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

• Published in: Journal of colloid and interface science Vol. 491; pp. 246 - 254
• Main Authors: Shajkumar, Aruni, Nandan, Bhanu, Sanwaria, Sunita, Albrecht, Victoria, Libera, Marcin, Lee, Myong-Hoon, Auffermann, Gudrun, Stamm, Manfred, Horechyy, Andriy
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-04-2017
• Subjects: Block copolymer micelles; Nanocatalyst; Sol-gel; Template; Yolk-shell; Block copolymer micelles; Nanocatalyst; Yolk-shell; Sol-gel; Template
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2016.12.051

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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.