Reactive adsorption of hydrogen sulfide on visible light photoactive zinc (hydr)oxide/graphite oxide and zinc (hydr)oxychloride/graphite oxide composites

Authors:  Oluwaniyi Mabayoje, Mykola Seredych, Teresa J. Bandosz

Abstract:
Composites of zinc (hydr)oxide and graphite oxide (GO) with 2, 5, and 20 wt.% of the GO component were obtained by precipitating zinc hydroxide fromzinc chloride with dispersed GO presentin the solution. The materials were evaluated as adsorbents of hydrogen sulfide at ambient conditions. The surface properties of the initial and exhausted samples were studied by FTIR, XRD, SEM/EDX, TEM, nitrogen adsorption, potentiometric titration, microcalorimetry, and thermal analysis. The adsorption capacity increases with an increase in the content of GO in the composites studied. The lower adsorption capacities measured for the samples with 2 and 5 wt.% of graphite oxide are linked to the zinc (hydr)oxychlorides phase presentin these composites. The heats of H2S adsorption on the zinc (hydr)oxide and its composites were measured in nitrogen and in air flow. The results indicate that highly energetic adsorption centers are formed on the composite surfaces. Exposure to visible lightdecreases the H₂S adsorptioncapacity. This behavior is linked to photoactivity that leads to the reduction of the composite and formation of sulfur and sulfites/sulfates. These processes involve active centers, OH groups, which react with hydrogen sulfide. 

Keywords:
Visible light activity
Graphite oxide
Zinc (hydr)oxide
Zinc (hydr)oxychlorides
Composites
H₂S adsorption
Surface reactivity

Published in: Applied Catalysis B: Environmental (Volumes 132–133, Pages 1-552, 27 March 2013)

Publisher: Elsevier  

ISSN Information: 0926-3373

Reactive adsorption of hydrogen sulfide on visible light photoactive zinc (hydr)oxide/graphite oxide and zinc (hydr)oxychloride/graphite oxide composites

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