Efficient photocatalytic hybrid Ag/TiO2 nanodot arrays integrated into nanopatterned block copolymer thin films

Abstract

Well defined, ordered arrays of hybrid Ag/TiO₂ hetero nanodots were fabricated on solid substrates using amphiphilic poly(styrene-block-ethylene oxide) diblock copolymer (PS-b-PEO) micelles loaded with AgNO₃ and TiO₂ sol–gel precursors as templates. The inorganic precursors were selectively incorporated into PEO domains due to specific chemical affinity. The conversion of AgNO₃ to metallic Ag was induced by UV irradiation and confirmed by the presence of a surface plasmon band in the UV–vis absorbance spectra. The organic matrix has been removed by deep UV irradiation, leading to arrays of Ag/TiO₂ composite nanoparticles (NPs). The morphology and photocatalytic activities of the resulting hybrid nanoparticle arrays were studied. Markedly enhanced photocatalytic degradation of methylene blue has been observed for Ag/TiO₂ nanodot arrays compared with pure TiO₂ NP arrays.