The Bi/Bi₂WO₆ heterojunction with stable interface contact and enhanced visible‐light photocatalytic activity for phenol and Cr(VI) removal

Abstract

BACKGROUND Semiconductor photocatalysis is the most promising green and energy‐saving technology for environmental remediation. Unfortunately, photocatalysis nanotechnology for its practical application is often challenged by the low capturing ability for visible light and use of expensive noble metals. In this work, we report the non‐noble Bi nanoparticles assembled on Bi2WO6 with enhanced visible‐light photocatalytic activity for decontamination of phenol and hexavalent chromium in water. RESULTS The 3% Bi/Bi2WO6 composite had the highest photocatalytic activity compared to pristine Bi2WO6, which could completely decompose phenol into small products within 120 min. More importantly, the Cr(VI) removal rate of the 3% Bi/Bi2WO6 catalyst in the presence of triethanolamine (TEOA, 2%) after irradiation for 12 min was up to 96.2%. CONCLUSIONS The improved photocatalytic performance could be due to the fast transfer of photogenerated charge carried by the formation of an anti‐barrier layer at the interface between metal Bi nanoparticles and the n‐type Bi2WO6 semiconductor; the enhancement of electron energy may be attributed to the localized surface plasmon resonance properties of Bi nanoparticles, as well as conspicuously strengthened and broad light‐capturing ability across the whole visible‐light range. This strategy could provide some inspiration for the design of other Bi‐based semiconductor heterostructures for decomposing harmful organic pollutants in wastewater and purifying hazardous gases in the air. © 2018 Society of Chemical Industry

Bi-Based Z-Scheme Nanomaterials for the Photocatalytic Degradation of Organic Dyes

“…For BISB, the diffraction peaks were widened, indicating that smaller particles and fragments were present in the product. Beside the peaks that could be attributed to the BiOI and Bi 2 S 3 structure, a weak peak at 27.17° could be assigned to hexagonal metallic Bi (ICSD: 44-1246), ,,− which indicated that BiOI, Bi 2 S 3 , and Bi coexisted in the BISB sample. The formation of metallic Bi nanoparticles might be due to the reductive nature of EtOH and MA at high temperatures …”

“…The condition of the surface elements was important for the performance of a photocatalyst, and these were further characterized via XPS. , As shown in Figure S1, Bi, I, O, and C were present in all of the samples. The magnified XPS analysis in Figure illustrated that the binding energies around 618.7 and 630.2 eV could be assigned to the characteristic of I 3d 5/2 and I 3d 3/2 of I – , indicating the presence of I – at the surface of all three samples. ,, In the O 1s region between 156–168 eV, overlapping peaks were observed; after multipeak fitting, three groups of peaks could be determined.…”

“…During the photodegradation process, various reactive species may be generated that are produced by the photogenerated holes and electrons, such as superoxide radicals (·O 2 – ), holes (h + ), and hydroxyl radicals (·OH) . To study the predominant active radicals existence in the photocatalyzation process, EDTA-2Na, BQ, and IPA were introduced into the catalyst-RhB solution as quenchers of h + , ·O 2 – , and ·OH, respectively. , The addition of different quenchers had different effects on the RhB photodegradation process, as shown in Figure D.…”

Simple Fabrication of Visible Light-Responsive Bi-BiOBr/BiPO4 Heterostructure with Enhanced Photocatalytic Activity

“…In addition, the effect of the heterostructure on the charge transfer resistance was also investigated, and EIS measurements were carried out to characterize the asprepared samples. It is well-accepted that the smaller arc diameter in Nyquist plots implies a lower resistance of the interfacial charge transfer in the electrode-electrolyte interface region on the surface of the electrode [49]. 3.7.…”

Recent Progress on Metallic Bismuth‐Based Photocatalysts: Synthesis, Construction, and Application in Water Purification

“…[ 91 ] Jia et al fabricated Bi/Bi 2 WO 6 composites via two‐step route. [ 92 ] First, flower‐like Bi 2 WO 6 microspheres were fabricated through solvothermal process. Subsequently, Bi nanoparticles were anchored on the Bi 2 WO 6 microspheres by a second solvothermal reaction route.…”