330 and 423 mV to drive 10 and 50 mA cm respectively. After 80 000 s/22 h, the current density could retained 90% of the initial current density. The excellent activity and stability of the electrocatalysts are attributed to nickel and iron ions with uniform dispersion at atomic level in the NiFeO phase and the synergistic effect of nickel and NiFeO nanoparticles with amorphous carbon atoms or nanoparticles around.
碳与金属或金属化合物构成的具有均匀活性位点的复合电催化剂可通过金属有机框架（MOF）材料在惰性气氛下碳化获得。在本工作中，通过自组装的MOF纳米片聚集体热解制备了三相复合电催化剂NiFeO/Ni@C。结果表明，所制备的具有不同Ni:Fe比例的电催化剂具有优异的电催化活性。特别是，Ni:Fe摩尔比为1:1的NiFeO/Ni@C样品分别使用330和423 mV的过电位（η）驱动10和50 mA cm²的电流。在80000秒/22小时后，电流密度可保留初始电流密度的90%。电催化剂优异的活性和稳定性归因于在NiFeO相中原子水平均匀分散的镍和铁离子以及镍和NiFeO纳米颗粒与周围无定形碳原子或纳米颗粒的协同效应。
