Nanostructures of graphene oxide modified with ZnO: synthesis and photocatalyst evaluation under sunlight

Abstract

Multiple nanostructures of graphene oxide (GO) and Zinc oxide (ZnO) have been prepared via alcoholic reduction of GO, where took place the ZnO incorporation with different weight ratios. The X-ray diffraction patterns shown the ZnO anchored between GO sheets consequently produce a significant displacement of the GO characteristic pattern to lowers angles. In addition, the alcoholic reduction process allows generating another Zinc Nanostructure, the presence of Zinc Peroxide (ZnO₂) is confirmed by two signals at 37.8° and 43.1° in XRD. The metallic semiconductor anchored is evident in Raman Spectra, because a displacement of D and G band. The ZnO characteristics bands appear in the spectra, however, near to 474 cm⁻¹ a small band is shown, this band indicates the presence of ZnO₂, reaffirming the observed in XRD. In thermogravimetric analysis (TGA) the materials (GO, rGO/ZnO) shown similar tendencies, but, in DTG curves is observed different reactions because the species presents in the materials. Bandgap estimation was calculate by Reflectance UV–vis spectroscopy, adjusted by Kubelka-Munk, all rGOZnO material presents visible light activation. By photodegradation of Methylene Blue (MB) under sunlight confirms the Bandgap estimation obtained by Kubelka-Munk. In this work, the alcoholic reduction of GO for metallic semiconductors anchored is a viable method, improving optical and electronic properties of ZnO, allowing these material multiple applications such as optoelectronic, photovoltaic devices and photocatalysis.

Keywords:

• Graphene oxide
• bandgap
• ZnO
• methylene blue

Disclosure statement

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Additional information

Funding

TecNM, CONACYT for Scholarship 2912361.