Abstract
The electrocatalytic reduction of greenhouse CO(2) gas into value-added fuels or chemical feedstocks sustainably addresses energy and environmental crises. However, CO(2) reduction is particularly effective with electrocatalysts, which exhibit distinct functionality at electrode surfaces. In this work, we demonstrate the electrocatalytic reduction of CO(2) using flower-like cobalt oxide (Co(3)O(4)) synthesized via a hydrothermal method. Co(3)O(4) is incorporated into P-doped rGO via ultrasonication to form a hybrid electrocatalyst, thereby enhancing CO(2) reduction efficiency by improving electrode surface functionality. Chemical, morphological, and structural characterization of the synthesized catalyst was carried out using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analysis. The electrocatalytic reduction of CO(2) was performed in 0.5 M NaHCO(3) aqueous solution at a pH of 7.5 (CO(2) conditions) in a three-electrode system and applying potential vs. Ag/AgCl (3 M KCl sat.) as the reference electrode, platinum wire as the counter electrode, and the prepared catalyst as a modified graphite working electrode. Chronoamperometry shows CO(2) conversion stability under a constant voltage of -0.62 V (vs. Ag/AgCl) for 2.5 hours. The Co(3)O(4) catalyst primarily yields ethanoic acid with 69% faradaic efficiency at a current density of -0.5 mA cm(-2). Additionally, ethanoic acid and propanal are detected for the hybrid flower-like Co(3)O(4)/P-rGO catalyst, with 58% and 9% faradaic efficiencies at a constant current density of -0.8 mA cm(-2). These results highlight that incorporating Co(3)O(4) into the P-rGO improves reduction performance. This can provide a promising platform for synthesizing and fabricating shape-based materials as an electrocatalyst, paving the way for a future powered by renewable, boundless energy and wealth from greenhouse CO(2) gas and other pollutants.