Reactive adsorption of hydrogen sulfide on graphite oxide/Zr(OH)4 composites

Zirconium hydroxide/graphite oxide composites with the content of graphite oxide component between 5% and 50% were used as adsorbents of hydrogen sulfide from humid air at room temperature. The initial and exhausted materials were characterized using adsorption of nitrogen, infrared spectroscopy, potentiometric titration, X-ray fluorescence, X-ray diffraction, and thermal analysis. The results indicated enhanced adsorption of H2S on the composites (an increase of about 20% compared to zirconium hydroxide) owing to their increased basicity and formation of specific adsorption centers on the interface between GO and hydrous zirconia. Moreover, taking into account the acidity of zirconium hydroxide surface, there is an indication that hydrogen sulfide reacts with epoxy and carboxylic groups of GO layers forming their thio-derivatives. During the process SO2 was released, which is linked to the oxidation of hydrogen sulfide ions by oxygen from the atmosphere.