Photocatalytic degradation of methylene blue and acetaldehyde by TiO2/glaze coated porous red clay tile

Autores: Yoo, S.J.|Lee, S.I.|Kwak, D.H.|Kim, K.G.|Hwang, K.J.|Lee, J.W.|Hwang, U.Y.|Park, H.S.|Kim, J.O.
Fuente: Korean journal of chemical engineering
25 (5), 1232-1238
2008

Nanosized TiO2 sol synthesized by sol-gel method was successfully coated oil the porous red clay tile (PRC tile) with micrometer sized pores. PRC tile was first coated with a low-firing glaze (glaze-coated PRC tile) and then TiO2 sol was coated oil tile ulaze layer. A low-fired glaze was prepared at various blending ratios with frit and feldspar, and a blending ratio glazed at 700 degrees C was selected as all Optimum Condition. Then TiO2 sol synthesized from TTIP was dip-coated oil the glazed layer (TiO2/glaze-coated PRC tile), and it was calcined again at 500 degrees C. Here, these optimum calcination temperatures were selected to derive a strong bonding by a partial sintering between TiO2 sol particles and glaze layer. Photocatalytic activity oil the TiO2/glaze-coated PRC tile was evaluated by the extent of photocatalytic degradation of methylene blue and acetaldehyde. Methylene blue With the high concentration of 150 mg/l on the Surface of TiO2/glaze-coated PRC tile w! as almost photodegraded within 5 hours under the condition of average UV intensity of 0.275 mW/cm(2), while no photodegradation reaction of methylene blue Occurred on the glaze-coated PRC tile without TiO2. Another photocatalytic activity was also evaluated by measuring the extent of photocatalytic degradation of gaseous acetaldehyde. The photodegradation efficiency in TiO2/glaze-coated PRC tile showed about 77% photocatalytic degradation of acetaldehyde from 45,480 mg/l to 10,536 mg/l after the UV irradiation of 14 hours, but only about 16% in the case of the glaze-coated PRC tile.