Chitosan-coated mesoporous microspheres of calcium silicate hydrate: environmentally friendly synthesis and application as a highly efficient adsorbent for heavy metal ions.
Chitosan-coated calcium silicate hydrate (CSH/chitosan) mesoporous microspheres formed by self-assembly of nanosheets have been synthesized in aqueous solution under ambient conditions without using any toxic surfactant or organic solvent. The method reported herein has advantages of simplicity, low cost and being environmentally friendly. The BET specific surface area of CSH/chitosan mesoporous microspheres is measured to be as high as ~356 m(2) g(-1), which is considerably high among calcium silicate materials. The as-prepared CSH/chitosan mesoporous microspheres are promising adsorbent and exhibit a quick and highly efficient adsorption behavior toward heavy metal ions of Ni(2+), Zn(2+), Cr(3+), Pb(2+) Cu(2+) and Cd(2+) in aqueous solution. The adsorption kinetics can be well fitted by the pseudo second-order model. The maximum adsorption amounts of Ni(2+), Zn(2+), Pb(2+), Cu(2+) and Cd(2+) on CSH/chitosan mesoporous microspheres are extremely high, which are 406.6, 400, 796, 425 and 578 mg/g, respectively. The CSH/chitosan adsorbent exhibits the highest affinity for Pb(2+) ions among five heavy metal ions. The adsorption capacities of the CSH/chitosan adsorbent toward heavy metal ions are relatively high compared with those reported in the literature.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Jing
J
Zhao
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China. Electronic address: y.j.zhu@mail.sic.ac.cn.
Ying-Jie
YJ
Zhu
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Jin
J
Wu
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Jian-Qiang
JQ
Zheng
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Xin-Yu
XY
Zhao
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Bing-Qiang
BQ
Lu
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Feng
F
Chen
D000327:Adsorption; D017610:Calcium Compounds / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D055772:Green Chemistry Technology / Q000191:economics; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019216:Metals, Heavy / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D016062:Porosity; D017640:Silicates / Q000737:chemistry*; D012824:Silicic Acid / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D017610:Calcium Compounds; D019216:Metals, Heavy; D017640:Silicates; D014874:Water Pollutants, Chemical; D012824:Silicic Acid; D048271:Chitosan; C031293:calcium silicate
Adsorption; Calcium silicate; Chitosan; Heavy metal; Mesoporous; Nanosheet