Inorganic–organic hybrid porous materials based on graphite oxide sheets

Graphite oxide hybrid porous materials were constructed by the cross-linking of graphite oxide sheets using the reaction of organic diisocyanates with the carboxyl and hydroxyl groups on both sides of the sheets. In the inorganic–organic hybrid materials, graphite oxide sheets are building blocks and the diisocyanates are covalent cross-linkers acting as spacers between the sheets. Infrared spectroscopy verified the chemical functionalization of the carboxyl and hydroxyl groups. Raman spectroscopy demonstrated that the skeleton structure of graphite oxide remains after diisocyanate treatment. Nitrogen sorption analysis revealed a much larger surface area of the obtained porous materials compared with that of the powdery graphite oxide, indicating that diisocyanate molecules act as covalently linked nanoscale spacers between the sheets and effectively limit their face-to-face stacking.