▎ 摘　　要

NOVELTY - A composite comprises porous graphene oxide material and ammonia borane, where porous graphene oxide material has a density of 1-100 mg/cm3. USE - A composite for hydrogen-releasing device and energy-producing device for use in an aircraft (all claimed). ADVANTAGE - In the composite, the release temperature of hydrogen from ammonia borane can be reduced to lower temperatures more suitable for mobile applications. The nanoconfinement of the ammonia borane in the composite lowers the hydrogen release temperature. Furthermore, the nanoconfinement also increases the selectivity of side products. The hydrogen obtained from decomposition of the ammonia borane confined in the composite also has an improved purity. The monolith form or bead form, i.e. not a powder form, makes the composite more robust and easier to handle. The monolith form or bead form also contributes to a lower toxic risk compared to powders in general and in particular to nanopowders because formation of dust which may be inhaled is significantly decreased when handling the monoliths or beads. Additionally, if the composite is used in any hydrogen-releasing device, the risk of elution of the composite from the hydrogen-releasing device with a hydrogen stream is significantly reduced when the composite has a monolith form or bead form. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparation of the composite which involves sonication dispersion of a suspension comprising graphene oxide and ammonia borane, ice-templating of the sonicated suspension comprising graphene oxide and ammonia borane to obtain frozen monoliths or beads of the suspension comprising graphene oxide and ammonia borane, and freeze-drying of the obtained frozen monoliths or beads of the suspension comprising graphene oxide and ammonia borane; and (2) energy-producing device comprising the composite and a fuel cell. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of preparing the composite having laminar porosity.