Effects of Surface Features on Adsorption of SO2 on Graphite Oxide/Zr(OH)4 Composites

Zirconium hydroxide/graphene composites were synthesized from zirconium chloride and graphite oxide with the content of the graphene component between 5 and 50%. They were used as adsorbents of sulfur dioxide at ambient conditions. The initial and exhausted materials were characterized using adsorption of nitrogen, infrared spectroscopy, potentiometric titration, scanning electron microscopy and thermal analysis. The results indicated enhanced adsorption of SO2 on the composites, which is linked to the formation of new basic sites and porosity as a result of interactions between zirconium hydroxide units and the oxygen groups attached to the graphene layers. Both physical adsorption and reactive adsorption of SO2 via formation of sulfites play a role in the retention process. The graphene component catalyzes oxidation of SO2 and leads to the formation of sulfates.