Enhancement of photocatalytic efficiency by in situ fabrication of BiOBr/BiVO4 surface junctions


Wenzong Yin , Xiang Sun , Wenzhong Wang

DOI:10.1016/j.jes.2016.12.024

Received September 28, 2016,Revised January 05, 2017, Accepted , Available online October 23, 2017

Volume 60,2017,Pages 78-83

Surface junctions between BiOBr and BiVO4 were synthesized. The BiOBr/BiVO4 with 1 wt.% of BiOBr exhibited the highest photocatalytic activity in the degradation of RhB under visible-light irradiation. It was found that the highly efficient adsorption of RhB molecules via the electrostatic attraction between Br? and cationic \N(Et)2 group played a key role for the high photocatalytic activities of BiOBr/BiVO4. This efficient adsorption promoted the N-deethylation of RhB and thus accelerated the photocatalytic degradation of RhB. Moreover, the metal-to-metal charge transfer (MMCT) mechanism was proposed, which revealed the concrete path paved with Bi–O–Bi chains for the carrier migration in BiOBr/ BiVO4. The interaction between photoexcited RhB* and the Bi3+ in BiVO4 provided the driving force for the migration of photo-generated carriers along the Bi–O–Bi chains. This work has not only demonstrated the important role of efficient adsorption in the photocatalytic degradation of organic contaminants, but also developed a facile strategy to improve the efficiency of photocatalysts.

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