Department of Chemistry, University of Delhi, North Campus , Delhi 110007, India.
ACS Appl Mater Interfaces. 2013 Nov 13;5(21):10665-72. doi: 10.1021/am4027482. Epub 2013 Oct 24.
Cubic spinel Co3O4 nanoparticles with spherical (0D) and hexagonal platelet (2D) morphologies were synthesized using a simple solvothermal method by tuning the reaction time. XRD and HRTEM analyses revealed pure phase with growth of Co3O4 particles along [111] and [110] directions. UV-vis studies showed two clear optical absorption peaks corresponding to two optical band gaps in the range of 400-500 nm and 700-800 nm, respectively, related to the ligand to metal charge transfer events (O(2-) → Co(2+,3+)). Under the electrochemical study in two electrode assembly system (Co3O4/KOH/Co3O4) without adding any large area support or a conductive filler, the hexagonal platelet Co3O4 particles exhibited comparatively better characteristics with high specific capacitance (476 F g(-1)), energy density 42.3 Wh kg(-1) and power density 1.56 kW kg(-1) at current density of 0.5 Ag(-1), that suited for potential applications in supercapacitors. The observed better electrochemical properties of the nanoporous Co3O4 particles is attributed to the layered platelet structural arrangement of the hexagonal platelet and the presence of exceptionally high numbers of regularly ordered pores.
采用简单的溶剂热法，通过调节反应时间，合成了具有球形（0D）和六方片状（2D）形态的立方尖晶石 Co3O4 纳米粒子。XRD 和 HRTEM 分析表明，具有沿[111]和[110]方向生长的 Co3O4 颗粒的纯相。UV-vis 研究表明，两个清晰的光吸收峰分别对应于 400-500nm 和 700-800nm 范围内的两个光学带隙，分别与配体到金属电荷转移事件（O(2-) → Co(2+,3+)）有关。在没有添加任何大面积支撑或导电填料的两电极组件系统（Co3O4/KOH/Co3O4）中的电化学研究中，六方片状 Co3O4 颗粒表现出比较好的特性，具有高比电容（476 F g(-1)）、能量密度 42.3 Wh kg(-1)和功率密度 1.56 kW kg(-1)，在电流密度为 0.5 Ag(-1)时，适合用于超级电容器。观察到的纳米多孔 Co3O4 颗粒的更好的电化学性能归因于六方片状的层状片状结构排列和异常高数量的规则有序孔的存在。
