Testing of NiO–Al2O3–CoO–MnO2 composite catalysts for indoor water splitting through electrocatalysis

Abstract

Generating hydrogen through electrolysis in water offers a sustainable and environmentally friendly energy alternative. It is desperately needed to develop efficient metal oxide-based composite electrode materials for efficient water splitting, high electrode stability, and improved hydrogen evolution activity. In this work, we produced NiO/CoO/Al₂O₃/MnO₂ composite electrode material through a multicomponent hydrothermal synthesis. Different compositions of the electrode material, namely, Electrode 1, Electrode 2, and Electrode 3, were used in electrocatalysis for hydrogen evolution reaction (HER). It was revealed that only 0.21 V potential is required to achieve a current density of 10 mAcm⁻² with the tested Electrode 1 material. Relatively lower Tafel slope values of 53 mV dec⁻¹, 163 mV dec⁻¹, and 175 mV dec⁻¹ were calculated for Electrode 1, Electrode 2, and Electrode 3, respectively, indicating fast HER. The larger surface area, smaller particle size, high electrochemical stability, and robust metallic bonding facilitated the electrode–electrolyte interaction and, consequently, the HER. Electrode 1 driven reaction produced 603 ml, Electrode 2 produced 282 ml, and Electrode 3 produced 259 ml of hydrogen. This research approach presents a practical and cost-effective solution for hydrogen production at a larger scale.