FeOOH Quantum Dot-Coupled Z-Scheme BiVO₄/g-C₃N₄ Heterojunction for Enhancing Photo-Fenton Reactions

Abstract

Herein, FeOOH quantum dots and a Z-scheme BiVO 4 /g-C 3 N 4 catalyst were coupled to obtain a Z-scheme heterojunction for photo-Fenton reactions to facilitate the transport of electrons and the generation of radicals. The obtained materials exhibited better visible light-driven photo-Fenton degradation of Rhodamine B, which is 22.06 times as high as pure BiVO 4 , 18.65 times as high as pure g-C 3 N 4 , and 3.44 times as high as BiVO 4 /g-C 3 N 4 , showing great potential in photo-Fenton degradation of pollutants. Moreover, the performance tests, radical capture experiments, and time-resolved fluorescence spectroscopy revealed that electron migration exists between the BiVO 4 /g-C 3 N 4 and FeOOH-QDs. This composite system accelerates the cycling of Fe 3+ /Fe 2+ during the photo-Fenton process, thus continuously generating reactive species (hydroxyl radicals (−OH) and superoxide radicals (−O 2 − )), leading to the rapid degradation of organic pollutants.

Porous In2O3 Hollow Tube Infused with g-C3N4 for CO2 Photocatalytic Reduction

“…The survey spectra of g-C 3 N 4 , IT, and CIT are shown in Figure S5. The O 1s spectrum of IT can be fitted to three peaks (Figure a), corresponding to lattice oxygen (529.45 eV), surface hydroxyls (531.61 eV), and adsorbed water (533.24 eV), respectively. , The strong peaks of surface hydroxyls and adsorbed water are attributed to the abundant oxygen vacancies in IT that can adsorb hydroxyl groups and water on the surface of IT. ,, Compared to IT, the hybrid CIT1 sample displays an increase in the hydroxyl peak and a decrease in the lattice oxygen peak (Figure a). This change may indicate that more oxygen vacancies were generated in the CIT1, potentially from reduction by cyanamide under a N 2 atmosphere during pyrolysis.…”

“…49,50 The strong peaks of surface hydroxyls and adsorbed water are attributed to the abundant oxygen vacancies in IT that can adsorb hydroxyl groups and water on the surface of IT. 43,51,52 Compared to IT, the hybrid CIT1 sample displays an increase in the hydroxyl peak and a decrease in the lattice oxygen peak (Figure 5a). This change may indicate that more oxygen vacancies were generated in the CIT1, potentially from reduction by cyanamide under a N 2 atmosphere during pyrolysis.…”

Heterostructured Photocatalytic Fabric Composed of Ag3PO4 Nanoparticle-Decorated NH2-MIL-88B (Co/Fe) Crystalline Wires for Rhodamine B Adsorption and Degradation

“…The construction of hybrid catalysts in the Z-scheme heterojunction has been demonstrated as an effective strategy for improving photocatalytic performance by efficient electron–hole separation and increased redox capability. In designing such heterojunctions, metal oxides, graphitic compounds, and MOFs are commonly accompanied. ,,− Implementing the Z-scheme requires the selection of photocatalysts with suitable band energy for efficient generation of •O 2 – and •OH – radicals. , Especially, the heterojunction composed of a bimetallic MOF is more complex to understand the catalytic mechanism and its applicability. , …”

Kinetic Comparison of Photocatalysis with the Photo-Fenton Process on the Removal of Tetracycline Using Bismuth-Modified Lanthanum Orthoferrite Nanostructures

“…Various studies can be found in the literature on the kinetics of photocatalytic and photo-Fenton degradation of pollutants. − Generally, photo-Fenton degradation follows pseudo-first-order kinetics, wherein the production of major reaction radicals gets accelerated due to the redox reaction of Fe or Fe-like species. Instead, the kinetics of photocatalysis can encompass a range of behaviors, including pseudo zero-order, pseudo-first-order, or pseudo-second-order reactions .…”

“…Instead, the kinetics of photocatalysis can encompass a range of behaviors, including pseudo zero-order, pseudo-first-order, or pseudo-second-order reactions . For example, FeOOH coupled with the heterostructure of BiVO 4 /GC 3 N 4 exhibited pseudo-first-order kinetic degradation of TC . However, Ma et al reported a second-order TCH degradation kinetics for Ag/TiO 2 catalyst .…”