Three-Dimensional Network of Highly Uniform Cobalt Oxide Microspheres/MXene Composite as a High-Performance Electrocatalyst in Hydrogen Evolution Reaction

Abstract

Due to its affordable cost, excellent redox capability, and relatively effective resistance to corrosion in alkaline environments, spinel Co 3 O 4 demonstrates potential as a viable alternative to noble-metal-based electrocatalysts. Nevertheless, these materials continue to exhibit drawbacks, such as limited active surface area and inadequate intrinsic conductivity. Researchers have been trying to increase the electrical conductivity of Co 3 O 4 nanostructures by integrating them with various conductive substrates due to the low conductivity of pristine Co 3 O 4 . In this study, uniform cobalt glycerate solid spheres are first synthesized as the precursor and subsequently transformed into cobalt oxide microspheres by a simple annealing procedure. Co 3 O 4 grown on the surface of Ti 3 C 2 T x -MXene nanosheets (Co 3 O 4 /MXene) was successfully synthesized through electrostatic attraction. In order to create a positively charged surface, the Co 3 O 4 microspheres were treated with aminopropyltriethoxysilane. The Co 3 O 4 /MXene exhibited a low overpotential of 118 mV at 10 mA cm −2 and a Tafel slope of 113 mV dec −1 for the hydrogen evolution reaction, which is much lower than the pristine Co 3 O 4 at 232 and 195.3 mV dec −1 .

Architectural Decoration of Bioleached NiFeP Surfaces by Co3O4 Flowers for Efficient Electrocatalytic Hydrogen Generation

“…The deconvoluted Co 2p spectra shown in Figure B2 are observed to exhibit characteristic peaks corresponding to Co 3+ and Co 2+ representing Co 2p 3/2 and Co 2p 1/2 at ∼780, ∼782, ∼786, and ∼796 eV, respectively. These reported values are in accordance with the binding energies of Co 3 O 4 reported elsewhere. , Further, both the Ni 2p (Figure B3) and Fe 2p (Figure B4) spectra of the Co 3 O 4 @NiFeP-5 coatings when compared to those of the bioleached systems are observed to exhibit a slight shift in binding energy values, attributed to the effectual electronic interaction between Co, Ni, and Fe . Furthermore, the unique assembling of Co 3 O 4 on the bioleached NiFeP-5 coatings facilitated close and robust interaction among the as-obtained nanostructures.…”