Fabrication of efficient Au@TiO2/rGO heterojunction nanocomposite: Boosted photocatalytic activity under ultraviolet and visible light irradiation

Abstract

In the present study, we have performed a modified solvothermal process to prepare gold-titania (Au@TiO2) binary nanocomposite anchored into reduced graphene oxide (rGO). The experimental protocol was conducted through one-pot step using only metals precursors and fresh rGO aqueous solution without recourse to added surfactants or capping agents. The DMSO was used as solvent in this solvothermal protocol. Deep techniques including X-ray diffraction powder (XRD), Raman spectroscopy and high-resolution transmission electron microscopy (HRTEM) confirm the successful formation of this heterojunction. The ternary Au@TiO2/rGO exhibited interesting absorption of light in both UV and visible regions. Compared to pristine TiO2 and binary Au@TiO2, the ternary nanocomposite revealed high efficiency in photocatalytic decomposition of organic pollutants molecules and dyes. The increase of photocatalytic performance can be associated to the broad absorption spectrum of the ternary nanocomposite which can enhance the photogenerated electrons–holes pairs and therefore increase the photochemistry reaction at the photocatalyst surface. Moreover, the rGO layers act as outstanding electron transporter which facilitating effective separation of electron–hole pairs. The present work provides an insight into preparing of ternary nanostructures based rGO materials for photoactive UV–visible light photocatalyst.

Keywords

• Solvothermal
• Titanium dioxide
• Gold nanoparticles
• rGO
• Heterojunction
• Photocatalyst