Atomically precise copper nanoclusters as a potential catalyst for the electrochemical oxygen evolution reaction

Abstract

Metal nanoclusters (MNCs) are gaining interest as electrocatalysts for various electrochemical reactions. Herein, we report a simple method for synthesizing copper nanoclusters (CuNCs@4MP) capped with 4-mercaptopyridine (4-MP), showcasing their potential as electrocatalysts for the oxygen evolution reaction (OER). These nanoclusters, measuring less than 2 nm, exhibit vibrant yellow fluorescence in both solid and solution states, owing to their precise atomic structure. Utilizing their distinct electronic energy levels and active copper centers, CuNCs@4MP show considerable potential in driving the OER in acidic, neutral, and alkaline electrolyte environments. As evidenced by density functional theory-based analyses, it exhibited exceptional OER performance in alkaline conditions with an overpotential of 280 mV at 10 mA cm⁻² and a Tafel slope of 97 mV dec⁻¹. This study paves the way for the development of scalable and cost-effective single metal-based nanoclusters as electrocatalysts for OER, presenting a viable alternative to traditional mixed transition metal oxides.