Electrocatalytic Activity Enhancement of Multifunctional Co₃O₄ Nanorods for Glucose Sensing and Oxygen Evolution Reaction

Abstract

To explore a methodology for tailoring the d-band center of metal oxide catalysts, a distinctive composite is synthesized by incorporating polyaniline (PANI) particles with specific atoms of Co 3 O 4 nanorods. The introduction of the requisite amount of PANI significantly enhances the electrocatalytic activity, yielding an excellent functionality with a minimum detection limit of 0.676 μM and a high sensitivity of 3.024 μA μM −1 cm −2 for glucose. The opening potential for the oxygen evolution reaction registers at 1.41 V, while the overpotential is 290 mV. However, when the PANI layer completely covers the Co 3 O 4 surface, a substantial decline in electrochemical properties is observed, indicating that active atoms on the Co 3 O 4 plane should be preferentially exposed. Additionally, density functional theory calculations reveal that bonding of an appropriate quantity of polyaniline particles can modify bonding states and antibonding states of Co−O within the Co 3 O 4 complex, leading to a shift of the d-band center closer to the Fermi level, thereby enhancing its electrocatalytic activity. These findings underscore the practicality of this manipulation strategy for glucose sensing and oxygen evolution reaction.

Pt Single-Atom Catalyst on Co3O4 for the Electrocatalytic Detection of Glucose

“…To overcome this challenge, the development of nonprecious metal nanomaterials has emerged as a promising approach for glucose detection. Currently, Ni, Co, and Cu have been widely explored in electrochemical nonenzyme glucose sensing applications. , In particular, Co-based catalysts offer several advantages, including cost-effectiveness, high conductivity, nontoxicity, and remarkable electrocatalytic performance toward glucose. − Various Co-based nanostructures, such as nanoparticles, nanorods, and flower-like structures, have demonstrated immense potential in electrochemical glucose sensing due to their high aspect ratio and large surface area . These features facilitate enhanced glucose detection sensitivity.…”