MOF–graphite oxide nanocomposites: surface characterization and evaluation as adsorbents of ammonia

Metal-organic framework (MOF-5)–graphite oxide (GO) composite was synthesized using a solvothermal synthesis route. The parent materials (MOF-5 and GO) and the nanocomposite were characterized using X-ray diffraction, SEM, TEM, FTIR and adsorption of nitrogen. They were also tested as adsorbents of ammonia in dynamic conditions. The composite material obtained had a unique layered texture with a preserved structure of MOF-5 and GO. When tested as ammonia adsorbent, the composite showed some synergy enhancing the adsorption capacity in comparison with the hypothetical physical mixture of the components. Although the removal capacity was high in the presence of moisture, water had a detrimental effect on the chemistry of materials and destroyed their porous framework. This caused ammonia retained on the surface to be progressively desorbed from the materials when the samples were purged with air.