MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Siyao Zhang,Shiyou Yu,Xin Wang,Yipeng Zhang,Zhenge Yue,Chenchen Li,Yongqiang Ma
Long-term consumption of honey containing ciprofloxacin (CIP) residues may harm human health. It is important to establish a sensitive and rapid CIP detection method. This study reports for the first time the development of an electrochemical sensor for rapid determination of CIP in honey, utilizing a MnO 2 /ZnO composites. Two types of ZnO with different morphologies were prepared, characterized, and compared for their electrocatalytic properties for CIP. The findings indicated that the rod-like ZnO had a better catalytic effect on CIP and was thus selected to combine with MnO 2 to form the composite material. Characterization of the resulting composite material was conducted, followed by an investigation of the electrochemical reaction of CIP on the electrode and optimization of the detection conditions of the sensors. The results indicate that the current value of CIP had a linear relationship with its concentration within the range of 0.5 to 120 µM, and the detection limit was 0.21 µM. The MnO 2 /ZnO/GCE sensor was applied to detect the CIP residues in honey samples, and the recoveries ranged from 95.3% to 97.2%. The results show that the composite material-modified sensor has good sensitivity and can enable rapid detection of CIP content in honey. Therefore, it has a potential application in detecting CIP residues in honey.
研究领域:
食品科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 20
·7429-7436
·
IF 5.287
Xiuquan Jia,Jiping Ma,Min Wang,Xiaofang Li,Jin Gao,Jie Xu
The tandem reaction is a growing field to yield important advances toward green and sustainable chemistry. Herein, we report a bifunctional manganese oxide catalyst with an interface binding redox phase (α-MnO2) and a basic phase (NaxMnO2). The molar ratio of NaOH/Mn plays a great role in the formation of α-MnO2/NaxMnO2. The sodium cation is essential for the formation of a basic NaxMnO2 phase while the potassium cation promotes the formation of a redox-active α-MnO2 phase. The interface structure of α-MnO2/NaxMnO2 geometrically favors the ammoxidation–Pinner tandem reaction to synthesize imidates in a 58–96% yield from aldehydes. Thus a phase collaborative effect is observed. In the ammoxidation process, the redox cycle of MnIV/MnIII is involved and the lattice oxygen in the α-MnO2 phase acts as an active oxygen species. The O–H in methanol is activated and dissociated on the basic sites of NaxMnO2 to the adsorbed methoxyl species to facilitate the Pinner synthesis. This approach bypasses the conventional synthesis of imidates, which suffer from harsh reaction conditions and the requirement for multiple steps.
研究领域:
催化化学
·
材料科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Qingwen Fan,Chaoyun Song,Peng Fu
In this study, we explored the effectiveness of enhancing microwave absorption capabilities of biomass-derived porous carbon by introducing MnO 2 through thermochemical techniques. The results showed that the MnO 2 -C exhibited higher values in both the real and imaginary parts of the dielectric constant compared to the Control, indicating that the addition of MnO 2 significantly enhanced the energy storage and dissipation capabilities. Although the magnetic loss properties of the composite were relatively weak, the increase in conductive and dielectric losses compensated for this aspect. Moreover, the loading of MnO 2 optimized the dielectric losses and promoted the reconstruction of charge, enabling MnO 2 -C to demonstrate superior microwave absorption performance, particularly in the high-frequency range. This is attributed to the multiple polarization mechanisms present in MnO 2 -C, including interfacial and dipolar polarization, which play a crucial role in enhancing dielectric losses. Additionally, a multilevel porous structure significantly enhanced the scattering and reflection of microwaves, further improving the absorption effectiveness. Consequently, these characteristics contribute to the MnO 2 -C achieving a minimum reflection loss value of −46.2 dB and an expanded effective absorption bandwidth. Overall, the MnO 2 -C composite, with its optimized electromagnetic properties and complex microstructure, provides valuable insights for the development of new, highly efficient microwave absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhenni Ding,Zilin Li,Yanhui Cao,Kaifeng Chen,Haiyan Zhuang,Jingjing Wang,Congshu Huang,Chi Ma,Dajiang Zheng
By depositing V 2 O 5 on precursor co-CoNi films with MnO 2 pretreatment layer using cyclic voltammetry (CV), a ternary electrochromic (EC) film with high performance and multicolor characteristic was obtained in this work. Compared with binary electrochromic film with deposition of V 2 O 5 on CoNi hydroxide films directly, the introduction of MnO 2 enhanced the cyclic stability significantly through formation of a more compact micro morphology and appearance of more active sites in this case. In addition, the ternary film presents higher optical modulation, less response time, higher coloring efficiency, better color memory ability, larger color range and faster electrochemical kinetics. The excellent electrochromic performance of the obtained film makes it possible to manufacture multicolor transparent EC devices, and demonstrates a promising application prospect in related fields.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Peiyan Liu,Meiri Wang,Jing Li,Hongtao Cui,Tao Zeng,Shubin Yang,Huan Wang,Yuanyuan Liu
