2D/2D step-scheme α-Fe2O3/Bi2WO6 photocatalyst with efficient charge transfer for enhanced photo-Fenton catalytic activity

Wang, Wenliang; Zhao, Wenli; Zhang, Haochun; Dou, Xincheng; Shi, Haifeng

doi:10.1016/s1872-2067(20)63602-6

Cited by 148 publications

(34 citation statements)

References 68 publications

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“…In S-scheme photocatalyst, when an oxidation photocatalyst (OP) is coupled with a reduction photocatalyst (RP), an internal electric field (IEF) that directing from RP to OP is formed 42,44,45 . Then, when illuminated, the photoinduced holes in the RP recombine with the photoinduced electrons in the OP under the IEF [46][47][48][49] . Finally, the photogenerated carriers with strong redox ability are reserved, which explains the enhancement of the performance for photocatalysts perfectly [50][51][52][53][54][55] .…”

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confidence: 99%

Enhanced Photocatalytic H2O2 Production over Inverse Opal ZnO@ Polydopamine S-scheme Heterojunctions

Han¹,

Xu²,

Cheng³

et al. 2022

Acta Physico Chimica Sinica

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Photocatalytic H2O2 production is a sustainable and inexpensive process that requires water and gaseous O2 as raw materials and sunlight as the energy source. However, the slow kinetics of current photocatalysts limits its practical application. ZnO is commonly used as a photocatalytic material in the solar-to-chemical conversion, owing to its high electron mobility, nontoxicity, and relatively low cost. The adsorption capacity of H2O2 on the ZnO surface is low, which leads to the continuous production of H2O2. However, its photoresponse is limited to the ultraviolet (UV) region due to its wide bandgap (3.2 eV). Polydopamine (PDA) has emerged as an effective surface functionalization material in the field of photocatalysis due to its abundant functional groups. PDA can be strongly anchored onto the surface of a semiconducting photocatalyst through covalent and noncovalent bonds. The superior properties of PDA served as a motivation for this study. Herein, we prepare an inverse opal-structured porous PDA-modified ZnO (ZnO@PDA) photocatalyst by in situ self-polymerization of dopamine hydrochloride. The crystal structure, morphology, valency, stability, and energy band structure of photocatalysts are characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), electrochemical impedance spectroscopy (EIS), Mott-Schottky curve (MS), and electron paramagnetic resonance (EPR). The experimental results showed that electrons in PDA are transferred to ZnO upon contact, which results in an electric field at their interface in the direction from PDA to ZnO. The photoexcited electrons in the ZnO conduction bands flow into PDA, driven by the electric field and bent bands, and are recombined with the holes of the highest occupied molecular orbital of PDA, thereby exhibiting an S-scheme charge transfer. This unique S-scheme mechanism ensures effective electron/hole separation and preserves the strong redox ability of used photocarriers. In addition, the inverse opal structure of ZnO@PDA promotes light-harvesting due to the supposed "slow photon" effect, as well as Bragg diffraction and scattering. Moreover, the enhanced surface area provides a high adsorption capacity and increased active sites for photocatalytic reactions. Therefore, the resulting ZnO@PDA (0.03% (atomic fraction) PDA) exhibits the optimal H2O2 production performance (1011.4 μmol•L −1 •h −1 ), which is 4.4 and 8.9 times higher than pristine ZnO and PDA, respectively. The enhanced performance is ascribed to the improved light absorption, efficient charge separation, and strong redox capability of photocarriers in the S-scheme heterojunction. Therefore, this study provides a novel strategy for the design of inorganic/organic S-scheme heterojunctions for efficient photocatalytic H2O2 production.

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confidence: 99%

Enhanced Photocatalytic H2O2 Production over Inverse Opal ZnO@ Polydopamine S-scheme Heterojunctions

Han¹,

Xu²,

Cheng³

et al. 2022

Acta Physico Chimica Sinica

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“…As shown in Fig. 5a, H2O2 is too weak to oxidize TC to decompose (Wang et al 2020e;Wang et al 2021) (1.291×10 -4 min -1 ). The removal efficiency of 43.04% at 180 min in the presence of HCo@NC maybe caused by its hollow structure, and some TC molecules are adsorbed onto HCo@NC (5.67×10 -3 min -1 ).…”

Section: Figurementioning

confidence: 99%

ZIF-67 Derived Co Nanoparticles Embedded N-Doped Mesoporous Carbon Nanocages as an Active Heterogeneous Fenton Catalyst for the Degradation of Tetracycline

