| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Nanomaterials | Wednesday Sessions |
| Session NM-WeP |
| Session: | Nanomaterials Poster Session |
| Presenter: | Ken-ichi Katsumata, Tokyo Institute of Technology, Japan |
| Authors: | K. Katsumata, Tokyo Institute of Technology, Japan M. Yamamoto, Tokyo Institute of Technology N. Matsushita, Tokyo Institute of Technology, Japan K. Okada, Tokyo Institute of Technology, Japan |
| Correspondent: | Click to Email |
TiO2 is actively studied as photocatalyst with environmental applications effected on photocatalytic performance by adjusting many factors in the structure. Recently, TiO2 monolith with unique three-dimensional structure has been reported. This is expected to various applications because the pore size and volume are able to control by the synthesis condition. The material, generally used as an adsorbent, extended the applications with visual light-sensitive. In this research, TiO2 monolith was synthesized with various heating temperatures, and its photocatalytic activity was investigated under visible light.
Porous TiO2 monolith was synthesized by sol-gel method. HCl, the aqueous solution of Polyethylen glycol (10000) in water and N-methyl formamide are added to Titanium propoxide stirring under ice-cooled condition. The gel is aged at 60oC for 24 h and heat-treated at 200oC for 2 h in stainless-steel autoclave with a Teflon inner liner. The wet gel plate thus obtained is washed by 1-propanol for 12 h, slowly drying for 1 week at room temperature and calcinated at 600, 700, 800 and 900oC for 5 h. Each of temperature rising rates is 1.0 oC/min. Each sample is immersed in the CuCl2 (moler rations of Cu/TiO2 = 1.0 × 10-3) aqueous solution at 90oC for 3 h. After washing by water and drying at 80oC, they are measured photocatalytic activity.
The samples heated at 600, 700, and 800oC had monolith structure, and the pore size and primary particle size depend on calcination temperature. However, the sample heated at 900oC did not maintain monolith structure. From the results of XRD patterns and Raman spectra, anatase was main phase at less than 700oC while rutile started to be observed at more than 700oC. It is expected that Cu(II)-grafted rutile monolith samples exhibit excellent photocatalytic activity under visiblelight. In addition, it was succeded that rutile nanotubes were formed on the surface of the monolith structures by solvothermal treatment. The monolith with nanotubes had very high specific surface area compared to the monolith without nanotubes. In detail, I will report the activity on the day.