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

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.