Ag2Cu2O3 Nanorods as Electrocatalysts for Hydrogen Production and Overall Water Splitting

Abstract

In this research, a series of Ag<inf>2</inf>Cu<inf>2</inf>O<inf>3</inf> nanorods as electrocatalysts were prepared with three different drying temperatures (namely, W - 50, W - 80, and W - 120), utilizing a regular coprecipitation approach. These nanorods’ surface morphology and structural attributes were thoroughly characterized using Field Emission Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy, while X-ray diffraction provided insight into their crystal structures. The compositional analysis was accomplished via X-ray photoelectron spectroscopy and Raman spectroscopy. The W - 50 catalyst exhibited the most promising electrochemical response among the synthesized samples. In the solution of 1 M KOH, at a current density of 10 mA cm-2, it demonstrated modest overpotential values and Tafel slopes of 81 and 97 mV dec-1 for the hydrogen evolution reaction (HER), whereas 409 and 140 mV dec-1 for the oxygen evolution reaction (OER). When tested with a two-electrode electrolyzer, W - 50 serving as together the anode and cathode, a trivial cell voltage of 1.9842 V was required to accomplish a current density of 100 mA cm-2, with surprising stability over 50 h of continuous operation at 200 mA cm-2 for overall water splitting. Additionally, W - 50 displayed excellent performance for HER; it necessitated an overpotential of 337 mV to accomplish an extreme current density of 800 mA cm-2. This inquiry provides precious perceptions into the importance of confined spaces within transition metal oxide-based catalysts, advancing their application in electrocatalysis. © 2025 American Chemical Society.