Editors: Ellingson R
Publisher: Materials Research Society
Volume number: 945
Abstract: Photo-induced reduction of viologen (V) with surface-modified TiO 2 was investigated (Scheme 1). In order to enhance the reduction of V, cavities for molecular recognition of V were fabricated on the surface of TiO2 through sol-gel imprinting method. Once TiO2 had recognition site for the oxidized viologen (V2+) on its surface, it was distinguishable through shape or charge differences from the reduced viologen (V+) and facilitated the inclusion of target molecule resulted in enhancement of the photoinduced reduction efficiently. The formation of viologen monocation radicals from three different types of viologens (methyl-, hexyl-, and pentacarboxyl-) was monitored spectrophotometrically with time in the presence of the imprinted TiO2 and also using a blank. Higher conversion was observed in every case of imprinted TiO2 compared with the blank one indicating that recognition was not an ill-defined surface effect but involved the bipyridinium part of the viologen. ® 2006 Materials Research Society
Template and target information: viologen, V