Studi Komposisi dan Ketebalan Polivinil Alkohol/Grafen Oksida/Kobalt Oksida untuk Elektroda Selektif Ion Fosfat

Abstract

Electrodeposition on cobalt electrodes has been studied in previous experiments, the results show that the electrode response has good linearity and sensitivity to phosphate ions, but cannot be used in the long term. This is due to the weak interaction between cobalt and the electrode body. Based on that research, PVA/GO/CoO composite electrodes were developed in this experiment. This experiment aims to determine the results of FTIR characterization of composite materials and the influence of composite composition and thickness on the linearity and sensitivity of the electrode. Then, the performance of the optimum electrode was studied using the parameters of linearity, sensitivity, reproducibility, and detection limit by potentiometrics. The PVA/GO/CoO composite electrode was prepared by synthesizing GO using the Hummers method, then mixed with other composite constituents and designed into plastic tubes. The composites was characterized by FTIR spectroscopy and tested for the influence of their composition and thickness on the linearity and sensitivity of the electrode. The variation in the composition of GO:CoO in this experiment was 0.3:0.1 grams; 0.25:0.15 grams; 0.2:0.2 grams; 0.15:0.25 grams; and 0.1:0.3 grams. While the thickness variation is 0.3 cm; 0.5 cm; and 0.7 cm. The results of the characterization test by FTIR showed the presence of PVA compounds indicated on 3291 cm-1, GO compounds at 1035 cm-1, and CoO compounds at 667 cm-1. The PVA/GO/CoO electrode with a ratio of 0.2:0.2 grams and a thickness of 0.5 cm indicate the best performing electrodes, were they produced a linearity of 0.9855 and a sensitivity of -14.295 mV/decade. The optimum electrode has also been evaluated and produced a reproducibility of 0.9129% and a limit detection of 2.82 x 10-6 M.