Electrostatic self-assembly of TiO2 nanoparticles onto carbon spheres with enhanced adsorption capability for Cr(VI)

A rapid electrostatic assembly method has been developed for deposition of highly dispersed TiO2 nanoparticles on the surface of carbon spheres. Surface charges on carbon spheres are found to facilitate the spontaneous deposition of the TiO2 nanoparticles, in which no additional chemicals are required in this assembling process. In the formed C/TiO2 hybrid structure, carbon microspheres not only reduce the agglomeration of TiO2 nanoparticles, but also allow easy separation from the reaction medium for reuse. Remarkably, the as-prepared C/TiO2 hybrid microspheres exhibit a superior adsorption capacity for Cr(VI), which is 3.6 times greater than that of commercial Degussa P25 TiO2 nanoparticles. The effect of pH value in solution on the adsorption capacity of the products has also been systematically investigated. (c) 2011 Elsevier B.V. All rights reserved.