Surface immobilization of β-cyclodextrin on hybrid silica and its fast adsorption performance of p-nitrophenol from the aqueous phase. Issue 103 (6th October 2015)

• Record Type: Journal Article
• Authors: Shen, Hai-Min; Zhu, Gong-Yuan; Yu, Wu-Bin; Wu, Hong-Ke; Ji, Hong-Bing; Shi, Hong-Xin; Zheng, Yi-Fan; She, Yuan-Bin
• Is Part Of: RSC advances. Volume 5:Issue 103(2015)
• Page Start: 84410
• Page End: 84422
• Publication Date: 2015-10-06
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra15592d
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Fast adsorption of p -nitrophenol was achieved through surface immobilization of β-cyclodextrin onto hybrid silica and maintenance of its hydrophobic cavity. Abstract : Renewable β-cyclodextrin (β-CD) was immobilized onto the surface of hybrid silica using ethylenediamine as linking groups to construct an adsorbent in water treatment (CD@Si), and the obtained CD@Si was characterized through FT-IR, XPS, EDX, contact angle measurement, TGA, solid-state 13 C NMR, SEM, and XRD analyses. The effect of initial pH, contact time on the adsorption performance of CD@Si for p -nitrophenol, and the adsorption kinetics, adsorption isotherms, adsorption thermodynamics, reusability and adsorption mechanism were investigated systematically, which indicate that the adsorption of p -nitrophenol onto CD@Si is a very fast process. The adsorption equilibrium can be reached in 15 s with an acceptable equilibrium adsorption capacity of 69.6 mg g −1 at pH 7.0, which is much faster than many reported adsorbents based on β-CD. The adsorption of p -nitrophenol onto CD@Si follows the pseudo-second-order model, obeys the Freundlich model, and is a feasible, spontaneous, and exothermic process which is more favorable at lower temperatures. And the formation of an inclusion complex and a hydrogen bond interaction are two origins of p -nitrophenol being adsorbed onto CD@Si. Additionally, CD@Si can be recycled and reused for at least five runs with an acceptable adsorption capacity, and is a very promising adsorbent for the fast adsorption of p -nitrophenol or its analogues from the aqueous phase. Additionally, this work also provides a strategy to increase the adsorption rate of adsorbents based on β-CD.