Enhanced photocatalytic activity of graphene oxide/titania nanosheets composites for methylene blue degradation

Document Type

Article

Publication Date

1-1-2015

Abstract

In the present work, we report enhanced photocatalytic degradation of methylene blue dye in aqueous solution by using ultra-thin anatase TiO2 nanosheets (NSs) combined with graphene oxide (GO) as a photocatalyst. The two-dimensional ultra-thin anatase TiO2 NSs are fabricated via chemical exfoliation. By completely delaminating a lepidocrocite-type layered protonic titanate HxTi2-x/4□x/4O4·H2O (x=0.7, □: vacancy) into individual layers through ion exchange with tetrabutylammonium (TBA+) cations, well-dispersed ultra-thin colloidal Ti0.91O2 NSs with a lateral size up to a few micrometers are obtained. Subsequent acid treatment induces colloidal Ti0.91O2 to reassemble and precipitate into a gelation form, followed by thermal annealing to convert the Ti0.91O2 gelation into anatase TiO2 nanosheets as photocatalyst for methylene blue degradation. TiO2 NSs show a high photocatalytic degradation efficiency of 53.2% due to the ultra-thin thickness for facile electron transfering and large surface area for methylene blue absorption. Moreover, photocatalytic effect can be further improved by simply adding GO suspension to achieve colloidal self-assembly of GO and TiO2 NSs. An optimal GO content of 3 wt% further increases the photocatalytic degradation efficiency to 91.2% due to faster electron-hole seperation and improved surface area provided by GO. This work provides a simple but effective approach by combing graphene oxide with TiO2 nanosheets synthesized via the exfoliation method for methylene blue degradation.

Publication Source (Journal or Book title)

Materials Science in Semiconductor Processing

First Page

592

Last Page

598

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