Fullerene nanorods supported cobalt nickel sulfide composite as efficient electrocatalyst for oxygen evolution

Abstract

New types of clean and renewable energy conversion and storage technologies such as water electrolysis, fuel cells and metal-air batteries have brought new hopes for solving the world's increasingly serious energy shortage and pollution problems. These electrochemical technologies include important electrode reactions, such as hydrogen evolution reaction (HER), and oxygen evolution reaction (OER). However, the slow kinetics of OER has become a bottleneck restricting the overall efficiency of water splitting. The state-of-the-art OER catalysts are mainly based on Pt, Ir, and Ru in commercial applications today, which are expensive and lack of reserves. Therefore, researchers are working hard to develop highly active and stable non-noble metal compounds as alternatives. In this work, we constructed a novel hybrid nanostructure with ultra-small cobalt nickel sulfide nanoparticles decorated on PVP-modified solvent-free fullerene nanorod (sf-FNR-PVP/CoNi2S4). Benefiting from the efficient charge transfer from CoNi2S4 to FNR matrix, the hybrid material exhibited enhanced OER activity during the electrocatalytic reaction. Impressively, the Tafel slope of sf-FNR-PVP/CoNi2S4 was 82 mV dec−1, and the charge transfer resistance is 74.2 Ω, much better than that of CoNi2S4. Besides, the sf-FNR-PVP/CoNi2S4 exhibited robust electrocatalytic durability. This work provides new opportunity for fullerenes in the field of energy conversion and storage.