This study represents a green synthesis method for fabricating an oxygen evolution reaction (OER) electrode by depositing two-dimensional CuFeOx on nickel foam (NF). Two-dimensional CuFeOx was deposited on NF using in situ hydrothermal synthesis in the presence of Aloe vera extract. This phytochemical-assisted synthesis of CuFeOx resulted in a unique nano-rose-like morphology (petal diameter 30-70 nm), which significantly improved the electrochemical surface area of the electrode. The synthesized electrode was analyzed for its OER electrocatalytic activity and it was observed that using 75% Aloe vera extract in the phytochemical-assisted synthesis of CuFeOx resulted in improved OER electrocatalytic performance by attaining an overpotential of 310 mV for 50 mA cm-2 and 410 mV for 100 mA cm-2. The electrode also sustained robust stability throughout the 50 h of chronopotentiometry studies under alkaline electrolyte conditions, demonstrating its potential as an efficient OER electrode material. This study highlights the promising use of Aloe vera extract as a green and cost-effective way to synthesize efficient OER electrode materials.
This study explores a water-splitting activity using a biphasic electrodeposited electrode on nickel foam (NF). The *Ni9S8/Cu7S4/NF electrode with citric acid reduction exhibits superior OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) performance with reduced overpotential and a steeper Tafel slope. The *Ni9S8/Cu7S4/NF electrode displays the ultra-low overpotential value of 212 mV for OER and 109 mV for HER at the current density of 10 mA cm-2. The Tafel slope of 25.4 mV dec-1 for OER and 108 mV dec-1 for HER was found from that electrode. The maximum electrochemical surface area (ECSA), lowest series resistance and lowest charge transfer resistance are found in citric acid reduced electrode, showing increased electrical conductivity and quick charge transfer kinetics. Remarkably, the *Ni9S8/Cu7S4/NF electrode demonstrated excellent stability for 80 hours in pure water splitting and 20 hours in seawater splitting. The synergistic effect of using bimetallic (Cu&Ni) sulfide and enhanced electrical conductivity of the electrode are caused by reduction of metal sulfide into metallic species resulting in improved water splitting performance.