Calcium copper titanate-modified electrode for selective lead detention in water: Linking structure to sensing

This research explores an electrochemical sensing technique utilizing nanostructured calcium copper titanate (CaCu₃Ti₄O₁₂, CCTO)-modified graphite electrode for lead detection in water, establishing a clear structure-sensing link. A precipitation-calcination route was used to synthesize the CCTO. This material was characterized by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and X-ray photoelectron spectroscopy (XPS), confirming its crystallinity, phase purity, thermal stability, and favorable surface chemistry. The XRD examination indicated an average crystallite size of 157 nm with a cubic perovskite structure. TGA/DSC demonstrated remarkable thermal stability over 900 °C. FTIR and XPS analysis revealed strong metal-oxygen interaction and the existence of mixed valence states at the surface, which is required for redox activity. Linear sweep anodic stripping voltammetry (LSASV) was utilized to evaluate the scan rate (30–70 mV/s), deposition voltage (-0.9 V to −1.3 V), deposition time (120 s to 200 s), and concentration variation (0.5–50 ppm), demonstrating excellent sensitivity, linearity, and repeatability for Pb 2 + detection, achieving a lower detection threshold of 0.5 ppm along with offering a robust, low-cost, and scalable method for real-time monitoring of heavy metals in water systems, and possesses further future development for other heavy metal detection by electrochemical sensors.