Nanoscale
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2016
·Vol. 8
·期 27
·13414-13421
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IF 7.76
Yang Xu,Xi Chen,Ran Chai,Chengfen Xing,Huanrong Li,Xue-Bo Yin
A novel magnetic/fluorometric bimodal sensor was built from carbon dots (CDs) and MnO2. The resulting sensor was sensitive to glutathione (GSH), leading to apparent enhancement of magnetic resonance (MR) and fluorescence signals along with visual changes. The bimodal detection strategy is based on the decomposition of the CDs–MnO2 through a redox reaction between GSH and MnO2. This process causes the transformation from non-MR-active MnO2 to MR-active Mn2+, and is accompanied by fluorescence restoration of CDs. Compared with a range of other CDs, the polyethylenimine (PEI) passivated CDs (denoted as pCDs) were suitable for detection due to their positive surface potential. Cross-validation between MR and fluorescence provided detailed information regarding the MnO2 reduction process, and revealed the three distinct stages of the redox process. Thus, the design of a CD-based sensor for the magnetic/fluorometric bimodal detection of GSH was emphasized for the first time. This platform showed a detection limit of 0.6 μM with a linear range of 1–200 μM in the fluorescence mode, while the MR mode exhibited a linear range of 5–200 μM and a GSH detection limit of 2.8 μM with a visible change being observed rapidly at 1 μM in the MR images. Furthermore, the introduction of the MR mode allowed the biothiols to be easily identified. The integration of CD fluorescence with an MR response was demonstrated to be promising for providing detailed information and discriminating power, and therefore extend the application of CDs in sensing and imaging.
研究领域:
分析化学
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生物化学
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材料科学
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DOI
PubMed
高影响因子
LANGMUIR
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2018
·
IF 3.789
Yu Zhang,Qing Li,Jiwei Liu,Wenbin You,Fang Fang,Min Wang,Renchao Che
The Fe2O3@C@MnO2@C (FCMC) nanocomposites containing spindle-like Fe2O3 as a core and MnO2 nanoflakes as a sandwiched shell and double carbon layers have been successfully prepared by a facile method. As anode materials of lithium ion batteries (LIBs), the cycling stability, rate performance, and conductivity of the prepared FCMC nanocomposites are far beyond those of the carbon-free Fe2O3@MnO2 (FM) nanocomposites. The hierarchical structure with double layers of carbon effectively enhances the ion conductivity and electrochemical performance of transitional metal oxides, indicating that carbon in FCMC played an important role during lithium ion storage. The initial discharge/charge capacity of the FCMC electrode reaches as high as 1240.2/1215.9 mAh g–1, and the discharge capacity is over 1000 mAh g–1 at 500 mA g–1 after 50 cycles. Additionally, the unique hierarchical structural characteristic with double layers of green carbon with a high degree of graphitization makes FCMC an excellent catalyst in removing methylene blue (MB) dye from solution with H2O2 under a slight heating with the degradation time as short as 10 min. Our work presents a new perspective on carbon modified multilayer core–shell oxide structure, which can be applied to many fields such as energy storage and catalyst.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2021
·Vol. 413
·期 19
·4887-4894
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IF 4.157
Zhang Luwei,Xin Fuli,Cai Zhixiong,Zhao Hong,Zhang Xiaolong,Yao Cuiping
Azodicarbonamide (ADA), as a dough conditioner food additive in flour, can be turned into toxic biurea and semicarbazide after high temperature processing. Hence, the using of ADA in food material should be strictly controlled, and the detection of ADA is very important for consumers’ safety and health. Herein, a simple and fast colorimetric strategy has been developed for ADA detection based on the MnO 2 nanosheets-3,3′,5,5′-tetramethylbenzidine (TMB)-glutathione (GSH) as oxidative sensing system (MnO 2 -TMB-GSH). Since the ADA can selectively react with GSH via oxidizing the sulfydryl (-SH) group of GSH to disulfide bond (S-S), which makes GSH unable to reduce MnO 2 nanosheets and restore its oxidase-like activity. The absorbance changes of the TMB solution depended on ADA content. The MnO 2 -TMB-GSH colorimetric platform can detect the ADA with a linear range of 10 μmol L −1 (11.6 ppm) to 400 μmol L −1 (464 ppm), and the limit of detection (LOD) is 3.3 μmol L −1 (3.51 ppm). Some potential interferences in real sample were tested and did not affect the MnO 2 -TMB-GSH colorimetric platform for ADA detection. Furthermore, the sensing platform was applied for detecting ADA in real flour sample with a recovery of 96%–105% (RSD < 5%). This colorimetric method can effectively and rapidly detect ADA additives in flour less than the prescribed standard (45 mg kg −1 ), which shows a great potential for visualization analysis and on-site detection of ADA in flour. Graphical abstract
A simple and fast colorimetric strategy has been developed for azodicarbonamide (ADA) detection based on the MnO 2 nanosheets-3,3′,5,5′-tetramethylbenzidine (TMB)-glutathione (GSH) as oxidative sensing system (MnO 2 -TMB-GSH).