Rechargeable aqueous Zn//MnO 2 batteries are the promising alternatives to lithium-ion batteries owing to their high safety, high energy density, low cost, and environmental friendliness. However, the unstable MnO 2 cathode causes poor practical energy density and serious capacity fading. To overcome this issue, herein, a unique 2D nanosheets self-supported 3D δ -MnO 2 microflower hierarchical architecture is rationally designed and synthesized by taking advantage of its microwave-absorbing characteristics. The 2D nanosheets with high surface area could expose numerous active sites for ions/electrons transfer. Also, the 3D assembled structure acting as building blocks would ensure structural stability for long-life cycles. Benefiting from these synergistic merits, the δ -MnO 2 microflowers deliver a high capacity of 287.6 mA h g −1 at 0.5 C, an excellent rate capability of 202.7 mA h g −1 at 5 C, and a superior cycling retention of 76.5% over 1000 cycles at 10 C. Furthermore, a storage mechanism of H + /Zn 2+ co-insertion accompanied by the deposition of zinc sulfate hydroxide hydrate is clarified by the aid of ex-situ XRD and SEM technologies. This work provides a new pathway for developing high capacity and long lifespan ZIBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 24
·9466-9471
·
IF 3.069
Ke Xing,Jia Ge,Wei-Xia Wang,Xin Geng,Xue-Ping Shen,Jin-Lu Tang,Ling-Bo Qu,Yuan-Qiang Sun,Zhao-Hui Li
Ascorbic acid plays a crucial role in biochemical processes as a scavenger for preventing oxidative damage. Herein, a sensitive and selective fluorescent biosensor for the detection of ascorbic acid was proposed based on green-emission fluorescent silicon nanoparticles (SiNPs) and bovine serum albumin (BSA) templated-MnO2 nanosheets. Green-emission fluorescent SiNPs have been synthesized by a facile one-pot reduction reaction at room temperature by using DAMO and 3-hydroxytyramine hydrochloride as the silicon source and the reactants, respectively. The fluorescence of the SiNPs could be effectively quenched by MnO2 nanosheets. When ascorbic acid is introduced, the MnO2 nanosheets are reduced to Mn2+ ions by ascorbic acid, resulting in the fluorescence recovery of SiNPs. This sensing system exhibits a good linear range for ascorbic acid detection from 1 to 400 μM with a detection limit of 0.102 μM. Meanwhile, the detection system also exhibits high selectivity against other possible co-existing species. The present sensor was successfully applied for the detection of ascorbic acid in a commercially available vitamin C supplement, suggesting this sensing system holds great potential in food safety and disease diagnosis.
研究领域:
生物化学
·
纳米技术
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
·
2022
·
IF 7.188
Bo Ge,Mingyang Li,Heyuan Li,Yuchao Li,Guina Ren,Wei Li
Environmental governance and clean water production are the challenges that human face. In this paper, the device composed of superhydrophobic layer, hydrophilic channel and photothermal conversion layer was fabricated. The superhydrophobic layer has a contact angle of 162°, which not only ensures the floating of the device, but also has the ability to selectively absorb non-water-soluble pollutants. In addition, the surface-loaded Bi 2 MoO 6 /Bi 2 O 3 photocatalyst can also degrade the water-soluble pollutants. After 4 cycles of photodegradation, the degradation efficiency was 92.6 %, demonstrating a stable degradation stability. The optimal content of MnO 2 (60 mg) was demonstrated by steam production rate experiments. The mechanical stability of superhydrophobic fabric, chemical stability of the MnO 2 , and photothermal stability were demonstrated. The assembled multifunctional devices can be used both for environmental treatment and for clean water production.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·
IF 2.072
Hongtao Guan,Jianbin Xie,Gang Chen,Yude Wang
One-dimensional α-MnO 2 nanorods were fabricated by using low-temperature water-bathing chemical precipitation method at 80 °C. The crystalline structures, morphological evolution process and microwave absorption properties were systematically investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and measurement of electromagnetic parameters. The results show that the morphological structures and electromagnetic properties have close relationship with the reaction time. With the prolonging of the treatment time, the as-synthesized products turn from microspheres constituted of tiny dendrites to nanorods with diameters of 20–30 nm and lengths up to 1–2 μm. The electromagnetic characterization shows that the dielectric constants and magnetic permeability values show decreasing trends with the increasing frequency, however, the dielectric and magnetic loss tangents all increase with frequency. The electromagnetic absorption properties of the products have close relationship with the morphologies and thicknesses of the samples. With a thickness of 3 mm, an absorbing peak value of −25 dB was achieved for the sample treated for 24 h. The microwave absorption properties of MnO 2 can be attributed mainly to interfacial polarization, space charge polarization and relaxation phenomena.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Yingfeng Qin,Gaojie Ye,Hao Liang,Ming Li,Jingjin Zhao
It is highly desirable to develop a simple, efficient and sensitive strategy for organophosphorus pesticides (OPs) in both environment pollution and human health. Herein, a novel amplified fluorescence polarization (FP) biosensor was established for highly sensitive detection of OPs using MnO 2 nanosheets as the signal enhancer. In this system, OPs can suppress the activity of acetylcholinesterase (AChE) efficiently, blocking the hydrolysis reaction of acetylthiocholine (ATCh) to generate thiocholine (TCh) by AChE. TCh can lead the decomposition of MnO 2 nanosheets to manganese ions. So, without the influence of TCh, MnO 2 nanosheets can maintain its original shape and form a stable complex with FAM-DNA, which greatly enhanced the FP signal. This method can tremendously improve the sensitivity of FP with a detection limit of 0.01 ng/mL for diazinon. In addition, it was also applicable to determine other four OPs and investigate the level of diazinon in real water samples. Consequently, the proposed approach provides a new promising platform for detection of OPs and is expected to be used in application of environmental monitoring.
