Synthesis, Characterization, and Application of Exfoliated Graphite/Zirconium Nanocomposite Electrode for the Photoelectrochemical Degradation of Organic Dye in Water

Abstract

We report the synthesis and application of a novel exfoliated graphite–zirconium oxide nanocomposite photoanode for the photoelectrochemical degradation of eosin yellowish dye in water. Zirconium oxide nanoparticle was synthesized by sol–gel, method and EG–ZrO2 nanocomposite was synthesized by wet solution method. The materials were characterized by scanning electron microscopy, thermogravimetry and differential thermal analysis (TGA-DTA), Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray diffraction (XRD). Applicability of the EG–ZrO2 as photoanode material was investigated by the photoelectrochemical degradation of eosin yellow as a model for organic pollutants in 0.1 M Na2SO4 (pH 7) solution at a current density of 5 mA cm−2 after optimizing the EG–ZrO2 loading. The FTIR, XRD, and Raman data showed the formation of the nanocomposite. The XRD patterns show that the ZrO2 nanoparticle contains mainly the monoclinic phase as complemented by Raman spectroscopy. Photoelectrochemical studies with the EG–ZrO2 nanocomposite showed a significant decrease in the initial dye concentration (20 ppm) compared with the bare exfoliated graphite (EG) and zirconium oxide (ZrO2) only. The results indicate that the ZrO2 nanoparticle in the EG–ZrO2 composite enhanced the degradation efficiency of the EG substrate. Thus, EG–ZrO2 composite can be used for the photoelectrochemical oxidation of organic pollutants, especially organic dyes.