Graphdiyne-Supported NiCo2 S4 Nanowires: A Highly Active and Stable 3D Bifunctional Electrode Material.

The oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting are major energy and chemical conversion efforts. Progress in electrocatalytic reactions have shown that the future is limitless in many fields. However, it is urgent to develop efficient electrocatalysts. Here, the first graphdiyne-supported efficient and bifunctional electrocatalyst is reported using 3D graphdiyne foam as scaffolds, and NiCo2 S4 nanowires as building blocks (NiCo2 S4 NW/GDF). NiCo2 S4 NW/GDF exhibits outstanding catalytic activity and stability toward both OER and HER, as well as overall water splitting in alkaline media. Remarkably, it enables a high-performance alkaline water electrolyzer with 10 and 20 mA cm-2 at very low cell voltages of 1.53 and 1.56 V, respectively, and remarkable stability over 140 h of continuous electrolysis operation at 20 mA cm-2 . The results indicate that this catalyst has a bifunction that overcomes all reported bifunctional, nonprecious-metal-based ones.