研究领域:
环境科学
·
分析化学
·
生物传感
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2016
·Vol. 82
·期 1
·85-91
·
IF 1.473
Wang Li,Ma Wenle,Li Yanhong,Cui Hongtao
Abstract By a microwave-assisted hydrothermal method, nanoflower-like δ-MnO 2 was prepared for application in supercapacitors as electrode material. The characterization results indicated that the obtained architecture had the characteristics of electrode materials with high electrochemical performance. The flower architecture provided the channel surrounded by the nanosheets-like petals for the fast transfer of electrolyte ions. The thin thickness of nanosheets minimized the diffusion distance of electrolyte ions beneath the surface of material particles. The two advantages of the material guaranteed the high performance of material. It presented specific capacitance of 328 F g −1 at 5 mV s −1 in 1 M Na 2 SO 4 aqueous solution within a wide potential window of −0.5~1.0 V. During cycle stability test, the capacitance of material still remained 89% of its initial value after 5000 charge–discharge cycles. These results demonstrated that the nanoflower-like δ-MnO 2 could be applied as high performance electrode material. Graphical Abstract MnO 2 with different crystallographic forms and architectures was prepared by normal hydrothermal and microwave-assisted hydrothermal methods, respectively. The α-MnO 2 prepared by normal hydrothermal method presented architecture of nanobundles and the δ-MnO 2 prepared by microwave-assisted hydrothermal method exhibited architecture of nanoflower. The results of electrochemical measurements indicated that δ-MnO 2 had the higher performance than α-MnO 2 due to its unique nanoflower architecture.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2023
·Vol. 34
·期 25
·255602
·
IF 3.5
Chenji Xia,Yijia Luo,Xiaoqing Bin,Bowen Gao,Wenxiu Que
Combining the new two-dimensional conductive MXene with transition metal oxide to build composite structure is a promising path to improve the conductivity of metal oxide. However, a critical challenge still remains in how to achieve a good combination of MXene and metal oxide. Herein, we develop a facile hydrothermal route to synthesize the MnO2/Ti3C2Tx composite electrode for supercapacitors by synergistically coupling MnO2 nanowires with Ti3C2Tx MXene nanoflakes. Compared with the pure MnO2 electrode, the morphology of the MnO2/Ti3C2Tx composite electrode changes from nanowires to nanoflowers. Moreover, the overall conductivity and electrochemical performance of the composite electrode are greatly improved due to an addition of Ti3C2Tx MXene. The specific capacitance of the MnO2/Ti3C2Tx composite electrode achieves 210.8 F·g−1 at a scan rate of 2 mV·s−1, while that of the pure MnO2 electrode is only 55.2 F·g−1. Furthermore, the specific capacitance of the MnO2/Ti3C2Tx composite electrode still can remain at 97.2% even after 10 000 charge–discharge cycles, revealing an excellent cycle stability. The synthesis strategy of this work can pave the way for the research and practical application of the electrode materials for supercapacitors.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2020
·
IF 4.613
Xin Tan,Pu Zhang,Cuiying Ye,Yuanhong Min,Qianwen Li,Yi Wang
Development of new methods for dopamine (DA) assay has attracted continuous attention because it serves a vital role in clinical treatment of neurological diseases such as depression, schizophrenia, and Parkinson's disease. Herein, we design a carbon dots (CDs)-MnO 2 nanosheets platform for rapid and sensitive detection of DA in pharmaceutical products. The photoluminescence of CDs can be quenched by MnO 2 nanosheets via inner filter effect (IFE) because the absorption of MnO 2 nanosheets fully covered the excitation and emission bands of CDs. However, DA can transform MnO 2 nanosheets into Mn 2+ ions, resulting in the elimination of the IFE and recovery of the photoluminescent signal. This sensing platform shows a selective and sensitive response to DA in the range of 1–30 μM, with a detection limit of 100 nM. The presented IFE-based strategy gives a new insight on development of label-free, selective and sensitive optical methods for drug assay.
研究领域:
分析化学
·
生物医学
·
药物分析
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）