Photocatalytic degradations of three dyes with different chemical structures using ball-milled TiO2

Abstract

Cibacron Brilliant Red 3B-A (BR 3B-A) was photocatalytically degraded by TiO2 (A) ball milled (BM) at different milling time. TiO2 (A) BM for 2h (BM2 TiO2 (A)) showed the best photocatalytic degradation efficiency and was utilized to photcatalytically degrade commercial dyes of different chemical nature by breaking down the bond between chloride and the hydrocarbon chain. In the three dyes, i.e., Cibacron Brilliant Red BR 3B-A, Cibacron Brilliant Yellow 3G-P (BY 3G-P), and Astron Pink FG, chloride (Cl) is linked to carbon atom of different conformation. The experimental results suggested that the Cl connected to the aliphatic carbon is much easier and faster to disintegrate than the other two bonding with benzene and thiazine. Production rates of Cl− after 60-min irradiation were 99.7%, 78.1%, and 73.2%, respectively, for Astron Pink FG, BY 3G-P, and BR 3B-A. The changes in the structure characteristics, including the more amorphous surface morphology, the increased specific surface area, the growth in the percentage of high-index crystal faces, etc., were proposed to be the possible reasons for the promoted photocatalytic capability of BM2 TiO2 (A). Ball milling was found a handy approach to modify TiO2 (A) and boost catalytic degradation efficiency of dyes. This research lay out basis for application of photocatalyst in semiconductor industries.