Toward Advanced Water-Splitting Electrocatalysts via Molecular Engineering of Metal–Organic Frameworks

The efficiency of electrochemical water splitting is predominantly governed by two central processes: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). While noble metal catalysts like Pt/C show exceptional HER performance, their high-cost limits widespread use. The exceptionally high surface areas and tunable porosity of metal–organic frameworks (MOFs) render them highly promising for electrocatalytic applications. However, challenges in scalable synthesis and stability remain between research and industrial application. Designing efficient non-noble metal-based alternatives is crucial. Herein, we design a molecularly engineered 2D MOF system constructed from hierarchical copper–organic coordination networks. The CuBTC framework was employed as a bifunctional electrode for overall water splitting. At a current density of 10 mA cm–2, the cell voltage required was 1.75 V, demonstrating promising electrocatalytic performance and stability. The overpotentials for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) were measured as 268 and 165 mV, respectively. This work offers an innovative strategy for designing MOF-based electrocatalysts to advance water electrolysis efficiency.