Preparation and characterization of ZnO hollow spheres and ZnO-Carbon composite materials using colloidal carbon spheres as templates

In this paper, a general strategy for synthesis of carbon-based core/ZnO-shell-type composite and hollow materials is reported. These materials include colloidal carbon spheres@ZnO nanospheres, ZnO-carbon composite "dandelions", ZnO-carbon branched "dandelions", Au-ZnO-carbon composite "dandelions", and size-tunable hollow ZnO spheres. As-synthesized composite "dandelions" exhibited a color change, which originated from the surface plasmon resonance of gold nanoparticles, showing their optical application. All products obtained show well photocatalytic activities and ZnO-carbon composite "dandelions" have the highest photocatalytic efficiency in all products.