SYNTHESIS AND CHARACTERIZATION OF CdS/Ag2CO3 and UiO66/CdS/Ag2CO3 NANOCOMPOSITE ELECTROCHEMICAL SENSOR FOR THE DETERMINATIONS OF TRACE METAL IONS

Abstract

Zirconium based Metal organic framework (UiO-66), Cadmium sulfide (CdS), silver carbonate (Ag2CO3), binary system CdS/UiO-66, UiO-66/Ag2CO3, CdS/Ag2CO3 and the ternary CdS UiO-66/Ag2CO3 by sol-gel and co-precipitation method to employ GCE modified by these materials as electrochemical toxic metals sensors. The crystanility, structure and composition of the as prepared nanocomposites were characterized using X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscope (SEM). The electrochemical properties of different GC modified electrodes on the other hand were investigated by employing cyclic voltammetry (CV). The XRD result reveals ternary system has lowest particle size than others Due to the Ternarey Nano have ahighest Band gap energy from others. The FTIR confirms the formation the expected nanomaterials. The modified GCE by UiO66, CdS/UiO-66, UiO-66/Ag2CO3,CdS/Ag2CO3and CdS/UiO-66/Ag2CO3 were characterized using CV. The result demonstrates that binary system nanocomposite gave a high peak current response with respect to others. This is most probably due to the catalytic properties of CdS and high surface area of the binary system. The redox potential of potassium ferrocynide was near to that of its ideal value indicating the reversibility of the process. The proposed sensor was optimized to identify appropriate experimental condition for cadmium ion detection. The optimum condition was found to be pH 4.6 and scan rate 100 mV/s. Under this condition the sensor was tested for the detection of cadmium in standard solution and exhibits good linearity 2.0 - 8.0 x10- 4mol L−1, sensitivity of 0.00143A mM-1 cm-2 and detection limits 47.1molL-1 (3σ/N). The result shows that CdS/Ag2CO3 can be a potential candidate for routine analysis of toxic heavy metals.