CARBON
·
2014
·
IF 6.16
Ying Guo,Baoxin Li
This paper reports for the first time the chemiluminescence (CL) of luminol in the absence of added oxidant with carbon dots (CDs) as the catalyst. By means of CL spectra, UV–vis spectra, electron spin resonance spectra, Fourier transform infrared and X-ray photoelectron spectra, the possible CL reaction mechanism is proposed. The CL luminophor was still 3-aminophthalate, the CL enhancement of luminol system was supposed to originate from the intrinsic catalytic activity of CDs, which can efficiently catalyze the decomposition of dissolved oxygen to generate superoxide radical anion in luminol solution. Then, the resulting superoxide radical anion reacted with luminol to cause CL emission. Furthermore, the effects of size and surface states on the catalytic activity of CDs were investigated. The results suggested that the catalytic activity of CDs are mainly affected by the surface states, and the size of CDs display little influence on the catalytic activity of CDs. Therefore, the catalytic activity of CDs can be tuned by modulating functional groups on the surface of CDs, which sheds new light on the characteristic of CDs.
研究领域:
分析化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Yan Zhuang,Jingfei Luan
Novel peony-like InOOH photocatalyst was firstly obtained with the help of glycerol in the solvothermal process, whose optimal proportion of glycerol was determined to be 25%. X-ray diffraction, scanning electron microscope, X-ray energy dispersion spectrum, transmission electron microscopy, X-ray photoelectron spectroscopy and UV–visible diffusion reflectance spectrum were obtained and analyzed to reveal the structure, morphology, physical and chemical properties of synthesized samples. The results indicated that the synthesized InOOH was orthorhombic structure with the peony-like morphologies, whose average particle size was 2–5 µm approximately. The band-gap of the peony-like InOOH was estimated to be 3.65 eV. The photocatalytic activities of the samples were investigated by degrading norfloxacin under UV-light irradiation, which followed the first-order reaction kinetics. The degradation efficiency of peony-like InOOH could reach up to 98.84%. And the first order kinetic constant of peony-like InOOH was 0.01519 min −1 , which was about 4.8 times or 1.7 times than that of hexagram-like InOOH or InOOH nanosheet. The peony-like InOOH showed the most superior photocatalytic performance compared with hexagram-like InOOH and InOOH nanosheet, which originated from its high separation efficiency and low recombination rate of photoproduction electron-hole pairs. The reduction of total organic carbon revealed the mineralization of norfloxacin during the photocatalytic process. Finally, O 2 − radicals were proved to be main reactive species during the degradation process of norfloxacin. Furthermore, the degradation pathway and the degradation mechanism of norfloxacin with peony-like InOOH as catalyst were discussed in detail.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Yang Guo,Juhong Zhan,Gang Yu,Yujue Wang
Due to the fast reaction of superoxide radical ( O 2 • − ) with ozone (O 3 ), it has been suggested that O 2 • − is present at very low concentrations during ozonation. Therefore, while O 2 • − has been considered a critical chain carrier for promoting O 3 decomposition to hydroxyl radicals (•OH), the direct reactions of O 2 • − with micropollutants have been assumed to be insignificant during ozonation. In this study, we monitored the exposures of O 3 , •OH, and O 2 • − by following the depletion of O 3 , p -chlorobenzoic acid ( p CBA, as •OH probe), and tetrachloromethane (CCl 4 , as O 2 • − probe) during ozonation of various water matrices (surface water, groundwater, and secondary wastewater effluent). For a given water matrix, the ratio between •OH and O 3 exposures (R ct ), O 2 • − and O 3 exposures (R SO ), as well as O 2 • − and •OH exposures (R SH ) remained almost constant over the entire reaction time. This suggests that during ozonation, the ratios between the transient concentrations of •OH and O 3 , O 2 • − and O 3 , and O 2 • − and •OH were also constant and equaled to the R ct , R SO , and R SH , respectively. Based on the O 3 , •OH, and O 2 • − exposures observed during ozonation, a chemical kinetic model was proposed to simulate the abatement of ten ozone-resistant micropollutants in the three water matrices by ozonation. The results indicate that due to the higher concentrations of O 2 • − than •OH (R SH = ~5–8), the reactions with O 2 • − played a non-negligible or even dominant role in the abatement of some micropollutants that have similar or higher O 2 • − reactivity than •OH reactivity (e.g., tetrachloroethylene, chloroform, and PFOA). Compared with the previous model that neglected the contribution of O 2 • − to micropollutant abatement, the proposed model more accurately simulated the abatement efficiencies of the test micropollutants during ozonation. These results indicate that the proposed model can provide a useful tool for the generalized prediction of micropollutant abatement by ozonation.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2022
