基于双金属MOFs衍生的NiCo/NC多孔碳催化材料的电化学性能研究

Electrochemical Activity of NiCo/NC Porous Carbon Catalytic Materials Derived from Bimetallic MOFs

通过普通溶液法制备了双金属NiCo-ZIF-67纳米晶体,并将其作为前驱体,通过采用不同温度的高温热解得到氮掺杂双金属基碳材料。利用X射线衍射仪(XRD)、场发射扫描电镜(FESEM)、透射电镜(TEM)、X射线光电子能谱仪(XPS)对材料的表面形貌、物相、化学元素分布以及表面化学键价态等进行表征分析;采用线性扫描伏安法(LSV)等电化学测试方法对材料的ORR/OER电催化性能和稳定性进行了研究。结果表明,相比于其他热解温度,在800℃下热解产物NiCo/NC-800的极限电流密度为4.26 mA·cm^(-2),具有接近商用Pt/C的ORR性能;在10 mA·cm^(-2)时NiCo/NC-800的过电势为469.6 mV,且相对应的塔菲尔斜率为98.68 mV·dec^(-1),具有优于商用RuO_(2)的OER性能,且具有良好的稳定性。

Bimetallic NiCo-ZIF-67 nanocrystals were prepared by using an ordinary solution method, as precursor to obtain NiCo/NC-X. X-ray diffraction(XRD), tungsten filament scanning electron microscopy(SEM), field emission scanning electron microscopy(FESEM), transmission scanning electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)were used to characterize surface morphology, phase, chemical element distribution and surface chemical bond valence states of the samples. ORR/OER electrocatalytic properties and stability of the materials were studied by using linear sweep voltammetry(LSV)and other electrochemical testing methods. It is observed that the limiting current density of NiCo/NC-800 at 800 ℃ is 4.26 mA·cm^(-2), which is close to the ORR performance of commercial Pt/C. The overpotential of NiCo/NC-800 is 469.6 mV at 10 mA·cm^(-2)and the corresponding Tafel slope is 98.68 mV·dec^(-1), which has higher OER performance than commercial RuO_(2) and sufficiently high stability.