Graphene-based nanocomposite to adsorb water pollutants

(Nanowerk News) Researchers succeeded in the production of particles with smaller size but higher surface area, and consequently more number of active sites, to adsorb pollutants by synthesizing cerium oxide–titanium dioxide nanoparticles and obtaining cerium oxide–titanium dioxide nanocomposite (see paper in Journal of Hazardous Materials: “Assembly of CeO2–TiO2 nanoparticles prepared in room temperature ionic liquid on graphene nanosheets for photocatalytic degradation of pollutants”).
Among semi-conductive photocatalysts, titanium dioxide (TiO2) is an important candidate to be used in many industries due to its high optical stability and non-toxicity. However, it is impossible to use this component in visible light because its energy gap is placed in the range of ultraviolet.
In this research, researchers from Sharif University of Technology in association with researchers from University of Mohaghegh Ardebili and Nanoscience and Nanotechnology Research Center tried to move the energy gap of TiO2 towards longer wavelengths through the synthesis of carbon-based TiO2 / CeO2 nanocomposite. They also aimed to increase the photocatalytic activity of TiO2.
Results of the research showed that the synthesis of TiO2 in an ionic solution and the addition of cerium oxide to the structure of TiO2 decreased the particle size, increased the surface area, and slowed down the phase exchange from anatase to rutile at higher temperatures. As a result, it caused the creation of nanoparticles with higher thermal stability. High activity of the nanocomposite in the degradation of pollutants is explained by the unique structure of graphene, which increases adsorption on the catalyst surface and decreases the re-composition of ion carriers.