Silica-supported Au@hollow-SiO₂ particles with outstanding catalytic activity prepared via block copolymer template approach

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• 作者：Aruni Shajkumar^a ; Bhanu Nandan^b ; ^{nandan@textile.iitd.ac.in} ; Sunita Sanwaria^b ; Victoria Albrecht^a ; Marcin Libera^c ; Myong-Hoon Lee^d ; Gudrun Auffermann^e ; Manfred Stamm^a ; ^f ; ^{stamm@ipfdd.de} ; Andriy Horechyy^a ; ^{horechyy@ipfdd.de}
• 关键词：Nanocatalyst ; Yolk-shell ; Sol-gel ; Block copolymer micelles ; Template
• 刊名：Journal of Colloid and Interface Science
• 出版年：2017
• 出版时间：1 April 2017
• 年：2017
• 卷：491
• 期：Complete
• 页码：246-254
• 全文大小：1872 K
• 卷排序：491

文摘

Catalytically active Au@hollow-SiO2 particles embedded in porous silica support (Au@hollow-SiO2@PSS) were prepared by using spherical micelles from poly(styrene)-block-poly(4-vinyl pyridine) block copolymer as a sacrificial template. Drastic increase of the shell porosity was observed after pyrolytic removal of polymeric template because the stretched poly(4-vinyl pyridine) chains interpenetrating with silica shell acted as an effective porogen. The embedding of Au@hollow-SiO2 particles in porous silica support prevented their fusion during pyrolysis. The catalytic activity of Au@hollow-SiO2@PSS was investigated using a model reaction of catalytic reduction of 4-nitrophenol and reductive degradation of Congo red azo-dye. Significantly, to the best of our knowledge, Au@hollow-SiO2@PSS catalyst shows the highest activity among analogous systems reported till now in literature. Such high activity was attributed to the presence of multiple pores within silica shell of Au@hollow-SiO2 particles and easy accessibility of reagents to the catalytically active sites of the ligand-free gold surface through the porous silica support.