Spray pyrolysis of graphene oxide based composite for optical and wettability applications

Abstract

In this study, silica-graphene oxide nano-composites were prepared by sol-gel technique and deposited by spray pyrolysis method on glass substrate. The effect of changing the graphene/silica ratio on the optical properties and wetting of these nano-structures has been investigated. The structural and morphological properties of the thin films have been studied by x-ray diffraction spectroscopy (XRD), field emission scanning electron microscope (FESEM), energy dispersive x-ray spectroscopy (EDS) and atomic force microscope (AFM). XRD results show that silica structures present in the synthesized films exhibit amorphous character and there is a poor arrangement in graphene plates along their accumulation directions. The relationship between the contact angle of the water drop and the surface of thin films was analyzed by surface roughness. The results show that the contact angle is also decreased by decreasing the surface roughness. Absorption and transmittance spectra obtained from (UV-vis) of the studied films were used to compute and determine some optical parameters such as absorption coefficient, transmittance rate, optical gap, refractive index and extinction coefficient of the films. The calculated optical band gaps of films decrease by increase the silica contents in these structures.

Synthesis, characterization, photoluminescence, and antibacterial activities of silica-graphene oxide composites

“…GO structure has been reported to have a broad diffraction peak of about 11 ° with a base space of 0.86 nm [33]. Following the ultrasonication of the GO colloidal with TEOS and their mixing, GO diffraction peak is sharply reduced and almost disappears, indicating the large distance of GO layers due to amorphous SiO 2 bonding [32,34]. In the thin film as well as nano-powders of Si-GO10 and Si-GO30, a relatively strong peak is observed at an angle of 25° with an interlayer distance of 3.35Å [35].…”

“…The existence of this peak is ascribed to loading silica to the material. However, the peak disappeared when the ratio of graphene increases due to reducing oxygen contents of graphene oxide as a consequence of graphitization phenomenon [32].…”

“…In this view, Bakhsheshi-Rad et al [31] reported that nano-SiO 2 /GO coating exhibits an effective antibacterial activity and high corrosion resistance of the Mg alloy. Very recently, our group [32] has successfully synthesized silica-graphene oxide nano-composites via sol-gel method and deposited on glass substrate by spray pyrolysis for both optical and wetting purposes.…”