Highly Efficient and Stable Mn-Co1.29Ni1.71O4 Electrocatalysts for Alkaline Water Electrolysis: Atomic Doping Strategy for Enhanced OER and HER Performance.

Water electrolysis for hydrogen production has garnered significant attention due to its advantages of high efficiency, environmental friendliness, and abundant resources. Developing cost-effective, efficient, and stable materials for water electrolysis is therefore crucial. In this work, we synthesized a series of highly efficient multifunctional Mn-Co1.29Ni1.71O4 electrocatalysts through an atomic doping strategy for alkaline electrocatalysts. The unique structure features and large specific surface area of these catalysts provide abundant active sites. The Mn-Co1.29Ni1.71O4 catalysts exhibit an excellent oxygen evolution reaction (OER) performance in 1.0 M KOH electrolyte, with an overpotential of 334.3 mV at a current density of 10 mA cm-2 and 373.3 mV at 30 mA cm-2. Additionally, the catalysts also demonstrate a Tafel slope of 76.7 mV dec-1 and outstanding durability. As hydrogen evolution reaction (HER) electrocatalysts, it shows an overpotential of 203.5 mV at -10 mA cm-2 and a Tafel slope of 113.6 mV dec-1. When the catalysts can be utilized for the overall water splitting, the catalyst requires a decomposition voltage of 1.96 V at 50 mA cm-2. These results indicate that the high catalytic activity and stability of Mn-Co1.29Ni1.71O4 samples make it a highly promising candidate for industrial-scale applications.