Fabrication of rGO/α-Fe2O3 electrodes: characterization and use in photoelectrocatalysis

• Autor(a) principal: Leão-Neto, Vanildo Souza
• Data de Publicação: 2020
• Outros Autores: da Silva, Aruã Clayton, Camargo, Luan Pereira, Da Silva Pelissari, Marcelo Rodrigues [UNESP], da Silva, Paulo Rogério Catarini, Parreira, Paulo Sergio, Segatelli, Mariana Gava, Dall′Antonia, Luiz Henrique
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1007/s10854-020-04244-3; http://hdl.handle.net/11449/199311

In the current study, the synthesis of hematite (α-Fe2O3) at different temperatures (750 and 900 °C), and reduced graphene oxide (rGO), obtained from an adaptation to the Hummers’s method, was evaluated. These materials were characterized by X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, among others. The deposition of samples on the conductive surface of tin-doped indium oxide coated glass substrate, was performed by the Layer-by-Layer technique. The films were prepared with 1- and 4-bilayers α-Fe2O3, using a cationic polyelectrolyte diallyldimethylammonium chloride (PDDA) or rGO. It was observed that the rGO/α-Fe2O3 films presented higher photocurrent and less resistivity when compared to the PDDA/α-Fe2O3 films. The largest photocurrent was obtained with the 4-bilayers rGO/α-Fe2O3 at 900 °C film, with 2.15 µA cm−2. In addition, a kinetic study for photoelectrocatalytic decolorization of the methylene blue dye under visible light was performed. The electrode that showed the greatest photoelectroactivity was the 4-bilayers rGO/α-Fe2O3 at 900 °C film, resulting in kobs = 11.90 × 10−3 min−1 and about 78% decolorization after 120 min.