Cobalt-based CoSe/CoO heterostructure: A catalyst for efficient oxygen evolution reaction

Hydrogen is known as the fuel for 21st century, the best and clean method to produce hydrogen is electrolysis of water. The oxygen evolution reaction (OER) is of vital position in water splitting, enabling the production of clean hydrogen fuel and contributing to renewable energy solutions. However, the inherently sluggish nature of the OER presents a major challenge for practical water electrolysis but at the same time electrocatalysts play a pivotal role by overcoming this challenge through accelerating the reaction kinetics and reducing the energy requirements. In the realm of electrocatalysts for OER, cobalt-based materials have gained significant attention due to their low overpotential and cost-effectiveness. Among prepared catalysts, the CoSe/CoO heterostructure has emerged as a standout performer, offering an optimal balance of efficiency and minimal overpotential. This electrocatalyst exhibits exceptional electrochemical performance, featuring a low 1.31 V onset potential (vs. RHE) and a mere 170 mV overpotential at a current density of 40 mA/cm2 for OER, setting a new standard for Co-based catalysts. Moreover, the CoSe/CoO heterostructure surpasses Co based bench mark electrocatalysts by displaying the lowest overpotential. Moreover, when subjected to controlled potential electrolysis at 1.65 V (vs. RHE) with a stable current density of 60 mA/cm2, it showcases remarkable electrochemical stability, affirming its practicality for real-world applications. The hydrothermal synthesis of CoSe, CoO, and their heterostructure (CoSe/CoO) represents a straightforward and accessible approach, rendering them as promising candidates for water splitting, specifically in the context of oxygen evolution. These outstanding results achieved with non-precious metal electrocatalysts open new avenues for practical OER applications, providing a platform for the scientific community to advance the development of effective electrocatalysts using non-noble metals in the field of electrochemical water splitting.