Semi-conducting Ni/Zn nano-hybrids’ driven efficient electro-catalytic performance: fabrication, characterization, and electrochemical features’ elucidation

Abstract

The current work reports the synthesis, analytical evaluation, and electrochemical performance investigation of green bio-factories’ triggered mixed metal oxides’ nano-hybrids comprising of nickel (Ni) and zinc (Zn) for the first time. Modified sol–gel synthetic route used for the synthesis of NiO/ZnO green nano-hybrids ([NiO/ZnO]-GNH) is devoid of utilization of any chemical-reducing agents. Efficient [NiO/ZnO]-GNH electro-catalysts were characterized for various aspects using Fourier transform infra-red spectroscopy (FT-IR), gas chromatography and mass spectrometry (GC-MS), energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron micrographs (FE-SEM), UV-Visible spectrophotometry (UV-Vis), and X-ray photoelectron spectroscopy (XPS). Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) steps of water splitting reactions were evaluated via linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) via fabrication of modified Ni-foam electrode through decoration of [NiO/ZnO]-GNH. The as-synthesized [NiO/ZnO]-GNH promises electro-catalytic performance with a small over-potential of 0.42 V and 264 mV for OER and HER, respectively, for the achievement of a current density of 10 mA/cm2. Results of the current work can be extended to the practical scale adoption of the fabricated electro-catalysts through optimized investigation and economical evaluation for the consolidation of environmental sustainability and green energy production.

Keywords

• green energy
• metal oxides
• nanomaterials
• sustainability
• water splitting