A general protocol to coat titania shell on carbon-based composite cores using carbon as coupling agent

We present herein a general protocol to coat titania shell on carbon-based composite cores via the hydrolysis of titanium tetrabutoxide in a mixed solvent with the catalysis of ammonia. As coupling agent, their carbonaceous component can adsorb counter-charged NH4+, and then the negatively charged ≡TiO− species are adsorbed via electrostatic interaction to form TiO2 shell. Various carbon-based cores with different functional components, such as Ag/C core/shell spheres, Ag/C nanocables, as well as magnetic (C–Fe3O4) hollow spheres can be coated with titania shell to form corresponding core/shell composites. Their optical or magnetic property is also investigated. Finally, anatase-phase titania shell with rough surface can be generated via hydrothermal treatment of aforementioned titania coated composites, which can further introduce the properties of anatase-phase titania to the composites.