Abstract:
The electrocatalytic reduction of greenhouse CO2 gas into value-added fuels or chemical feed stocks is a set of technologies that can provide energy in a sustainable way and reduce the concentration of anthropological CO2 gas in our environment. This strategy is considerably effective or attractive for resolving the two essential problems environmental and energy crises. However, CO2 reduction is categorically helpful when using the electro-catalyst as it has shown a specific form of function at electrode surfaces. In this work, we demonstrated the catalytic behavior of flower like cobalt oxide (Co3O4) for the electrocatalytic reduction of CO2 gas. Flower like cobalt oxide (Co3O4) is incorporated into P doped rGO supporting materials to make the reduction more effective by making a hybrid electro-catalyst. The chemical, morphological and structural characterization of the synthesized catalyst was carried out using Scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The electrocatalytic reduction of CO2 is performed in 0.5M NaHCO3 aqueous solution at the pH of 7.5 (CO2 condition) in three electrode system and applying potential vs Ag/AgCl (3M KCl sat.) as reference electrode, platinum wire as counter electrode and prepared catalyst as modified working electrode. The chronoamperometry approach shows the conversion stability of CO2 under applying the constant voltage -0.62 V (vs Ag/AgCl) for 2.5 hours. The catalysts are capable of reducing CO2 yielding ethanoic acid and propionaldehyde. Ethanoic acid is the major product in Flower like cobalt oxide (Co3O4) catalyst which has a 69 % faradaic efficiency for a constant geometric current density remains -0.5 mA/cm 2. Also, ethanoic acid and propanal is found for the hybrid flower like cobalt oxide (Co3O4)/P-rGO catalyst with 58% and 9% faradaic efficiency with a constant current density of -0.8 mA/cm2. The results show that the performance towards the electrocatalytic reduction of CO2 can be improved by incorporating the flower like cobalt oxide (Co3O4) into the P-rGO supporting material. This can provide a unique platform to synthesis and fabricate a shape-based materials flower Like Co3O4 and hybrid flower Like Co3O4/P-rGO as an electro-catalyst paving the way for a future powered by renewable boundless energy and wealth from greenhouse CO2 gas and other pollutants.
Keywords: Electrochemical reduction of CO2, Flower Like Cobalt oxide (Co3O4), Flower Like Co3O4/P-rGO, Electrocatalysis, GC-MS