基于双金属有机配位聚合物的氮掺杂多孔炭的制备及电化学性能研究

Preparation and performance of N-doped porous carbons derived from bimetallic organic coordination polymer

通过对苯二胺(PPD)与2种金属离子Zn^(2+)、Co^(2+)发生配位络合反应生成双金属有机配位聚合物([Co(PPD)_4Zn]_n)复合物前驱体,再经一步炭化过程形成氮掺杂多孔炭。利用高含氮量的对苯二胺作为有机配体,同时能够作为氮源和碳源。通过SEM、XRD、Raman和XPS对所制备样品PCCo-Zn的微结构、石墨化程度和元素含量进行了表征分析。同时讨论了不同的2种金属离子组合的选择(Zn^(2+)和Co^(2+)、Zn^(2+)和Ni^(2+)和Ni^(2+)和Co^(2+))以及只有单种金属的有机配位聚合物作为前驱体对材料电化学性能的影响,当双金属离子为Zn^(2+)和Co^(2+),焙烧温度为650℃时,获得的氮掺杂多孔炭(PCCo-Zn)具有最佳的电化学性能。在电流密度为0.5 A/g时,比电容为422.6 F/g;电流密度为20 A/g时,比电容仍有192.6 F/g,显示了良好的倍率性能。同时,在电流密度为20A/g时的3 000次恒电流充放电循环,比电容保持率为104.3%,显示出优异的循环稳定性能。优异的综合性能表明所制备的材料作为超级电容器电极材料有着十分广阔的应用前景。

P-phenylenediamine(PPD) and two types of metal ions(Zn2+and Co2+) were performed a coordination reaction, and the obtained bimetallic organic coordination polymer([Co(PPD)4Zn]n) was used as precursor to prepare nitrogen doped porous carbon by one step carbonization. The high nitrogen content PPD was used as both organic ligand and nitrogen source and carbon source. The microstructure, graphitization degree and element content of the prepared samples PCCo-Znwere characterized by SEM, XRD, Raman and XPS, respectively. At the same time, the effects of different two metal ion combinations and the organic coordination polymers of single metal on the electrochemical properties of the materials were also discussed. When the bimetallic ions are Zn2+and Co2+and the carbonization temperature is 650 ℃, the obtained nitrogen doped porous carbon has the optimal electrochemical properties. When the current density is 0.5 A/g, the specific capacitance is 422.6 F/g, and when the current density is 20 A/g, the specific capacitance still has 192.6 F/g, showing a good rate performance(45.6%). Furthermore, after 3 000 cycle at high current density of 20 A/g, the gravimetric specific capacitance still can maintain initial value of 104.3%, showing excellent cycling stability. It shows that the prepared materials have excellent electrochemical properties and have a very broad application prospect as the electrode material of supercapacitors.