Nanoscale cobalt-oxide electrocatalyst for efficient oxygen evolution reactions in alkaline electrolyte

Abstract

Advancement of the effective, stable, earth-rich, low-cost, and highly efficient electro-catalysts commonly demanded large-scale commercial applications toward the low-carbon economy. Here our group demonstrated the synthesis, characterization and electrochemical performance of highly effective and versatile cobalt oxide nanoparticles (Co3O4 NP’s) layered on fluorinated tin oxide (FTO) for efficient water splitting strategy. The synthesized Co3O4 NP’s were analyzed by Scanning Electron Microscopy, Particle Size Analyzer, Zeta Potential, X-ray Diffraction, Ultraviolet–Visible Absorption Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy. The Co3O4 NP’s were deposited on FTO using inexpensive as well as leading electro-deposition method and by simple spray method. Hence, prepared Co3O4 electrocatalysts is found to be highly efficient for water oxidation without any pre-conditioning. This Co3O4 electrocatalyst, layered at FTO through electro-deposition method, is first used in Oxygen evolution reactions (OER). Electrochemically deposited Co3O4 NP’s at FTO proved itself a better electrode than simple spray-coated Co3O4 NP’s at FTO electrode and initiated the oxygen onset potential around 1.49 V versus reversible hydrogen electrode (RHE) (ŋ = 260 mV). The observed Tafel slope was 53 mV dec−1 during the oxygen evolution reaction and the peak of the current density J/ 68 mA cm−2 was observed at 1.78 V versus RHE, which is novel for cobalt-based electrocatalyst system. The conclusions drawn were comparable with both the pricey state of the art IrO2 and RuO2 electrocatalyst systems. In the long term water electrolysis experiment, the electrocatalyst also offered durability and enduring stability. This innovative approach offers a simplest technique to prepare cost-effective and super effectual nanoscale electrocatalyst for water electrolysis.