In Situ Construction of Dye-Sensitized BiOCl/Rutile-TiO 2 Nanorod Heterojunctions with Highly Enhanced Photocatalytic Activity for Treating Persistent Organic Pollutants.

The construction of efficient and stable heterojunction photocatalysts with a controllable close contact interface and visible-light response is a challenging research topic in the field of photocatalysis. Herein, a series of BiOCl/rutile-TiO ₂ (R-TiO ₂ ) nanorod heterojunctions were constructed using R-TiO ₂ nanorods as supporting frameworks followed by selective adsorption of Cl ^- on R-TiO ₂ (110) facets and in situ growth of BiOCl on the surface of TiO ₂ nanorods. The strong affinity of rhodamine B (RhB) as a photosensitizer for BiOCl allowed the prepared BiOCl/R-TiO ₂ heterojunctions to work efficiently under visible-light irradiation. The dye-sensitized BiOCl/R-TiO ₂ nanorod heterojunctions displayed promising photocatalytic performance for simultaneously treating RhB and the persistent organic pollutant 2- sec -butyl-4,6-dinitrophenol (DNBP). The highly enhanced photodegradation activity of the BiOCl/R-TiO ₂ system was mainly attributed to the efficient RhB-photosensitization effect, the enhanced heterojunction effect, and the suitable conduction band match between BiOCl and R-TiO ₂ , which facilitated electron transfer from the excited RhB to the catalyst surface and charge separation across the BiOCl/R-TiO ₂ interface, thus promoting the formation of ^• O ₂ ^- and h ⁺ as dominant active species in the reaction system for degradation of pollutants. The results demonstrate that the construction of a dye-sensitized BiOCl/R-TiO ₂ heterojunction system is an effective strategy for improving the photocatalytic potential.