Nickle-ion-substituted ceria nanoparticles-based electrochemical sensor for sensitive detection of thiourea

Nickel-substituted ceria nanoparticles (CeO2:Ni NPs) were prepared by the co-precipitation process under environmental conditions. X-ray diffraction (XRD), field emission-transmission electron microscopy, UV/visible, X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy techniques were successfully used to investigate the crystallographic structure, phase purity, morphology, optical properties, chemical composition, and electrocatalytic properties of the as-prepared ceria NPs. XRD pattern shows the formation of single-phase, highly crystalline, and cubic phase nanostructure with an average of 10 nm crystalline size. As observed from TEM micrographs, particles were highly aggregated may be due to the synthesis in aqueous media. The electrochemical properties and sensing performance of the CeO2:Ni NPs pasted on glassy carbon electrode were measured against different thiourea concentrations. The fabricated electrode revealed excellent electrocatalytic activity against thiourea concentrations as well as characterization in comparison to the bare electrode. The electrode exhibited a linear detection range between 3.56 and 1000 mu M, detection limit 3.56 mu M, and sensitivity 2.52 mu A mL mu M-1 cm(-2) with regression coefficient 0.995. The electrochemical stability, chemical kinetic, and reproducibility were also examined in the presence of thiourea in phosphate buffer solution.