Electrocatalytic water splitting studies on zirconium oxide nanoparticles synthesized by biomimetic synthesis route

Efficient, low cost, robust electrode material for energy related applications is highly needed for the future renewable energy generation. In this research, we explained a novel and environmentally friendly way for synthesizing ZrO2 particles using Olea ferruginea Royle leaves extract. Unlike previous approaches, this method does not require the use of chemical reducing or stabilizing agents. The synthesized particles were thoroughly characterized using various techniques including ultraviolet-visible (UV-Vis) spectroscopy, phase and particle size determination via X-ray diffraction (XRD) spectroscopy, Fourier transmission infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The characterization by FTIR and gas chromatography mass spectroscopy (GCMS), exhibited the existence of a variety of biomolecules in the leaf extract, which demonstrated a vital part in the reduction and stabilization of the ZrO2 particles. The XRD characterization analysis confirmed the formation of phase pure t-ZrO2 particles having a size of 27 nm in average. To identify electrochemical properties of the bio-inspired ZrO2 particles, it was decorated onto a Ni-foam substrate. The resulting composite was then subjected to linear sweep voltammetry (LSV) and chronoamperometry (CA) tests in a 1M KOH electrolyte, with a focus on their potential for water oxidation. The electrode showed a lower over-potential of 0.4 V for OER and excellent HER overpotential of only 42 mV. CA analysis exhibit the long-term durability and stability of bio templated ZrO2 over the time of 6 h. In the light of above results, we believe that phyto-stabilized ZrO2 particles could be the potential catalyst for water oxidation in replacement with the precious noble metals.