·
IF 3.841
Mengyu Zhu,Jun Lu,Linchang Dong,Shuheng Hu,Shuchuan Peng,Chengzhu Zhu
The possible photochemical transformation pathways of chlorophenols (2, 6-dichlorophenol and 2-chlorophenol) with superoxide anion radical (O 2 ·− ) were studied by steady-state irradiation and 355 nm laser flash photolysis technique. O 2 ·− was generated by irradiating riboflavin O 2 -saturated solution with an UVA light (maximum at 365 nm). The steady-state experimental results suggested that the transformation efficiency of chlorophenols improved with the increase of the initial riboflavin concentration and solution initial pH value, while the increase of chlorophenols concentration would inhibit the photochemical reaction. The second-order rate constant of the reaction of O 2 ·− with 2, 6-DCP phenoxyl radical (2, 6-DCP · ) and 2-CP phenoxyl radical (2-CP · ) were determined as (8.39 ± 0.99) × 10 9 L mol −1 s −1 and (5.17 ± 0.68) × 10 9 L mol −1 s −1 by laser flash photolysis techniques, respectively. The transformation of chlorophenols was accompanied by the formation of Cl − induced by superoxide radicals after the mixed riboflavin and chlorophenols solution with UVA irradiation. The main conversion products of the reaction between 2, 6-DCP and O 2 ·− were identified by GC-MS, as 2-chlorophenol, 2, 6-dichloro-1, 4-benzoquinone, 2, 6-dichloro-hydroquinone and 3-chlorocatechol, while 2-CP with O 2 ·− was 2-chloro-1, 4-benzoquinone, 2-chlorohydroquinone and phenol, respectively. The transformation pathways of 2, 6-DCP and 2-CP with O 2 ·− were also proposed.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Jin Yang,Yan Cao,Naidong Zhang
A method was developed that used hydroxylamine hydrochloride as a probe in a superoxide anion radical-generating visible light system for determining superoxide anion radicals. An Azure I solution with hydroxylamine hydrochloride was illuminated, after which a ferric iron solution was added to the sample solution and the remaining hydroxylamine hydrochloride in solution reduced from ferric to ferrous ions. Then, 1,10-phenanthroline solution was added and spectrophotometrically measured at 510 nm, which indirectly indicated the hydroxylamine hydrochloride content. The yields of superoxide anion radicals were indirectly expressed by the hydroxylamine hydrochloride decrement. Under optimal experimental conditions, the linear range was 0.0–1.5 × 10 −5 M and the limit of detection and limit of quantification were obtained to be 8.37 × 10 −7 and 2.54 × 10 −6 M with an R 2 of 0.9993. The method was simple and feasible and could be used for the stable measurement of superoxide anion radicals produced by photosensitizers that produce color under acidic conditions in visible light systems.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2014
·Vol. 21
·期 11
·1-8
·
IF 1.897
Ran Xiaoqi,Yi Shixiong,Liang Liefeng,Yang Xiao
The effect of oxygen on photodegradation of π-conjugated aromatic poly(1,3,4-oxadiazole)s (POD) was studied in detail. The results obtained by tensile test, UV-spectra and ATR-FTIR revealed that the oxygen was indispensable during photodegradation of POD. The occurrence of photodegradation of POD must be combination of UV exposure and oxygen simultaneously. The state of oxygen during photodegradation of POD was investigated by nitrotetrazolium blue chloride (NBT) method. The result illustrated that the oxygen was transformed into superoxide anion radical through accepting one electron during UV exposure. Results of tensile tests and UV-spectra further proved that the superoxide anion radical could combine with excited POD to form an unstable product that lead to occurrence of photodegradation. Singlet oxygen was also investigated and the result showed that POD appeared to be stable to singlet oxygen.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER INTERNATIONAL
·
2018
·Vol. 67
·期 9
·1282-1290
·
IF 2.352
Xiao Yang,Lian Duan,Xiaoqi Ran
A donor–acceptor conjugated-type polymer, poly(thiophene-1,3,4-oxadiazole) (PThOD), was synthesized by one-step polycondensation in polyphosphoric acid. PThOD was confirmed and characterized using Fourier transform infrared spectra, thermogravimetric analysis, X-ray diffraction and UV-visible spectra. The UV-visible spectra showed that PThOD could absorb not only in the whole ultraviolet range from 200 to 400 nm but also in the visible light range up to 500 nm. Considering the conjugated structure of PThOD, studies were carried out of its performance for the photocatalytic degradation of various dyes, such as methyl orange, methylene blue, rhodamine B and reactive brilliant blue (RBB), under medium-pressure Hg light source irradiation. The results showed that PThOD was an effective photocatalyst, which could degrade the four types of dye solution. Besides, visible light was also used to investigate the degradation of RBB, and the results showed that RBB could be degraded as well, though the efficiency was not as high as using the Hg lamp. The superoxide anion radical (O 2 •− ), which is one of the reactive oxide species, was detected using the nitrotetrazolium blue chloride method and considered to play a key role in photodegradation of dyes. Moreover, various scavengers were also used to further prove the function of − . Furthermore, it was found that degradation rate could be changed by adding H + , which might be attributed to a change of adsorption capacity of PThOD. Finally, the reusability of PThOD as photocatalyst was investigated. The results indicated that the reusability efficiency of PThOD was excellent even after ten continuous rounds of use. © 2018 Society of Chemical Industry
