부산대학교 도서관

Cubic spinel Co3O4nanoparticles 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 Co3O4particles 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 (O2-→ Co2+,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 Co3O4particles exhibited comparatively better characteristics with high specific capacitance (476 F g–1), energy density 42.3 Wh kg–1and power density 1.56 kW kg–1at current density of 0.5 Ag–1, that suited for potential applications in supercapacitors. The observed better electrochemical properties of the nanoporous Co3O4particles is attributed to the layered platelet structural arrangement of the hexagonal platelet and the presence of exceptionally high numbers of regularly ordered pores.