Structural modification of nano TiO2 using stearic acid for electrochemical detection of Cd ions in aqueous systems

Abstract

This research used tetraethyl ortho titanate as a starting material to synthesize {001}-facet nano TiO₂ using stearic acid as an organic modifier. The synthesized sample was characterized using X-ray diffractometer (XRD), Thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC), X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Fourier transformed infra-red (FTIR) and UV-visible Spectrophotometer. Crystallographic parameters and the facet formation were evaluated using XRD data. The working electrode was fabricated using {001}-facet nano TiO₂ for selective and sensitive detection of heavy metal, Cadmium (Cd), using an electrochemical technique. The sensitivity of the TiO₂-modified glassy carbon electrode was evaluated using the potassium ferrocyanide. Qualitative and quantitative analyses were performed using different electrochemical techniques along with the estimation of the surface area of the working electrode. Different equations such as Randles–Sevcik, and Laviron equations were also utilized to characterize the efficacy of the {001}-facet TiO₂-modified glassy carbon working electrode for the Cd-ions detection. Highly sensitive working electrode exerted very good results where the limit of detection (LOD) was 2.8 × 10⁻⁴ ppb, the limit of quantification (LOQ) was 8.7 × 10⁻⁴ ppb, the sensitivity was 0.1276 µA/ppb, and the linear range was 0.1-100 ppb.