Ruthenium-modified porous NiCo2O4 nanosheets boost overall water splitting in alkaline solution

Abstract

Exploring efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalysts is crucial for developing water splitting devices. The composition and structure of catalysts are of great importance for catalytic performance. In this work, a heterogeneous Ru modified strategy is engineered to improve the catalytic performance of porous NiCo2O4 nanosheets (NSs). Profiting from favorable elements composition and optimized structure property of decreased charge transfer barrier, more accessible active sites and increased oxygen vacancy concentration, the Ru-NiCo2O4 NSs exhibits excellent OER activity with a low overpotential of 230 mV to reach the current density of 10 mA/cm2 and decent durability. Furthermore, Ru-NiCo2O4 NSs show superior HER activity than the pristine NiCo2O4 NSs, as well. When assembling Ru-NiCo2O4 NSs couple as an alkaline water electrolyzer, a cell voltage of 1.60 V can deliver the current density of 10 mA/cm2. This work provides feasible guidance for improving the catalytic performance of spinel-based oxides.