Effect of the carbon loading on the structural and photocatalytic properties of reduced graphene oxide-TiO2 nanocomposites prepared by hydrothermal synthesis
This work deals with the preparation of reduced graphene oxide (RGO)-TiO2 composites by a one-step hydrothermal treatment. The effect of the RGO loading on both the structural properties and photocatalytic behavior of RGO-TiO2 is deeply addressed herein. The hydrothermal treatment promoted the reduc...
| Autores: | , , , , , , , , , , |
|---|---|
| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2019 |
| País: | Brasil |
| Recursos: | Universidade Federal de Minas Gerais (UFMG) |
| Repositório: | Repositório Institucional da UFMG |
| Idioma: | inglês |
| OAI Identifier: | oai:repositorio.ufmg.br:1843/46908 |
| Acesso em linha: | https://doi.org/10.1016/j.jmrt.2019.10.020 http://hdl.handle.net/1843/46908 https://orcid.org/0000-0002-1543-5416 https://orcid.org/0000-0001-6813-2999 https://orcid.org/0000-0001-6437-0009 https://orcid.org/0000-0002-0308-0179 https://orcid.org/0000-0002-0873-1671 https://orcid.org/0000-0002-7562-0285 https://orcid.org/0000-0002-6357-9553 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Reduced graphene oxide Tin dioxide Titania Sol-gel process Photocatalytic evaluation Grafeno Óxido de grafeno Dióxido de titânio |
| Resumo: | This work deals with the preparation of reduced graphene oxide (RGO)-TiO2 composites by a one-step hydrothermal treatment. The effect of the RGO loading on both the structural properties and photocatalytic behavior of RGO-TiO2 is deeply addressed herein. The hydrothermal treatment promoted the reduction of graphene oxide, crystallization of TiO2 into anatase, and anchoring of TiO2 nanoparticles on RGO sheets. It was observed that the prepared anatase particles showed sizes below 10 nm, whereas the RGO sheets displayed thicknesses smaller than 1 nm. The use of RGO at concentrations up to 15 wt% greatly increased the specific surface area of RGO-TiO2. It was demonstrated that the combination of RGO and TiO2 gives rise to materials with improved photocatalytic properties and tailored structural properties. The composite with the highest photoactivity was the one containing an RGO loading of 1 wt%; this composite displayed a photocatalytic rate constant about 9.5 times higher than that evaluated for pure TiO2. This behavior may be related to the stacking of RGO nanosheets when its concentration is above 1 wt%. Moreover, the addition of RGO in excess may prevent the activation of the TiO2 surface by UV light and also decrease the lifetime of the photogenerated electron-hole pairs. Therefore, it appears that 1 wt% is the optimal loading of RGO to obtain a close interfacial contact between RGO and TiO2, leading to both an effective activation of TiO2 by UV radiation and an enhanced charge transfer between RGO and TiO2. |
|---|