Plasma-modified Ni foam-supported CuCo2S4 nanowires as bifunctional electrocatalysts for high-performance overall water splitting

Abstract

To solve the current energy and environmental dilemma, hydrogen energy is considered to be the best clean energy source to replace traditional fossil fuels. Water electrolysis as the main technology for hydrogen production has been affected by two half-reactions, making it difficult to improve the yield. To solve this problem, the development of inexpensive and efficient bifunctional electrocatalysts is the focus of current research. CuCo2S4/NF(Ni foam) nanowires are synthesized using a mild hydrothermal process and were later placed in a plasma reactor. Application of the voltage triggers a chemical reaction between the microdischarge wires and the sample. This leads to a change in the physical morphology of the catalyst and an improvement in its catalytic performance. The morphological characterization results show that the catalyst modification generates a distinct flower-like nanowire structure, which helps in the solid attachment of the catalyst to the nickel foam surface. The plasma-modified CuCo2S4/Ni foam (PA@CuCo2S4/NF) exhibits low overpotentials of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solutions. Additionally, the Tafel slopes of the HER and OER are 85.9 mVdec−1 and 142.7 mVdec−1, respectively, indicating optimal reaction kinetics. A cell voltage of only 1.55 V is required to provide a 10 mA cm−2 current during water splitting. This study validates the feasibility of using plasma technology to create high-performance electrocatalysts.