Abstract
The article describes the conversion of MOF-199 to Cu-Cu2O-CuO/C 700 (1) and Cu-Cu2O-CuO/C 800 (2) nanostructures by simple pyrolysis at 700 and 800 degrees C under inert atmosphere. The X-ray photoelectron spectroscopy analysis reveals that the nanostructures Cu-Cu2O-CuO/C consist of graphitic carbon functionalized with carboxylic, carbonyl and hydroxyl functional groups with copper/copper oxide particles on surfaces. The electro-chemical properties of 1 and 2 are evaluated as electrode material for supercapacitors using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results for the capacitive performance from cyclic voltammetry and galvanostatic charge/discharge reveal that both the samples have gravimetric capacitance greater than 750 F g(-1) at a scan rate of 2 mV s(-1) and current density of 2 mA cm(-2). The samples retain about 43% of their initial capacitance even at high scan rate of 75 mV The cycling performance of the nanostructures illustrate that there is 5.5% capacitance loss after 3000 cycles. The sample 1 and 2 are washed with 1 mol L-1 HCl solution to obtain copper oxide free materials Cu/C 700 (3) and Cu/C 800 (4). Samples 3 and 4 are tested as electrocatalysts for glucose sensing and the cyclic voltammetry measurement shows enhanced current densities compared to the literature values. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.