THREE-DIMENSIONAL YARN BALL-LIKE NICKEL COBALT OXIDE AS AN ELECTROCATALYST MATERIAL FOR FUEL CELL APPLICATION

Nor Fatina Raduwan; Norazuwana   Shaari

Nor Fatina Raduwan FUEL CELL INSTITUTE, UKM
Norazuwana Shaari FUEL CELL INSTITUTE, UKM

Keywords: Nickel cobalt oxide, binary transition metal oxide, specific surface area, 3D nanostructures, fuel cell

Abstract

The shape, size and specific surface area play a major contribution in determining the catalytic activity of an electrocatalyst. In order to control them, hydrothermal reaction time is one of important parameter tailoring the desired morphological and structures. Through this facile method, nickel cobalt oxide (NiCo2O4) has been successfully synthesized with various reaction time (6, 12, 18, 24h). The cubic spinel crystal of all the synthesized NiCo2O4 is obtained according to the standard pattern. The smallest crystallites size of 19.12 nm is obtained by powder synthesized for 18 hours based on the Scherrer formula calculation from X-ray diffraction (XRD) analysis. The field emission scanning electron microscopy (FESEM) micrograph demonstrates all the synthesized NiCo2O4 consists of three-dimensional (3D) nanoflakes that interconnected to each other and resemble a yarn ball with deteriorated structures when the reaction time is increasing. From Brunauer–Emmett–Teller (BET) analysis, the 3D yarn ball-like structures synthesized for 6 hours yield a very high specific surface area. The ultrathin nanoflakes provide a large surface area to accelerate the electrochemical reaction of the catalyst thus increase the performance of a fuel cell system. Hence, this 3D yarn ball-like NiCo2O4 synthesized by hydrothermal can be a promising electrocatalyst material for fuel cell application.