Effect of heat treatment on photocatalytic activity of titania incorporated with carbon black for degradation of methyl orange

Abstract

In a previous study, the photocatalytic activity of titania (TiO₂) for the degradation of methyl orange was found to be significantly enhanced by the incorporation of carbon black (CB). This work aims to improve the catalyst activity further by changing the method of heat treatment and determining the optimal annealing temperature for the preparation of catalyst. The effect of annealing temperature on structure and activity of the prepared catalysts is also investigated. Experimental results reveal that the photocatalytic activities of both composite catalyst (TiO₂/CB) and bare TiO₂ annealed under N₂ flowing are higher than those of those calcined under atmospheric air. An optimal annealing temperature of 600°C maximizes the photocatalytic activity. Above this temperature, the activities of both catalysts decrease owing to a phase change and the growth of TiO₂ crystallites. The composite catalyst that was annealed at 600°C had a higher activity than Degussa P-25. © 2011 American Institute of Chemical Engineers Environ Prog, 2011