Template-assisted synthesis of hollow TiO2@rGO core-shell structural nanospheres with enhanced photocatalytic activity

Reduced graphene oxide (rGO) wrapped hollow TiO2 nanospheres have been synthesized successfully via a simple two-step method, which involves preparation of SiO2@TiO2@GO core/shell structures without any modified agents and subsequently etching of the SiO2 core materials. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray and detector (EDX), X-ray photoelectron spectroscopy (XPS), respectively. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic decolorization of Rhodamine B (Rh B) both under ultraviolet and visible light irradiation. SEM and TEM images revealed that the diameter of the reduced graphene oxide wrapped hollow TiO2 nanospheres (HRGT NSs) is about 350-400 nm, while the thickness of TiO2 and graphene shell is about 15 nm and 5 nm, respectively. The photocatalytic degradation results indicated that the HRGT NSs showed an enhanced photocatalytic activity than pure hollow TiO2 nanospheres (HT NSs) and P25 both under ultraviolet and visible light irradiation. And the excellent photocatalytic ability of the HRGT NSs could be mainly attributed to its enhanced absorption performance for organic pollutants and separation efficiency for photogenerated electron-hole pairs both under ultraviolet and visible light irradiation condition. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.