Fabrication of fibrous amidoxime-functionalized mesoporous silica microsphere and its selectively adsorption property for Pb(2+) in aqueous solution.
Fibrous cyano-modified mesoporous SiO2 microspheres with specific surface area of ca. 300 m(2) g(-1) have been successfully fabricated respectively by in-situ synthesis and post-modification methods, based on the hydrolysis of ethyl silicate in the presence of (2-cyanoethyl)triethoxysilane at a certain condition. TEM observations show that the average diameters of the prepared fibrous cyano-modified SiO2 microspheres by these two methods are 68 and 211 nm, respectively. The N2 adsorption-desorption isotherms analysis on the fibrous SiO2 microspheres show sharp peaks in the 10-20 nm range. After the cyano groups transformed to amidoxime groups, the adsorption behavior of the fibrous amidoxime-functionalized mesoporous SiO2 microspheres for Fe(3+), Cu(2+), and Pb(2+) was investigated. The results show that the prepared SiO2 microspheres can selectively adsorb Pb(2+). The maximum equilibrium adsorption capacity for Pb(2+) could reach 284 mg/g. The desorption of Pb(2+) in 2M HNO3 completes within 60 min. The efficiency of the desorption is as high as 96.2%. This work provides the methods to prepare amidoxime-functionalized SiO2 microsphere with high specific surface area and total pore volume, which has the potential to be applied as an efficient adsorbent for specific heavy metal ions.
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
Yunyun
Y
Xie
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
Jie
J
Wang
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China. Electronic address: pstwmz@ustc.edu.cn.
Mozhen
M
Wang
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China. Electronic address: xwge@ustc.edu.cn.
Xuewu
X
Ge
D000327:Adsorption; D000577:Amides / Q000737:chemistry*; D007854:Lead / Q000302:isolation & purification*; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D010091:Oximes / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D000577:Amides; D010091:Oximes; D014874:Water Pollutants, Chemical; D007854:Lead; D012822:Silicon Dioxide
Adsorption; Amidoxime-functionalization; Fibrous mesoporous silica; Heavy metal ions