Three-Dimensional Network of Highly Uniform Cobalt Oxide Microspheres/MXene Composite as a High-Performance...

Due to its affordable cost, excellent redox capability, and relatively effective resistance to corrosion in alkaline environments, spinel Co₃O₄ 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 Co₃O₄ nanostructures by integrating them with various conductive substrates due to the low conductivity of pristine Co₃O₄. 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. Co₃O₄ grown on the surface of Ti₃C₂T-MXene nanosheets (Co₃O₄/MXene) was successfully synthesized through electrostatic attraction. In order to create a positively charged surface, the Co₃O₄ microspheres were treated with aminopropyltriethoxysilane. The Co₃O₄/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 Co₃O₄ at 232 and 195.3 mV dec^-1.