Development of SiO2/rGO from Rice Husk for Photocatalysis, Antioxidant, Electrochemical and Green Sensor Detection Studies

Abstract

This study reports the extraction, characterization and development of reduced graphene oxide (rGO) doped silicon dioxide (SiO2) nanocomposite by simple reflux method. The nanocomposite was confirmed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV-Visible spectroscopy techniques. The photocatalysis of malachite green (MG) was carried out for rGO, SiO2 and SiO2/rGO nanocomposite shows higher MG degradation about 97% compared to rGO, SiO2 and follows 1 st order kinetics. The antioxidant action of SiO2/rGO nanocomposite was assessed using DPPH shows a more antioxidant activity (98 %) and lower IC50 about 488.35 mg/mL. From electrochemical, the specific capacitance (Csp) value of SiO2/rGO (114 F/g) was exhibits higher compared to rGO (75 F/g) and SiO2 (96 F/g) respectively. The CV and sensor detection of bee pollen and cow urine samples were performed using nickel mesh electrode in 1M KCl in the potential range -1 to 1 V. The SiO2/rGO was employed to analyze bee pollen and cow urine concentrations and the detection limits were found to be 0.260 mM and 0.413 mM respectively. The prepared electrode plays an important role for improving sensor detection of bee pollen and cow urine samples.