Preparation and photocatalytic activity of eccentric Au–titania core–shell nanoparticles by block copolymer templates

Abstract

A novel route for a preparation of eccentric Au–titania core–shell nanoparticles using gold nanoparticles (AuNPs) with block copolymer shells as a template is reported. AuNPs with poly(2-vinyl pyridine)-block-poly(ethylene oxide) (PVP-b-PEO) block copolymer shells are first prepared by UV irradiation of the solution of PVP-b-PEO/HAuCl₄ complexes. Then the sol–gel reaction of titanium tetra-isopropoxide (TTIP) selectively on the surfaces of AuNPs leads to Au–titania core–shell composite nanoparticles. The eccentric Au–titania core–shell nanoparticles are obtained from the Au–titania core–shell composite nanoparticles by removal of organic interlayer by UV treatment. Photocatalytic activities of the resulting eccentric core–shell nanoparticles are investigated in terms of the degradation of methylene blue (MB). The results show that the eccentric core–shell structures endow the catalyst with greatly enhanced photocatalytic activity.