Anchoring Tailored Low-Index Faceted BiOBr Nanoplates onto TiO2 Nanorods to Enhance the Stability and Visible-Light-Driven Catalytic Activity

ACS Appl Mater Interfaces. 2017 May 17;9(19):16091-16102. doi: 10.1021/acsami.7b00433. Epub 2017 May 2.

Abstract

In this work, a fantastic one-dimensional (1D) BiOBr/TiO2 nanorod (NR) heterojunction composite was rationally proposed and designed from the perspective of molecular and interface engineering. The fabricated intimately connected interfacial heterojunction between two-dimensional BiOBr nanoplates and 1D TiO2 NRs acts as an interfacial nanochannel to promote efficient interfacial charge migration and separation of photogenerated electron-hole pairs. As a result, 1D BiOBr/TiO2 NR heterojunctions exhibited outstanding visible-light photocatalytic activities and sustained cycling performance. Under visible-light irradiation for 120 min, the reduction efficiency of Cr(VI) over the TB-2 sample (molar ratio: n(Ti)/n(Bi) = 2:1) is as high as 95.4% without adding any scavengers. Furthermore, the sample also shows excellent photodegradation activity of RhB with a much higher apparent rate constant of 0.49 min-1 and 88.5% total organic carbon removal ratio. Furthermore, the corresponding mechanism of enhanced photocatalytic activity is proposed according to comprehensively investigated results from photoluminescence spectroscopy, photoelectrochemical measurement analysis, and radical trapping experiments. This study provides an attractive avenue to design and fabricate highly efficient 1D NR heterojunction photocatalysts, which possessed a high application value in the field of environmental remediation, especially for wastewater purification.

Keywords: BiOBr; TiO2; heterojunction; nanorod; photoreduction.