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2019
·
IF 3.218
Huanhuan Zhang,Xuan Cai,Hongli Zhao,Wenqian Sun,Zhenxing Wang,Minbo Lan
Developing nanomaterials as alternatives of enzymes is of great significance to realize qualification and quantitation of superoxide anion (O 2 − ), which has been proved to play a crucial role in physiological condition. In this work, a novel electrochemical catalyst of cobalt nanoparticle doped porous cubic carbon (Co-PCC) was prepared through the calcination of zeolitic imidazolate framework-67 (ZIF-67), which was obtained from one-step synthesis. Then Co-PCC was used to construct enzyme-free electrochemical sensor for the detection of O 2 − . The response of H 2 O 2 , though much lower than that of O 2 − , was also caught by the Co-PCC/SPCE. The fabricated sensor exhibited obvious response towards O 2 − in the range of 0.8–76.8 μM (R 2 = 0.997) with a high sensitivity of 3.59 × 10 −4 mA μM −1 cm −2 and a limit of detection of 0.41 μM (S/N = 3). In addition, the proposed sensor can be used to detect O 2 − released from SK-BR-3 cells, which makes it possible to monitor the dynamic change of O 2 − in living cells.
研究领域:
生物化学
·
材料科学
·
医学检测
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Shuchang Liu,Xi Yuan,Zhewen Shao,Kexin Xiang,Wenfang Huang,Hailin Tian,Feng Hong,Yingping Huang
Presently, the hydroxyl radical oxidation mechanism is widely acknowledged for the degradation of organic pollutants based on hydrodynamic cavitation technology. The presence and production mechanism of other potential reactive oxygen species (ROS) in the cavitation systems are still unclear. In this paper, singlet oxygen ( 1 O 2 ) and superoxide radical (·O 2 − ) were selected as the target ROS, and their generation rules and mechanism in vortex-based hydrodynamic cavitation (VBHC) were analyzed. Computational fluid dynamics (CFD) were used to simulate and analyze the intensity characteristics of VBHC, and the relationship between the generation of ROS and cavitation intensity was thoroughly revealed. The results show that the operating conditions of the device have a significant and complicated influence on the generation of 1 O 2 and ·O 2 − . When the inlet pressure reaches to 4.5 bar, it is more favorable for the generation of 1 O 2 and ·O 2 − comparing with those lower pressure. However, higher temperature (45 °C) and aeration rate (15 (L/min)/L) do not always have positive effect on the 1 O 2 and ·O 2 − productions, and their optimal parameters need to be analyzed in combination with the inlet pressure. Through quenching experiments, it is found that 1 O 2 is completely transformed from ·O 2 − , and ·O 2 − comes from the transformation of hydroxyl radicals and dissolved oxygen. Higher cavitation intensity is captured and shown more disperse in the vortex cavitation region, which is consistent with the larger production and stronger diffusion of 1 O 2 and ·O 2 − . This paper shed light to the generation mechanism of 1 O 2 and ·O 2 − in VBHC reactors and the relationship with cavitation intensity. The conclusion provides new ideas for the research of effective ROS in hydrodynamic cavitation process.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Lei Ye,Yu Huang,Lingzi Zhang,Xin Li,Bo Zhang,Xuezhen Yang,Jianhua Luo,Hongping Liu,Xiaoping Zhang,Chuan Song,Zonghua Ao,Caihong Shen,Wei Tan,Xiaolin Li
An acidic polysaccharose (YL-D2N2) was isolated from crude polysaccharides of pink Auricularia cornea and characterized for its structural and antioxidant properties. YL-D2N2 consists of fucose, galactose, glucose, xylose, mannose and glucuronic acid in a molar ratio of 0.85: 1.50: 4.44: 27.52: 46.56: 19.13. It has a number-average molecular weight of about 52.811 kDa and a weight-average molecular weight of about 135.457 kDa. Structural characterization showed that YL-D2N2 consists of nine residues (Xyl p -(1→, Glc p A-(1→, →2)-Xyl p -(1→, →3)-Gal p -(1→, →3)-Man p -(1→, →4)-Glc p A-(1→, →2,3)-Man p -(1→, →3,4)-Glc p -(1→, →3,6)-Man p -(1→), with a backbone of →3)-β-D-Man p -(1→, →2,3)-α-D-Man p -(1→, →3,6)-α-D-Man p -(1 → and side chains containing β-D-Xyl p -(1 → and α-D-Glc p A-(1→. Notably, YL-D2N2 exhibits significant radical scavenging activity for superoxide anions, reaching 50.82 ± 0.64 % at a concentration of 3.2 mg/mL. Overall, YL-D2N2 exhibits a unique chemical structure and specialized applications for targeting superoxide anion radicals, providing valuable insights for further exploration of its structure-activity relationship.
