Graphene Oxide Incorporated Zinc Oxide Thin Films by Spray Pyrolysis for Efficient Photodegradation of Methylene Blue

Abstract

Photodegradation of methylene blue dye was studied with pure and graphene oxide incorporated zinc oxide thin films as catalysts. Graphene oxide content in the precursor solution was varied from 0.0005 to 0.005 g/L. Thin films were prepared by automated spray pyrolysis technique at a substrate temperature of 425 °C. Structural studies revealed the formation of hexagonal wurtzite structure of zinc oxide. Carbon presence in the films was confirmed with energy‐dispersive spectroscopy. Optical band gap of the samples was determined using Tauc method. Intensity of the near band emission of photoluminescence spectrum was found to decrease upon increasing graphene oxide concentration. Photocatalytic activity of all the films has been studied against methylene blue dye under solar irradiation for 180 minutes and it is found that the highest graphene oxide content attributes to better degradation efficiency of 91.2 %.

Photodegradation of methylene blue dye using graphene oxide incorporated, post-transition metal doped zinc oxide thin films by spray pyrolysis

“…It is evident from the figure 9 that highest degradation efficiency of 94.9% is achieved for the sample ZIG, which is 7.5% more efficient than ZG. In addition, ZIG is 19.4% more efficient than pure ZnO as reported in a previous study with same experimental conditions [19]. The degradation efficiency can be related to the intensity of NBE in PL spectra given in figure 6.…”

“…Graphene oxide powder (> 99% pure, Techinstro) was added to 100 ml of the parent solution and ultrasonically stirred for 15 min to get a uniform dispersion. The amount of GO is fixed to 0.00375 g/l since better degradation efficiency against MB dye was observed in an earlier work [19]. The solution was sprayed for 11 min at a rate of 7 ml min −1 onto a cleaned soda lime glass substrate (76 mm × 26 mm × 1 mm) kept at 425 °C [16].…”