研究领域:
食品安全
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分析化学
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生物传感
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DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2015
·
IF 6.409
Qi-Yong Cai,Jie Li,Jia Ge,Lin Zhang,Ya-Lei Hu,Zhao-Hui Li,Ling-Bo Qu
Glutathione (GSH) serves many cellular functions and plays crucial roles in human pathologies. Simple and sensitive sensors capable of detecting GSH would be useful tools to understand the mechanism of diseases. In this work, a rapid fluorescence “switch-on” assay was developed to detect trace amount of GSH based on carbon dots–MnO 2 nanocomposites , which was fabricated through in situ synthesis of MnO 2 nanosheets in carbon dots colloid solution. Due to the formation of carbon dots–MnO 2 nanocomposites , fluorescence of carbon dots could be quenched efficiently by MnO 2 nanosheeets through fluorescence resonance energy transfer (FRET). However, the presence of GSH would reduce MnO 2 nanosheets to Mn 2+ ions and subsequently release carbon dots, which resulted in sufficient recovery of fluorescent signal. This proposed assay demonstrated highly selectivity toward GSH with a detection limit of 300 nM. Moreover, this method has also shown sensitive responses to GSH in human serum samples, which indicated its great potential to be used in disease diagnosis. As no requirement of any further functionalization of these as-prepared nanomaterials , this sensing system shows remarkable advantages including very fast and simple, cost-effective as well as environmental-friendly, which suggest that this new strategy could serve as an efficient tool for analyzing GSH level in biosamples.
研究领域:
生物化学
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医学诊断
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DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2018
·
IF 2.179
Xiaodan Li,Wendi Zhang,Bo Chen,Gaoxiang Wu,Jiaxiang Cai,Huiqing Wu,Chunhai Jiang
Lithium‐sulfur batteries have stimulated great attention as an advanced power system for scale storage requirements due to the overwhelming energy density . However, the capacity degradation caused by polysulfide shuttle and volume expansion still impedes the practical application. Herein, we designed and fabricated a facile TiO 2 embedded sulfur bulks@MnO 2 nanosheets composite as scalable cathode for long-cyclic lithium-sulfur batteries. The TiO 2 nanoparticles were embedded in sulfur bulks, which played important roles in the coverage of the uniform MnO 2 nanosheets. The embedded TiO 2 sites and external MnO 2 nanosheets brought out the physic trapping and chemical synergistic encapsulation of polysulfides. Such a composite cathode exhibited high reversible capacity of 1289 mAh g −1 at 0.1 C and long-term cycling stability at high rate condition (430 mAh g ‐1 after 500 cycles at 2 C). This work thus sheds new light on a scalable way to improve the electrochemical performance of sulfur cathode.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
IONICS
·
2021
·Vol. 28
·期 1
·139-149
·
IF 2.817
Zhang Xiaole,Li Song,Wang Shenghe,Liu Kun,Zhang Zining,Wen Zhongsheng,Ji Shijun,Sun Juncai