Wang

2021

Preprint

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Herein, the novel application of ZIF-67 derived HCo@NC as a highly active and stable catalyst for Fenton treatment of organic wastewater is discussed. The carbonization of the Cobalt based Zeolitic Imidazolate Framework-67 (ZIF-67) yielded of HCo@NC~700 nm shows a hollow structure inheriting the rhombic dodecahedron shape of the precusor ZIF-67. XPS analysis reveales the coexistence of Co2+ and Co0. The treatment of Tetracycline (TC) in HCo@NC catalyzed Fenton system indicates that hydroxyl radicals generated to oxidize TC to decompose, and the optimal condition is determined to be 0.71 mmol·L-1 H2O2 and 0.03 g·L-1 HCo@NC at pH 3 for the treatment of 15 mg·L-1 TC. H2O2 is catalyzed by HCo@NC to decompose to hydroxyl radicals for the degradation of TC, and the reaction mechanism is proposed.

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“…The electron paramagnetic resonance (EPR) spectra were also employed to determine the active radicals by using DMPO as trapping agent [54][55][56][57] . As depicted in Fig.…”

Section: Possible Photocatalytic Mechanismmentioning

confidence: 99%

A 0D/2D Bi4V2O11/g-C3N4 S-scheme Heterojunction with Rapid Interfacial Charges Migration for Photocatalytic Antibiotic Degradation

Zhou¹,

Li²,

Zhang³

et al. 2022

Acta Physico Chimica Sinica

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With the rapid development of industrial technology, a large number of organic pollutants are routinely released into the environment, which has caused serious problems. Semiconductor photocatalysis is an environmentally-friendly and effective method to degrade and remove typical pollutants, and photocatalysts play a key role in the application of this technology. Therefore, various semiconductor materials have been tried and used in the field of pollutant removal. Graphite carbon nitride (g-C3N4) has attracted great interest because of its two-dimensional layered structure and good visible light response range. Owing to a narrow bandgap, adjustable band structure, and high physicochemical stability, g-C3N4 absorbs wavelengths up to 450 nm in the visible spectrum, leading to an opportunity for visible-light photocatalytic performance. Nevertheless, there are still some drawbacks that limit the photocatalytic efficiency of g-C3N4 in the removal of antibiotics and dyes under visible light, such as the rapid recombination of photoinduced charges and the weak oxidation capacity of holes. To advance this promising photocatalytic material, multiple methods have been tried to optimize the electronic band structure of g-C3N4, such as doping with various elements, morphology control, and functional group modification. Recently, a novel type of Step-scheme (S-scheme) heterojunction composed of two n-type semiconductor photocatalysts has been proposed, which can utilize a more positive valance band and a more negative conduction band. It was demonstrated that the formation of S-scheme heterojunctions is a valid way to increase photocatalytic activity of g-C3N4. Herein, novel 0D/2D Bi4V2O11/g-C3N4 S-scheme heterojunctions were prepared by a simple in situ solvothermal growth method. The Bi4V2O11/g-C3N4 composites displayed a high photocatalytic activity through the removal of oxytetracycline (OTC) and Reactive Red 2. In particular, the BVCN-50 composite showed the highest degradation efficiency for OTC of 74.1% and for Reactive Red 2 of 84.2% with •O2 − as the primary active species.This highly improved photocatalytic performance can be ascribed to the generation of S-scheme heterojunctions, which provides for a high redox capacity of the heterojunction system (strong oxidative ability of Bi4V2O11 and strong reductive capacity of g-C3N4) and facilitates the space separation of photo-generated charges. Moreover, the surface plasmon resonance effect of metallic Bi 0 broadens the light utilization range of the heterojunction system. In addition, the possible degradation pathway and intermediates throughout the degradation process of OTC based on liquid chromatograph mass spectrometer (LC-MS) analysis were also studied. This work provides a novel tactic for the design and fabrication of g-C3N4-based S-scheme heterojunctions with enhanced photocatalytic performance.

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2D/2D step-scheme α-Fe2O3/Bi2WO6 photocatalyst with efficient charge transfer for enhanced photo-Fenton catalytic activity

Cited by 148 publications

References 68 publications

Enhanced Photocatalytic H<sub>2</sub>O<sub>2</sub> Production over Inverse Opal ZnO@ Polydopamine S-scheme Heterojunctions

Enhanced Photocatalytic H<sub>2</sub>O<sub>2</sub> Production over Inverse Opal ZnO@ Polydopamine S-scheme Heterojunctions

ZIF-67 Derived Co Nanoparticles Embedded N-Doped Mesoporous Carbon Nanocages as an Active Heterogeneous Fenton Catalyst for the Degradation of Tetracycline

A 0D/2D Bi<sub>4</sub>V<sub>2</sub>O<sub>11</sub>/g-C<sub>3</sub>N<sub>4</sub> S-scheme Heterojunction with Rapid Interfacial Charges Migration for Photocatalytic Antibiotic Degradation

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