The hierarchical TiO2 hollow microspheres with exposed high-energy {001} crystal facets composite reduced graphene oxide and its photocatalytic activity

Abstract

A two-step hydrothermal method was used to prepare a hierarchical TiO2 hollow microspheres with exposed high-energy {001} crystal facets composite reduced graphene oxide nanocomposite with a hydrothermal temperature of 180 °C for 10 h. {001} crystal facets and hierarchical TiO2 hollow microspheres were controlled by F ions and Ostwald Ripening, and the reduced graphite oxide (rGO) is composited on the surface of the TiO2 hollow microspheres by high temperature and high pressure in a closed vessel. The hierarchical hollow microsphere structure can not only enhance the light absorbing ability by light scattering, but also reduce the charge transmission distance and thereby suppress the recombination of photogenerated electron–hole pairs. When rGO is composite, the specific surface area of the composite is increased, thereby providing lots of reactive sites and accelerating the surface reaction. Rhodamine B (RhB) was used as a simulated pollutant to detect the photocatalytic activity of the prepared sample. When the {001} crystal facets-exposed hierarchical TiO2 hollow microspheres composite rGO, it exhibited excellent photocatalytic activity, and 15 mg L−1 of RhB can be degraded by 90.08% in 90 min.