Visible Light‐Driven BiOBr/Bi2S3@CeMOF Heterostructured Hybrid with Extremely Efficient Photocatalytic Reduction Performance of Nitrophenols: Modeling and Optimization

Abstract The one‐pot facile solvothermal process was applied to designed BiOBr/Bi 2 S 3 heterostructured microspheres. The hierarchical BiOBr/Bi 2 S 3 photocatalyst is integrating by solid‐state adding of cerium based metal‐organic frameworks (CeMOF) using ball mill to fabricate a novel BiOBr/Bi 2 S 3 @CeMOF. The synthesized photocatalysts were examined by XRD (X‐Ray diffraction), Raman, FTIR (Fourier transform infrared spectroscopy), XPS (X‐Ray photoelectron spectroscopy), FESEM (field emission transmission electron microscopy), FETEM (field emission scanning electron microscopy), UV‐Vis DRS (ultraviolet‐visible diffuse reflectance), PL (Photoluminescence), and transient photocurrent analysis. The as‐prepared BiOBr/Bi 2 S 3 @CeMOF photomaterial displays considerably enhanced photocatalytic activity for reduction of 4‐nitrophenol (4NP) to 4‐aminophenol (4AP) compared with the pristine BiOBr and BiOBr/Bi 2 S 3 composite under the irradiation of visible light. The promising BiOBr/Bi 2 S 3 @CeMOF photocatalyst exhibit the highest photoreduction efficiency of 4NP along with the highest reaction rate ( K ) (R: 98 %; K : 3.91 min −1 ) compared with the other as‐prepared materials such as CeMOF (R:38 %; 0.23 min −1 ), BiOBr (R: 48 %; K : 0.65 min −1 ), Bi 2 S 3 (R:68 %;0.92 min −1 ), and BiOBr/Bi 2 S 3 (R: 75 %; K : 1.38 min −1 ) photocatalysts after 30 min of visible light irradiation. The boosted photocatalytic efficiency is attributed to creating the heterojunction at the interface of BiOBr/Bi 2 S 3 @CeMOF, which can powerfully facilitate the separation of the photogenerated carriers. After that, the Box‐Behnken design was applied to indicate the optimum condition for the reduction of 4NP under the effect of different variables (e. g., the concentration of NP (A:), pH (B), and concentration of NaBH 4 (C). At the optimum condition (A: 14.5μmol L −1 , B: 5, and C: 0.88 mol L −1 ), the photoreduction efficiency (%) of the 4NP is 99.7 %. BiOBr/Bi 2 S 3 @CeMOF catalyst exhibits excellent photoreduction stability over five successive reaction runs.