Abstract The main obstacles to the development of manganese-based oxide anode materials for lithium-ion batteries (LIBs) are inherently low conductivity and sluggish electrochemical kinetics. In this work, we propose a strategy of introducing oxygen vacancies (Vö) on the surface of nanostructure at room temperature and atmospheric pressure to improve the electrochemical performance of anode materials. Porous MnO 2 spheroids with 11.2% Vö are fabricated by a ball milling method using commercial electrolytic MnO 2 . The as-synthesized MnO 2 is composed of 20–30 nm nanoparticles. The optimized MnO 2 shows an excellent rate capability of 350 mAh g −1 at 6.4 A g −1 and high specific capacity of 1200 mAh g −1 after 650 cycles under 2 A g −1 . The boosted electrochemical performance is attributed to the porous hierarchical structure and the appropriate Vö concentration involved in the MnO 2 . In addition, the enhanced Li + diffusion coefficient is demonstrated through the kinetics analysis. The approach provides a facile route via tunable Vö concentration for improving the electrochemical performance of manganese-based oxide anode materials for LIBs. Highlight • The porous MnO 2 spheroids with tunable Vö concentrate were synthesized by a ball milling method. • The MnO 2 spheroids are composed of 20-30 nm nanoparticles. • The MnO 2 spheroids exhibit an excellent rate performance and cycling stability. • The ball mill is facile, environmentally friendly, economical for the mass industrial scale.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2020
·Vol. 44
·期 6
·4556-4567
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IF 3.741
Xiaoqi Tan,Shuxia Liu,Qingping Guo,Jie Zhang,Shujun Liang,Maoyong He,Jujie Luo
Summary Amorphous MnO 2 was attached to carbon nanotubes (CNTs) in 60 seconds by solid-state microwave method. As electrodes in supercapacitors, the coactions of the MnO 2 and CNT augmented the actual value of capacitance to 1250 F g −1 , and cycle steadiness held 80% of the starting value after 7000 cycles. The equipped MnO 2 /CNT//AC asymmetric supercapacitor (ASC) manifested preferable energy density with 33.5 Wh kg −1 (at 400 W kg −1 ). Its glorious electrochemical properties of MnO 2 /CNT demonstrated that the microwave method has great potency to realise the composite of electrode materials.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Zhen Lin,Xiaotong Xiang,Kai Chen,Shuijiao Peng,Xiancai Jiang,Linxi Hou
Novel MnO 2 -doped holey carbon materials were obtained by an efficient and facile synthetic method using chitosan, potassium hydroxide and potassium permanganate as the raw materials. The carbon framework with high specific surface area was derived from chitosan by carbonization and activation approach, afterwards, MnO 2 nanorods were grown on the surface of porous carbon by one-step agitation method and the MnO 2 -doped holey carbon material was obtained. The scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy , X-ray diffraction, N 2 adsorption-desorption measurements, Raman spectroscopy and X-ray photoelectron spectroscopy were employed to analyze the physicochemical characteristics of the MnO 2 -doped holey carbon materials. The electrochemical performance of these materials displayed well through relative tests including cyclic voltammetry , galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements in 6.0 M KOH solution. Especially, this as-obtained electrode material with the optimum ratio presented a high gravimetric capacitance (460F g −1 at 0.2 A g −1 ) and exceptional capacitance reservation (91.67% at 10 A g −1 over 10,000 cycles) in the three-electrode system with 6.0 M KOH solution as the electrolyte.
