Removal of F- from Water Using Templated Mesoporous Carbon Modified with Hydrated Zirconium Oxide

Three types of MgO-templated mesoporous carbon possessing different specific surface area and pore size distribution were modified with hydrated zirconium oxide (ZrO2 center dot xH(2)O) to prepare fluoride anion (F-) adsorbents. ZrO2 center dot xH(2)O was synthesized through the auto-hydrolysis of zirconium oxychloride (ZrOCl2) in water under the coexistence of mesoporous carbon. X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS) indicated that the mesoporous carbon surfaces were coated with mainly amorphous ZrO2 center dot xH(2)O. Capabilities of aqueous F- removal of the prepared adsorbents and the unmodified mesoporous carbons were compared. The F- uptake by the prepared adsorbents was larger than that observed using unmodified carbons, indicating that the F- adsorption capacity was improved through the ZrO2 center dot xH(2)O coating. Moreover, the adsorption capability was found to depend on the pore size of the mesoporous carbons. The F- uptake decreased as pH of F- solution increased. Protonation and deprotonation of ZrO2 were found to affect the F- adsorption.