Influence of the thermal process of carbon template removal in the mesoporous boron nitride synthesis

Influence of the thermal process involved in the carbon template elimination during the synthesis of mesoporous boron nitride by using nanocasting process of a mesoporous CMK-3 carbon with a borazinic precursor is presented. The borazinic precursor, the tri(methylamino)borazine (MAB), is converted to boron nitride (BN) inside the mesopores of a CMK-3 mesoporous carbon template by ceramization under nitrogen or under ammonia. The carbon template elimination is carried out by thermal treatment under air or under ammonia. The X-ray diffraction, TEM and pore size analysis are used to study the texture of the boron nitride synthesized from the carbon template. A template elimination performed by hydrogenation with an ammonia treatment allows to obtain an organized porous structure, which is not possible by using an oxidation treatment. In order to preserve the mesoporous organization of boron nitride, a two steps procedure (ceramization followed with template elimination by hydrogenation) is more efficient than a one step procedure (ceramization and template hydrogenation simultaneously).