A General Strategy for the Preparation of Hollow Carbon Nanocages by NH₄Cl‐Assisted Low‐Temperature Heat Treatment

Empty cages: Iron/graphite core–shell nanoparticles are produced by pyrolysis of a mixture of acetylene and iron carbonyl. Then, the core–shell nanoparticles are heat treated in the range of 300–500 °C in the presence of NH4Cl. After filtration in water, the trapped iron particles are completely removed and hollow carbon nanocages with a good graphitic structure are obtained (see graphic).