Abstract
Present investigation reports the biomimetic synthesis of mixed metallic oxides nanoparticles (NPs) comprising of zirconia, zinc oxide and palladium oxide ([ZrO2/ZnO/PdO]-NPs) functionalized via nature's bio-factories for the first time. [ZrO2/ZnO/PdO]-NPs express reduction revealed via Fourier transform infra-red spectroscopy and gas chromatography and mass spectrometry. X-ray diffraction express poly-crystallinity. The fabrication of green NPs is confirmed via energy-dispersive X-ray spectroscopy with irregular morphologies visible by scanning electron micrographs. A direct bandgap of 2.11 eV is obtained for [ZrO2/ZnO/PdO]-NPs. Promising surficial features are disclosed via X-ray photoelectron spectroscopy. The electro-catalytic potential is studied using linear sweep voltammetry and electrochemical impedance spectroscopy for investigation of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities with low over-potential of 0.37 V and Tafel slope of 74 mV/dec, indicating the suitability for OER. [ZrO2/ZnO/PdO]-NP electro-catalyst is also tested for HER, demonstrating remarkable results with the overpotential and Tafel slope value of 157 mV and 151 mV/dec.
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•Green NPs as green energy candidates are substitute for fossil fuels.•Biomimetic [ZrO2/ZnO/PdO]-NPs fabricated via green solvo-thermal route.•Remarkable features revealed via FT-IR, GC-MS, XRD, EDX, FE-SEM, UV–Vis and XPS.•Polycrystalline lattice system of [ZrO2/ZnO/PdO]-NPs.•Efficient electro-catalyst for OER expressed by LSV and CV.