From design to efficiency: cobalt-based MOFs for efficient and stable electrocatalysis in hydrogen and oxygen evolution reactions†

The pursuit of clean and renewable energy sources demands efficient technologies for hydrogen production, with water splitting emerging as a promising route. This study explores the use of Cobalt-based Metal–Organic Frameworks (Co-MOFs) as electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Two distinct Co-MOFs, synthesized with the organic linkers 5-nitroisophthalic acid (X1) and pyridine-2,6-dicarboxylic acid (X2), were designed and evaluated for their electrocatalytic performance. X1 exhibited suboptimal morphology and a low specific surface area, resulting in lower catalytical activity and restricting its suitability for long-term applications. In contrast, X2 exhibited exceptional catalytic efficiency with remarkably low overpotentials for both HER (151.7 mV) and OER (180 mV), alongside superior long-term stability. The enhanced electrocatalytic performance of X2 is attributed to its optimized morphology, superior metal-active site distribution, and robust structural integrity, making it an ideal candidate for large-scale water splitting. This work paves the way for the development of high-performance MOF-based electrocatalysts, offering insights for advancing hydrogen generation technologies.