A Bifunctional BiOBr/ZIF-8/ZnO Photocatalyst with Rich Oxygen Vacancy for Enhanced Wastewater Treatment and H2O2 Generation

Abstract

Photocatalytic technology is considered an ideal approach for clean energy conversion and environmental pollution applications. In this work, a bifunctional BiOBr/ZIF-8/ZnO photocatalyst was proposed for removing phenols in wastewater and generating hydrogen peroxide. Insights from scanning electron microscopy measurements revealed the well-dispersion of ZIF-8/ZnO was on the BiOBr layer, which could effectively prevent agglomeration of ZIF-8 and facilitate the separation of carriers. In addition, the optimal H2O2 yield of the BiOBr/ZIF-8/ZnO sample could reach 116 mmol·L−1·g−1 within 2 h, much higher than that of pure BiOBr (with the value of 82 mmol·L−1·g−1). The optimal BiOBr/ZIF-8/ZnO sample could also remove 90% of the phenol or bisphenol A in 2 h, and its kinetic constants were 3.8 times and 2.3 times that of pure BiOBr, respectively. Based on the analysis of the various experimental characterizations, the photocatalytic mechanism of the S-scheme BiOBr/ZIF-8/ZnO composite for the degradation of phenolic pollutants and generation of H2O2 was proposed. The formation of the heterojunction and the oxygen vacancy work together to significantly improve its photocatalytic efficiency. In addition, the BiOBr/ZIF-8/ZnO catalyst has a certain impact on the degradation of phenol in actual wastewater, providing a way to effectively remove refractory pollutants and generate H2O2 in actual water.

Bismuth-Based Z-Scheme Heterojunction Photocatalysts for Remediation of Contaminated Water

“…Furthermore, in the recent year a Z-scheme heterojunction of BiOBr/ZIF-8/ZnO photocatalyst was prepared for the removal of phenols in wastewater. The result demonstrates that the ideal BiOBr/ZIF-8/ZnO photocatalysts were shown to have the degradation efficiency of 90% of the removal of phenol or bisphenol in 2 h, with kinetic constants that were 3.8 and 2.3 times higher, respectively, than those of pure BiOBr …”

“…The result demonstrates that the ideal BiOBr/ZIF-8/ZnO photocatalysts were shown to have the degradation efficiency of 90% of the removal of phenol or bisphenol in 2 h, with kinetic constants that were 3.8 and 2.3 times higher, respectively, than those of pure BiOBr. 165 Endocrine-Disrupting Compound Degradation. It is believed that the endocrine system in the body is regulated by hormones through the endocrine system.…”

Carbonaceous Material Modified MoO2 Nanospheres with Oxygen Vacancies for Enhanced Visible-Light Photocatalytic Oxidative Coupling of Benzylamine

“…It has been accepted that the bulk defects are the recombination centers of photo-induced electrons and holes, which is unfavorable for photocatalytic reaction [ 25 , 26 ]. In comparison, surface OVs play an important role not only in the extension of the photo response, but also in increasing the charge separation efficiency [ 27 , 28 , 29 ]. Semiconductor photocatalysts with rich surface OVs, such as TiO 2 , BiO 2 , MoO 3 , WO 3 , ZnO and so on, have been extensively reported [ 16 , 30 , 31 , 32 , 33 ].…”

“…Generally, these methods always involved high temperature or production of hydrogen [ 36 ]. Therefore, it makes sense to develop a simple and effective method to incorporate surface OVs into photocatalysts [ 27 , 38 ]. In situ introduction of carbonaceous precursors can trigger a reconstruction of the oxide surface and the formation of nanocomposites with interfacial disordered regions.…”

The Solid-State Synthesis of BiOIO3 Nanoplates with Boosted Photocatalytic Degradation Ability for Organic Contaminants

“…Layered bismuth-based photocatalysts characterized by (Bi 2 O 2 ) 2+ layers and interlayer ions or polyhedra as crystal structures, such as BiOX (X = Cl, Br, I), Bi 2 O 2 CO 3 , and Bi 2 XO 6 (X = W, Mo), have been widely researched because their conduction bands have a positive potential, which has powerful oxidation ability for pollutants, and their special layered structure is conducive to the separation of carriers [6][7][8]. BiOIO 3 is a novel Aurivillius-type layered bismuth-based compound; its crystal structure consists of (Bi 2 O 2 ) 2+ and (IO 3 ) − layers stacked alternately along the c-axis direction [9,10].…”