Economic and binder-free synthesis of NiCo2O4 nanosheets on a Flexible stainless steel mesh as a bifunctional electrode for water splitting

Abstract

Water as a green source of hydrogen has attracted the attention of researchers considering its potential applications in the energy sector. Thus, developing efficient bifunctional electrocatalysts for water splitting is a potential challenge perceived by researchers exploring the development of sustainable energy technologies. With this motive, the present study focuses on the preparation of the highly active, economic, binder-free, and bifunctional NiCo2O4 nanosheets@ Flexible Stainless Steel Mesh substrate (NCO@FSSM) electrocatalyst via reflux condensation method for the bulk O2 and H2 production. The influence of reflux condensation temperatures (100, 120, 140 °C) on the morphology and electrocatalytic activity is investigated. Electrocatalytic properties for NCO@FSSM synthesized at 120 °C were noted exhibiting smaller overpotentials for oxygen evolution reaction (OER, 310 mV) and hydrogen evolution reaction (HER, 79 mV) at 10 mA cm−2, which were lowest among the previously reported Ni, and Co-based electrodes. Additionally, the scale-up experiments with NCO-120@FSSM film (8 cm X 8 cm) as an anode and FSSM as a cathode and vice-versa, in a specially designed scale-up electrochemical cell revealed steady electrocatalytic performance. The real-time water splitting was studied for 25 h and was noted to produce 7.4 L of (O2) and 11.5 L of hydrogen (H2).