Methods of making a carbon nanotube material and uses thereof are described. The methods can include obtaining a carbon-containing polymeric matrix shell having a single discrete void space defined by the carbon-containing polymeric matrix shell or having an encapsulated core and subjecting the carbon-containing polymeric matrix shell to a graphitization process to form a shell having a carbon nanotube network from the matrix. The resulting carbon nanotube material includes a shell having a network of carbon nanotubes and either (i) a single discrete void space defined by the network of carbon nanotubes or (ii) the encapsulated core surrounded by the network of carbon nanotubes.