Effect of nanosized particles of α-Ni(OH)2 in enhancing the electrochemical capacitance as against the microsized particles of the same hydroxide is examined. Nanomaterial was synthesized by hydrothermal method while the micromaterial was prepared by the conventional co-precipitation method. Material characterization was done by XRD, TEM and BET surface area. Electrochemical characterization was carried out by cyclic voltammetry in alkali solutions. The BET surface areas of of nano- and micro-sized α-Ni(OH)2 were shown to be directly proportional to their specific electrochemical capacitance (both faradic and non-faradic) as evident from the values of 20.9 m2g-1, 289.8 Fg-1 and 9.2 m2g-1, 133.6 Fg-1 respectively. Apart from inter-grain conduction, smaller particles increase the shift of conduction and valence band leading to a greater charge separation. An attempt to understand the particle size effect on the enhancement of electrochemical capacitance based on the volume and surface recombination of oppositely charged particles was made.
|Number of pages||10|
|Journal||International Journal of Electrochemical Science|
|Publication status||Published - 2006|
Bibliographical noteFunding Information:
This work was financially supported by the Ministry of Education and Human Resources Development (MOE), the Ministry of Commerce, Industry and Energy (MOCIE) and the Ministry of Labor (MOLAB) through the fostering project of the Lab of Excellency and by the ERC program of MOST/KOSEF (Grant No. R11-2002-102-00000-0). M. M. Rao thanks KOFST, Republic of KOREA for Brain Pool Fellowship.
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