Ag₂Cu₂O₃ Nanorods as Electrocatalysts for Hydrogen Production and Overall Water Splitting

In this research, a series of Ag2Cu2O3 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.