Rational design of 3D/2D In 2 O 3 nanocube/ZnIn 2 S 4 nanosheet heterojunction photocatalyst with large-area "high-speed channels" for photocatalytic oxidation of 2,4-dichlorophenol under visible light.

We have rationally designed and fabricated of "face-to-face" 3D/2D In ₂ O ₃ nanocube/ZnIn ₂ S ₄ nanosheet heterojunction by growing ZnIn ₂ S ₄ nanosheets on the surfaces of In ₂ O ₃ cubes as photocatalysts for 2,4-dichlorophenol (2,4-DCP) degradation under visible light. Herein, the unique 3D/2D In ₂ O ₃ nanocube/ZnIn ₂ S ₄ nanosheet hierarchical structure not only exposes far more abundant heterojunction interface active sites compared to 3D/0D In ₂ O ₃ nanocube/ZnIn ₂ S ₄ nanoparticle, but also produces numbers of compact high-speed nanochannels in the junctions, which significantly promotes the separation and migration of photogenerated carriers. Profiting by structural and compositional advantages, the optimized 3D/2D ZnIn ₂ S ₄ -In ₂ O ₃ photocatalyst shows excellent photocatalytic activity and stability in the degradation of 2,4-DCP, which is 1.85, 2.60, 3.02 and 3.54-fold higher than that of 3D/0D ZnIn ₂ S ₄ -In ₂ O ₃ , ZnIn ₂ S ₄ nanosheet, ZnIn ₂ S ₄ nanoparticle and In ₂ O ₃ , respectively. Meanwhile, the main active species (·O ₂ ^- , ·OH and h ⁺ ) produced in the photodegradation process were determined and the intermediates and degradation mechanism were studied in detail. Besides, the application on the removal of 2,4-DCP in natural water and actual wastewaters by 3D/2D ZnIn ₂ S ₄ -In ₂ O ₃ also have been studied. This work provides a new strategy for efficiently optimize the advantages of binary nano-architectures to effectively degrade phenolic pollutants in the environment.
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