中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 19 No. 3 June 2009 |
γ-Mo2N for supercapacitors
(1. School of Chemical Engineering, Hefei University of Technology, Hefei 230009, China;
2. Anhui Key Laboratory of Controllable Chemical Reaction and Material Chemical Engineering,
Hefei University of Technology, Hefei 230009, China)
Abstract:Uniform nanoparticles of molybdenum nitride were synthesized by temperature-programmed reaction(TPR) using MoO3 and ammonia as reactants. This material was characterized by X-ray diffractometry(XRD), transmission electron microscopy(TEM), scanning electron microcopy(SEM) and cyclic voltammetry(CV). Results show that the material consists of a pure phase of γ-Mo2N nanoparticles with average diameter of about 16 nm. The material presents a specific capacitance of 172 F/g in 1 mol/L H2SO4 electrolyte at a scan rate of 1 mV/s and the potential window is broadened to 1.1 V (−0.6 to 0.5 V). At the 6 000th cycle, the material remains 94.9% and 94.7% of the initial capacitance in 1 mol/L H2SO4 and KCl solution, respectively. A possible mechanism comprising surface control and diffusion control is proposed to explain the effect of scan rates on specific capacitance.
Key words: molybdenum nitride; cyclic voltammetry; specific capacitance; scan rate