Analytical Sciences

Evaluation of the Water-treatment Ability of Silica-doped Titanium Dioxide-coated Glass Plates Using a Cationic Coupling Reagent Based on a Flow Analytical System

Tsuyoshi SUGITA,* Masanobu MORI,* Akinori MASE,* Shin-nosuke NOGUCHI,* Toru TOKUTOME,* Kengo FUJII,* Chisato HARA,** Kenji KATAYAMA,*** Shinji IWAMOTO,* and Hideyuki ITABASHI*

*Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
**Kyoritsu Chemical-Check Lab., Corp., 5-37-11 Den-enchofu, Ota, Tokyo 145-0071, Japan
***Department of Applied Chemistry, Chuo University, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551, Japan

In this study, a photocatalytic plate bound to highly dispersible silica-doped titanium dioxide (SiT) on a trimethoxysilyl-propyldiethylenetriamine (dien)-coated glass plate (dien-plate) was newly synthesized, and was evaluated by a flow analytical (FA) system, which consists of a photocatalytic reactor and a spectrophotometer, to continuously monitor the absorbance of tested chemicals. The method was not required to collect any sample solution at a constant period. The SiT–dien-plate facilitated the photodecomposition of methylene blue (MB) and indigo carmine (InC) in aqueous solutions. Notably, MB was quantitatively photo-decomposed following 18 h of UV-light irradiation, related to the electrostatic adsorption of surface-bound particles. A water-treatment ability of visible-light-responsive vanadium-modified nitrogen/silica co-doped titanium dioxide fixed on the dien-plate was also evaluated by the FA system. It clarified to decompose MB and InC under visible-light irradiation. Finally, the decomposition of a humic substance dissolved from Middle West China peaty soils by the SiT–dien-plate under UV-irradiation was assessed as applying the FA system with a photocatalytic plate.

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