Semiconducting cobalt oxide nanocatalyst obtained through an eco-friendly thermal decomposition

Abstract

The combination of an intense absorption of visible light and p-type semiconducting nature makes spinel cobalt oxide (Co3O4) a very attractive material for various optoelectronic applications. However, the traditional methods for its synthesis have been either time- and energy-consuming or relying on toxic chemicals. To solve this issue, a simple, facile, and eco-friendly method of synthesis was successfully developed to obtain spinel Co3O4 nanoparticles. The novel method for obtaining pure and monophasic Co3O4 reported here is based on the thermal decomposition of hexaaquacobalt(II) D-camphor10-sulfonate at 900 °C. This fast solid-state synthesis route overcomes the disadvantages of many combustion methods, most critically by avoiding the use of toxic organic solvents. The synthesized material was subjected to a detailed characterization to assess its potential for use as a nanocatalyst. The band gap measurements indicated the presence of two band gaps, one at 2.10 eV and another at 1.22 eV, confirming the purity and semiconducting properties of the sample. The electrochemical studies demonstrated a significant enhancement in the electron transfer kinetics with the addition of the synthesized Co3O4 to the carbon-paste electrode, leading to an enhanced electrocatalytic performance. These prominent functional properties, suitable for a wide range of technological applications, pave way for the implementation of the reported method for the synthesis of Co3O4 on a larger industrial scale.