研究领域:
生物化学
·
药理学
·
真菌学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Huiping Wang,Qixiang Wang,Qiwei Wang,Wenjuan Dong,Yang Liu,Qin Hu,Xiuli Song,Shaomin Shuang,Chuan Dong,Xiaojuan Gong
Bacterial infections have become a considerable obstacle to public health due to the emergence of antibiotic resistance. Herein, we rationally developed a novel and attractive nitrogen-doped carbon nanodots (N-CNDs) as efficient metal-free artificial nanozymes that synergistically and efficiently inhibit bacterial survival by inheriting the bacteriostatic ability of tea polyphenols and light-triggered oxidase-like catalytic activity . The excellent oxidase-mimicking activity exhibited by N-CNDs in the light was mediated by superoxide radicals (•O 2 − ) with a high maximum reaction rate (1.59 μM⋅s −1 ) and a low Michaelis constant (0.421 mM). Furthermore, the constructed N-CNDs-based nanozyme was demonstrated to serve as a complex biomaterial platform for efficient sterilization by light-driven oxygen molecule generation of •O 2 − . Remarkably, the inherent antibacterial ability of N-CNDs can effectively inhibit both Gram-positive and Gram-negative bacteria, particularly against Gram-positive S. aureus at a minimum inhibitory concentration (MIC 90 ) of 375 μg⋅mL −1 . The inactivation rates of N-CNDs alone agsinst E. coli and S. aureus were 59.72% and 37.15%, respectively. However, the inactivation rates of E. coli and S. aureus by N-CNDs achieved by light were as high as 97.91% and 80.02%, respectively. Encouragingly, a two-way ANOVA revealed that the concentration of N-CNDs and the duration of light exposure had a synergistic effect on antibacterial behavior, which provided favorable conditions for the sustained eradication of exposed bacteria. This synergistic strategy for bacterial eradication based on a novel metal-free carbon-based nanozyme provides a powerful and feasible approach for bacterial contamination management in food safety and environmental protection.
研究领域:
生物医学
·
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Yunfei Zhang,Jinhong Fan,Bo Yang,Wutao Huang,Luming Ma
In this study, the commercial zero-valent copper (ZVC) was investigated to activate the molecular oxygen (O 2 ) for the degradation of acetaminophen (ACT). 50 mg/L ACT could be completely decomposed within 4 h in the ZVC/air system at initial pH 3.0. The H 2 O 2 , hydroxyl radical ( OH) and superoxide anion radical ( O 2 − ) were identified as the main reactive oxygen species (ROSs) generated in the above reaction; however, only OH caused the decomposition and mineralization of ACT in the copper-catalyzed O 2 activation process. In addition, the in-situ generated Cu + from ZVC dissolution not only activated O 2 to produce H 2 O 2 , but also initiated the decomposition of H 2 O 2 to generate OH. Meanwhile, the H 2 O 2 could also be partly decomposed into O 2 − , which served as a mediator for copper cycling by reduction of Cu 2+ to Cu + in the ZVC/air system. Therefore, OH could be continuously generated; and then ACT was effectively degraded. Additionally, the effect of solution pH and the dosage of ZVC were also investigated. As a result, this study indicated the key behavior of the O 2 − during Cu–catalyzed activation of O 2 , which further improved the understanding of O 2 activation mechanism by zero-valent metals.
研究领域:
环境科学
·
化学动力学
·
催化反应
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）