Biomass-Derived Green Synthesis of ZnO/NiO Nanocomposite from Salsola baryosma Extract for Electrocatalytic Formaldehyde Oxidation
摘要
This work introduces green methodology to prepare ZnO/NiO nanocomposite electrode using Salsola baryosma plant extract. The prepared ZnO/NiO nanocomposite is characterized through physicochemical techniques to study its crystallinity, morphology, and chemistry. The surface morphology is studied through electron microscopes, as well as studying chemical contents at the surface of ZnO/NiO nanocomposite via X-ray photoelectron microscopy. Additionally, FT-IR indicates the dominant peaks for Zn–O and Ni–O stretching vibration modes primarily, which were found at 435–645 cm− 1. The prepared ZnO/NiO NPs have an average crystal size of 19.32 nm according to XRD analysis. Surface texture analysis showed a BET specific surface area around 6.5 m2/g and pore volume of 0.119 cm3/g. Then, the electrocatalytic performance is studied for formaldehyde electrooxidation in alkaline media. Electrochemical techniques were investigated using ZnO/NiO nanocomposite as a working electrode at a glassy-carbon electrode. This nanocomposite electrode exhibits redox behavior and an enhanced electrocatalytic response toward formaldehyde electrooxidation. The found anodic peak current increased up to 14.641 mA/cm2, which can affirm the successful formaldehyde electrooxidation. Additionally, enhanced charge transfer and stability were found which is confirmed by reduced charge transfer resistance and chronoamperometry (CA) data. The current density values were stable at 9.2085 mA/cm2 from CA analysis. Impedance analysis indicates distinct phase angle shifts and Nyquist behavior in the presence of formaldehyde, which can affirm the new charge transfer process with formaldehyde due to its electrooxidation. This study introduces the role of Salsola baryosma as a sustainable source for green nanomaterials in advanced electrochemical applications.