Ammonia Borane Nanospheres for Hydrogen Storage

Nanosizing ammonia borane NH3BH3 (AB) is an attractive approach to make it suitable for chemical hydrogen storage. Herein is reported the successful direct preparation of ammonia borane nanospheres. No scaffold is used. The preparation is performed via a simple process using alkaline water H2O as main solvent, a common and thermally stable surfactant like cetyltrimethylammonium bromide (CTAB), and dodecane C12H26 as counter-solvent. Interestingly the protic solvent H2O, when kept at pH > 7, has no hydrolytic effect on ammonia borane, allowing nanosizing with the safest solvent. Ammonia borane nanospheres with an average diameter of 110 nm can then be obtained via a protocol where the molar ratio AB/CTAB is 5060/1 and the volume ratio H2O/C12H26 is 1. Such an achievement should open new prospects for ammonia borane in the field of hydrogen storage but also as precursor of nanostructured B,N-based materials for energy and environmental applications.