Catalysis Science & Technology
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2021
·Vol. 11
·期 24
·7963-7972
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IF 6.119
Anyu Liu,Jianqiang Hu,Jiale He,Xinyue Huang,Na Hu,Yuqin Li,Qingling Huang,Shien Guo,Xin Liu,Zhen Yang,Yong Zhou,Zhigang Zou
O-doped g-C3N4/In2S3 hierarchical heterostructures with a direct Z-scheme mechanism were devised and constructed simply via loading In2S3 nanoflakes on the surface of O-doped g-C3N4 (OCN) hierarchical structures, in situ, employing pre-obtained OCN (prepared by condensation of oxalic acid and urea) and indium(III) dimethyldithiocarbamate (In(dedc)3) as precursors. Analyses of the energy band structure, density functional theory (DFT) computations and DMPO-ESR spin-trapping experiments demonstrate that the formation of a perfect heterointerface with a staggered alignment of band edges between OCN and In2S3 (IS), owing to their close contact, enables photoexcited carriers to migrate via a Z-scheme route, which can maintain the higher reduction and oxidation capability of electrons and holes, respectively. Furthermore, the Z-scheme OCN/IS heterostructures efficaciously facilitate the separation of photogenerated electrons and holes, as demonstrated using PL spectra, transient photocurrent densities and electrochemical impedance spectra (EIS). These lead to the enhanced photocatalytic activity towards reducing Cr(VI) into Cr(III). Besides, the integration of OCN with IS can enhance the responsiveness to visible light based on the results of UV-vis DRS, thereby inducing the formation of more electrons and holes,and also contributing to the improvement of the photocatalytic activity for Cr(VI) reduction. In consequence, all the pre-prepared OCN/IS hybrids possess markedly improved photocatalytic activities for Cr(VI) reduction, relative to pure OCN and pristine IS under visible light (λ > 420 nm) illumination. With the increase in the In(dedc)3 to OCN mass ratio (R), the photocatalytic activities of these OCN/IS hybrids increase first and then decrease. The sample with an optimum R of 0.9 (OCN/IS-0.9) can remove nearly 100% of Cr(VI) after 40 min of illumination, being superior to most of g-C3N4-based and IS-based photocatalysts. Its reaction rate constant for Cr(VI) photoreduction (0.08947 min−1) is 56.7 fold and 8.8 fold higher than that of pure OCN (0.00155 min−1) and pristine IS (0.00913 min−1), respectively. This work affords a deep understanding on designing preeminent Z-scheme photocatalysts towards the degradation of Cr(VI) under visible-light irradiation.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 11
·1826
·
IF 5.719
Jiahui Zhang,Yan Jing,Peng Zhang,Benhua Xu
Herein, oxygen-doped g-C3N4quantum dots (OCNQDs) were fabricated through sintering and ultrasonic-assisted liquid-phase exfoliation methods. The obtained OCNQDs with uniform size show high crystalline quality, and the average diameter is 6.7 ± 0.5 nm. Furthermore, the OCNQDs display excellent fluorescence properties, good water solubility, and excellent photo stability. The OCNQDs as fluorescence probe show high sensitivity and selectivity to Fe3+ions. Furthermore, the fluorescent OCNQDs are applied for live cell imaging and Fe3+ions detecting in living cells with low cytotoxicity, good biocompatibility, and high permeability. Overall, the fluorescent OCNQDs fabricated in this work can be promising candidates for a range of chemical sensors and bioimaging applications.Keywords:oxygen-doped g-C3N4quantum dots;fluorescence;metal ion detection;bioimaging
研究领域:
材料科学与工程
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生物医学工程
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化学
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DOI
PubMed
高影响因子
Catalysts
·
2019
·Vol. 10
·期 1
·6
·
IF 3.444
Jia Huang,Gang Nie,Yaobin Ding
To develop highly efficient heterogeneous photocatalysts for the activation of dissolved oxygen is very interesting in the field of green degradation of organic pollutants. In the paper, oxygen atom doped g-C3N4(O-g-C3N4) was prepared via a facile chemical oxidation of g-C3N4by peroxymonosulfate. X-ray photoelectron spectroscopy analysis suggests the oxidative treatment of g-C3N4by peroxymonosulfate evidently increased atomic percentage of oxygen on O-g-C3N4surface to 6.9% as compared with 1.8% for g-C3N4. Meanwhile, the doped oxygen atom mainly existed as carbonyl and carboxyl groups. Optical characterization indicates the introduction of oxygen improved the response of O-g-C3N4to visible light, and more obviously, separation of photo-generated h+-e−. 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) probe measurement indicates the formation of O2•−was dramatically enhanced through activation of dioxygen by photo-generated electrons in the O-g-C3N4photocatalytic system. Through high performance liquid chromatography (HPLC) and Liquid chromatography–mass spectrometry (LC-MS) analysis, it was found rhodamine B (RhB) photocatalytic degradation by O-g-C3N4followed step by step N-deethylation reaction pathways induced by the formed O2•−, rather than the non-selective decomposition of the chromophore in RhB by other radicals, such as hydroxyl radicals. This study provides a facile method to develop oxygen atom doped g-C3N4photocatalyst, and also clarifies its photocatalytic activation mechanism of molecular oxygen for N-deethylation reaction of RhB.Keywords:photocatalysis;oxygen doped g-C3N4;activation of dioxygen;superoxide radicals;selective N-deethylation of rhodamine B
研究领域:
环境科学
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材料科学
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光化学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2025
·
IF 7.2
Yibing Feng,Kun Qiao,Xiaohan Jiang,Huiling Ji,Jiang Meng,Jigang Wang
A photocatalysis–self-Fenton system (PSFs) offers a viable solution to the continuous hydrogen peroxide (H 2 O 2 ) dosing and insufficient Fe 2 + regeneration challenges in conventional Fenton chemistry. An oxygen-doped g-C 3 N 4 microrod (OCNT)-based PSFs was synthesized via a facile oxalic acid-mediated supramolecular self-assembly route, enabling efficient pollutant degradation. In situ H 2 O 2 production was achieved through a two-electron oxygen reduction reaction (2e − -ORR), with photogenerated electrons accelerating Fe 2+ /Fe 3+ cycling and enhancing H 2 O 2 utilization. The system exhibited an apparent rate constant of 0.071 min −1 for tetracycline (TC) removal, 12.2- and 4.2-fold higher than pristine g-C 3 N 4 and a photo-Fenton system, respectively. Density functional theory (DFT) calculations and experimental results indicated that oxygen heteroatom doping increased the molecular dipole moment and optimized the band structure, while the one-dimensional microrod morphology exposed abundant active sites. These synergistic effects facilitated charge-carrier separation, improved interfacial mass transfer, and promoted the two-electron oxygen-reduction pathway, thereby accelerating Fe 2+ /Fe 3+ cycling and hole oxidation. The platform demonstrated broad pH adaptability, strong anti-interference capability, and long-term operational stability. This work provides an effective strategy for on-site H 2 O 2 generation and utilization in photocatalytic–Fenton systems for the degradation of organic contaminants.
研究领域:
环境化学
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材料科学
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催化
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水处理技术
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物理化学
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纳米技术
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产品关联
DOI
高影响因子
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