Z-Scheme Heterojunction of 3-Dimensional Hierarchical Bi3O4Cl/Bi5O7I for a Significant Enhancement in the Photocatalytic Degradation of Organic Pollutants (RhB and BPA)

Abstract

In this study, we report the synthesis of a 3-dimensional (3D) hierarchical Bi3O4Cl/Bi5O7I (BOC/BOI) heterostructure for the photocatalytic degradation of Rhodamine-B (RhB) dye and colorless Bisphenol-A (BPA) pollutant under visible light. The heterostructure was prepared using in situ solvothermal and calcination methods. BOC/BOI exhibits a 3D hierarchical structure constructed with thin nano-platelets. The photocatalytic performance of the BOC/BOI photocatalyst demonstrated that the degradation efficiencies of RhB and BPA were 97% and 92% after light illumination within 90 and 30 min, respectively. In comparison, bare BOC and BOI efficiencies were only 20% and 10% for RhB dye, respectively, and 2.3% and 37% for BPA aqueous pollutants, respectively. Moreover, radical trapping measurements indicated that •O2− and •OH radicals played prominent roles in RhB and BPA degradation into mineralization. Analysis of band structures and photochemical redox reactions of BOC/BOI revealed a Z-scheme charge transfer between BOC and BOI by an internal electric field formed at the interface. Therefore, the highly improved photocatalytic performance of the BOC/BOI heterostructure is attributed to the synergetic effects of large surface area, high visible-light absorption, and the enhanced separation and transport of photo-excited electron–hole pairs induced by the hierarchical and Z-scheme heterojunction of the BOC/BOI.

Synthesis of Co3O4 Nanoparticles-Decorated Bi12O17Cl2 Hierarchical Microspheres for Enhanced Photocatalytic Degradation of RhB and BPA

“…Figure A3 d shows the spectrum of Cl 2p, which contained diverse peaks at 198.58 and 200.139 eV, respectively. These can be attributed to Cl 2p 3/2 and Cl 2p 1/2 of the Cl − ions in the corresponding 20-Co 3 O 4 /BOC sample [ 41 ]. In Figure A3 e, the Co 2p peak of 20-Co 3 O 4 /BOC showed Co 2p 3/2 and Co 2p 1/2 spin-orbit doublets.…”

Calcination-Induced Oxygen Vacancies Enhancing the Photocatalytic Performance of a Recycled Bi2O3/BiOCl Heterojunction Nanosheet

“…The degradation rate ( D t ) of the pollutant was calculated using eq D t = ( c 0 − c t ) / c 0 × 100 % = ( A 0 − A t ) / A 0 × 100 % where c 0 is the concentration of RhB solution before light irradiation, c t is the concentration of RhB solution at moment t , A 0 is the absorbance of RhB solution before light irradiation, and A t is the absorbance of RhB solution at moment t .…”

“…The degradation rate (D t ) of the pollutant was calculated using eq 2 36 (2) where c 0 is the concentration of RhB solution before light irradiation, c t is the concentration of RhB solution at moment t, A 0 is the absorbance of RhB solution before light irradiation, and A t is the absorbance of RhB solution at moment t. 1e,f) present a clear crystal plane spacing, in which the lattice fringes with d-spacings of 0.33 and 0.74 nm correspond to the (120) plane of BO and the (001) plane of BOC, respectively. 37,38 It is apparent that the BBOC heterojunction was fabricated by the in situ construction of BOC on the BO surface.…”

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

“…By designing a proper heterojunction-type photocatalytic system, it is possible to isolate electrons and holes in separate locations, which in turn extends the lifetime of photogenerated carriers. 71,101,102 However, the design and construction of highly active heterojunction photocatalysts remain a challenging and new focus of research. In this section, various types of heterojunctions and other related junctions are discussed.…”

“…The Z-scheme heterojunction of Bi 2 Fe 4 O 9 /Bi 2 WO 6 Z was able to photodegrade 100% of RhB in 90 min, demonstrating significant catalytic activity. 129 Din et al 102 conducted a study on the Z-scheme heterojunction of the 3dimensional hierarchical Bi 3 O 4 Cl/Bi 5 O 7 I, using calcination and solvothermal methods. Figure 6a−d shows how Bi 3 O 4 Cl (BOC), Bi 5 O 7 I (BOI), and BOC/BOI-3 photocatalyst the decomposition of BPA and RhB dye in an aqueous solution under visible light.…”