Pseudocapacitance of α-CoMoO4 nanoflakes in non-aqueous electrolyte and its bi-functional electro catalytic activity for methanol oxidation

Abstract

Nanocrystalline cobalt molybdate (CoMoO4) nanoflakes were grown directly on carbon fibre cloth (CFC) via a simple hydrothermal method without any template or surfactant. A symmetric supercapacitor was fabricated using CoMoO4 nanoflakes/CFC as both negative and positive electrodes. The device has delivered the maximum specific capacitance of 8.3 F g−1 at a constant current density of 1 A g−1 in organic electrolyte. It offers the reasonable energy (2.6 Wh kg−1) and power density (748.8 W kg−1) as comparable to the carbon based symmetric supercapacitors. As a catalyst for methanol oxidation, the CoMoO4 nanoflakes showed high current density (25 mA cm−2) and low onset potential (0.38 V). The impressive bi-functional electrochemical activity of CoMoO4 on CFC is mainly attributed to its porous microstructure, where reasonable electrical conductivity resulted from binder-free and intimate metal oxide/substrate integration.