Indexed by:期刊论文

Date of Publication:2011-10-21

Journal:JOURNAL OF MATERIALS CHEMISTRY

Included Journals:Scopus、SCIE、EI

Volume:21

Issue:39

Page Number:15567-15574

ISSN No.:0959-9428

Abstract:Hybrid hierarchically porous silica adsorbents were simply fabricated by the sol-gel method and modified with thiol or sulfonic groups. These materials with pores on both micrometre and nanometre scales exhibit a satisfactorily adsorptive property to various pollutants in water, including heavy metal ions (Hg(2+), Cd(2+), Pb(2+), Cu(2+), Ag(+) and CrO(4)(2-)) and organic compounds (dyes, biogenic amines, pesticides and amino acids). The thiol functionalized hierarchically porous silica micro-foam (SH-HSM), which has a low thiol content (0.66 mmol g(-1)), shows significantly high adsorption capability to Hg(2+) (140.1 mg g(-1)) in particular. Then sulfonic acid-functionalized adsorbent (SO(3)H-HSM) was obtained through direct oxidization of SH-HSM by H(2)O(2) without destruction of the hierarchical structure. It was found that SO(3)H-HSM could effectively remove organic compounds with positive charge in solution through electrostatic interactions. The adsorption capability of SO(3)H-HSM for some basic dyes, such as fuchsin basic, could reach approximately 1145.2 mg g(-1). The mixture of SH-HSM and SO(3)H-HSM showed good purifying capacity to simulate multicomponent wastewater, containing different inorganic and organic chemicals. The removal rate for any of the pollutants was more than 90%, and could even reach 100% for metal ions and dyes. The strong adsorption ability of these porous adsorbents may be due to the interwoven meso-and macroporous structures which can increase mass transport and easier accessibility for pollutants to the active sites.