Alumina coating with TiO sub(2) and its effect on catalytic photodegradation of phenol and p -cresol

• Published in: Journal of chemical technology and biotechnology (1986) Vol. 91; no. 8; pp. 2211 - 2220
• Main Authors: Gomez, Claudia M, Angel, Gloria Del, Ramos-Ramirez, Esthela, Rangel-Vazquez, Israel, Gonzalez, Federico, Arrieta, Alma, Vazquez-Zavala, Armando, Bonilla-Sanchez, Adriana, Sanchez Cantu, M
• Format: Journal Article
• Language: English
• Published: 01-08-2016
• Subjects: Aluminum oxide; Anatase; Phenol; Photodegradation; Semiconductors; Surface area; Surface chemistry; Titanium dioxide
• ISSN: 0268-2575; 1097-4660
• DOI: 10.1002/jctb.5025

BACKGROUND This study is focused on the peptization of Boehmite and titanium alkoxide (modified sol-gel method) to obtain Al sub(2)O sub(3)-TiO sub(2) mixed oxides taking advantage of the physicochemical properties of TiO sub(2) and Al sub(2)O sub(3). TiO sub(2) is an important semiconductor and the most active photocatalyst. Al sub(2)O sub(3) is an insulator with high surface area and thermal, chemical and mechanical resistance. It is possible to produce high surface area materials, where TiO sub(2) is dispersed on the alumina surface for photodegradation of pollutants. RESULTS gamma -Al sub(2)O sub(3)- TiO sub(2) (5, 10 and 15 wt% TiO sub(2)) mixed oxides presented stabilization of the anatase phase. Rietveld studies showed incorporation of the Al super(3+) into the TiO sub(2) anatase and Ti super(4+) into the Al sub(2)O sub(3). They exhibit higher specific surface area than pure TiO sub(2). The TiO sub(2)-coated alumina surface with small TiO sub(2) particles produced a large number of active sites on the surface. The sample with 15 wt% of TiO sub(2) presented the highest photodegradation of p -cresol and phenol. CONCLUSION The addition of TiO sub(2) to the alumina improved the photoactivity of pure TiO sub(2) producing materials with higher surface area covered with TiO sub(2). Alumina delayed the recombination of photogenerated electron-hole pairs favoring the formation of highly reactive times OH radicals. The photodegradation of p -cresol and phenols increased with TiO sub(2) loading increase.