The resourcefulness of p(4-VP) cryogels as template for in situ nanoparticle preparation of various metals and their use in H2 production, nitro compound reduction and dye degradation
Yükleniyor...
Tarih
2015
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Poly(4-vinylpyridine) (p(4-VP)) cryogels were synthesized under cryogenic conditions (T=-18 degrees C) and were converted to positively charged forms by modifying with different alkyl dihalides of variable chain lengths such as 1,2-dibromoethane (1,2 BE), 1,4-dibromobutane (1,4 BB), 1,6-dibromohexane (1,6 BH), and 1,8-dibromooctane (1,8 BO). The chemical structure of synthesized supermacroporous 1,4 BB-p(4-VP) cryogels were confirmed by FT-IR spectroscopy. The 1,4 BB modified-poly(4-vinylpyridine) (1,4 BB-p(4-VP)) cryogels were used as template for in situ metal nanoparticle preparation as 1,4 BB-p(4-VP)-M (M: Co, Ni, Cu, and Fe) using chloride salts of Co, Ni, Cu, and Fe in ethanol. These metal-nanoparticle macroporous cryogel composites were employed in H-2 generation from hydrolysis of sodium borohydride (NaBH4). Metal nanoparticles embedded 1,4 BB-p(4-VP)-M were visualized by TEM, and thermal behavior of 1,4 BB-p(4-VP) cryogels were done by thermogravimetric analyzer (TGA). The metal content of 1,4 BB-p(4-VP)-M was estimated via atomic absorption spectroscopy (AAS). Multiple metal salt loading and reduction cycles were performed for 1,4 BB-p(4-VP) cryogels to increase the amount of contained Co. The activation energies, enthalpy, and entropy for NaBH4 hydrolysis catalyzed by 1,4 BB-p(4-VP)-Co cryogel composites were determined as 47.6 kJ (mol)(-1), 46.2 kJ (mol K)(-1), and 146.91 (mol K)(-1), respectively. The cryogel network embedded with Co, Ni, Cu, and Fe nanoparticles was also used as a catalyst in the reduction of 4-nitrophenol (4-NP) in an aqueous solution in excess amount of NaBH4. Furthermore, the Cu metal nanoparticle-containing 1,4 BB-p(4-VP) cryogel was utilized in the degradation of methylene blue (MB). (C) 2014 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Super porous cryogel/hydrogel composite catalyst, Environmentally benign catalysts, H-2 production, Nitro compound reduction, Dye degradation
Kaynak
Applied Catalysis B-Environmental
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
166
