A vertical chemical vapor deposition (CVD) reactor and a method for synthesizing metal oxide impregnated carbon nanotubes. The CVD reactor includes a preheating zone portion and a reaction zone portion, and preferably an additional cooling zone portion and a product collector. The method includes (a) subjecting a liquid reactant solution comprising an organic solvent, a metallocene, and a metal alkoxide to atomization in the presence of a gas flow comprising a carrier gas and a support gas to form an atomized mixture, and (b) heating the atomized mixture to a temperature of 200° C.-1400° C., wherein the heating forms a metal oxide and at least one carbon source compound, wherein the metallocene catalyzes the formation of carbon nanotubes from the at least one carbon source compound and the metal oxide is incorporated into or on a surface of the carbon nanotubes to form the metal oxide impregnated carbon nanotubes.