Study On Adsorption Performances Of Amino-functionalized SBA-15for Cr³⁺and Zn²⁺

Using triblock copolymer Pluronic P123as a structure-directing agent, tetraethylorthosilicate （TEOS） as silica sources, SBA-15with well-ordered mesostructure has beenhydrothermally synthesized. Amino-functionalized SBA-15materials was obtained using3-aminopropyl triethoxy silane（APTES） as functionalization agent by post-synthesis methods.The influence of the ratio of APTES to SBA-15on the adsorption has been studied. Theresults show the obtained NH2-SBA-15showed very high adsorption when the best ratio ofAPTES to SBA-15was0.004mol/g.The synthesized amino-functionalized SBA-15materials were characterized by methods ofinstrumental analysis, such as low-angle X-ray diffraction （XRD）, Transmission electronmicroscopy （TEM）, Scanning electron microscopy （SEM）, Infrared spectroscopy （IR）, N2adsorption desorption isotherms and so on. The SEM images reveals that the morphology ofAPTS-SBA-15consists of rod-shaped particles aggregated into bundles. TEM images showsthat APTS-SBA-15exhibits a highly ordered hexagonal pore system, similar to SBA-15.SBA-15functionalized with3-aminopropyltrimethoxy-silane was used as adsorbent forCr³⁺and Zn²⁺ions in aqueous solution. The adsorption capacity changed with increasingtemperature and time, initial ion concentration and pH. The optimum adsorption conditionswere that the initial concentration of Cr³⁺solution was220mg/L, pH=4.5, adsorption timewas6h and adsorption temperature60℃. The obtained NH2-SBA-15showed very highadsorption of26.29mg/g under the optimum conditions. The optimum adsorption conditionswere that the initial concentration of Zn²⁺solution was200mg/L, pH=4.5, adsorption timewas6h and adsorption temperature60℃. The obtained NH2-SBA-15showed very highadsorption of24.09mg/g under the optimum conditions. Subjected to remove toxic heavymetal ions in aqueous solution, which should be attributed to the strong complexationreactions between metal ions and grafted NH2groups.