研究领域:
材料科学
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电化学
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DOI
PubMed
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2022
·
IF 7.926
Mengyue Zhang,Jun Dong,Minglu Sun,Chen Sun,Yujiao Han,Yanyang Mo,Weihong Zhang
The remediation of trichloroethylene contaminated groundwater by permanganate-based in situ chemical oxidation is limited by MnO 2 formation. The application of phase transfer catalyst (PTC) is a promising alternative to enhance remediation efficiency, and the alleviation of MnO 2 generation is one of crucial capacities of PTC to promote oxidation. This work has emphatically elucidated the mechanism of MnO 2 alleviation by PTC, as well as the effectiveness which was researched by conducting batch and sand column experiments. The results indicated that the contents of MnO 2 suspended in aqueous phase and total manganese in the media were respectively decreased by 29.5% and 26.1% attributed to PTC addition. Although PTC could not be used as a chelator for Mn(Ⅲ) stabilization, the generation of dissolved Mn(Ⅱ) and Mn(Ⅲ) was promoted by PTC for less MnO 2 generation. Further studies illustrated that redox reactions would occur between dissolved Mn(Ⅱ)/Mn(Ⅲ) and TCE, which benefited TCE degradation. Moreover, Smaller particle size and improved colloidal stabilization of formed MnO 2 were achieved by PTC to minimize MnO 2 precipitation. Overall, effective alleviation of the MnO 2 generation and precipitation by PTC is collectively contributed from the promotion of dissolved Mn(Ⅱ) and Mn(Ⅲ) and the stabilization of MnO 2 formed in situ.
研究领域:
环境科学
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化学工程
·
水处理
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高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Bohong Li,Meiyu Wang,Jingjin Zhao
Ascorbic acid (AA) which can be supplemented by exogenous sources such as food and beverage, plays an important role in human health. Abnormal level of AA in human body usually leads to various diseases. A facile MnO 2 nanosheet-assisted ratiometric fluorescent sensor for AA was constructed in this work. MnO 2 nanosheet (MnO 2 NS) could not only greatly quench the fluorescence of Pyronin Y (PY) by inner filter effect (IFE) but also oxidize non-fluorescent thiamine (vitamin B 1 , VB 1 ) to blue fluorescent thiochrome (oxVB 1 ) by taking advantage of the oxidase-mimicking activity simultaneously. However, MnO 2 NS could be reduced to Mn 2+ in the presence of AA, inhibiting the IFE and oxidase-mimicking activity. According to this principle, the fluorescence intensity of oxVB 1 decreasing at 440 nm and the fluorescence of PY recovering at 560 nm. Under optimal conditions, the MnO 2 NS-PY-VB 1 system showed a wide linear range towards AA in the range of 0.25–110 µM with a low detection limit reaching 0.1 µM. Furthermore, it was also applied for sensitive detection of AA in orange juice and human serum.
研究领域:
分析化学
·
生物化学
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传感器与执行器
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材料科学
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DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Yang-feng Cui,Zhen-bang Zhuang,Zi-long Xie,Ren-fei Cao,Qi Hao,Ning Zhang,Wan-qiang Liu,Yun-hai Zhu,Gang Huang
Alkaline Zn–MnO2 batteries feature high security, low cost, and environmental friendliness while suffering from severe electrochemical irreversibility for both the Zn anode and MnO2 cathode. Although neutral electrolytes are supposed to improve the reversibility of the Zn anode, the MnO2 cathode indeed experiences a capacity degradation caused by the Jahn–Teller effect of the Mn3+ ion, thus shortening the lifespan of the neutral Zn–MnO2 batteries. Theoretically, the MnO2 cathode undergoes a highly reversible two-electron redox reaction of the MnO2/Mn2+ couple in strongly acidic electrolytes. However, acidic electrolytes would inevitably accelerate the corrosion of the Zn anode, making long-lived acidic Zn–MnO2 batteries impossible. Herein, to overcome the challenges faced by Zn–MnO2 batteries, we propose a hybrid Zn–MnO2 battery (HZMB) by coupling the neutral Zn anode with the acidic MnO2 cathode, wherein the neutral anode and acidic cathode are separated by a proton-shuttle-shielding and hydrophobic-ion-conducting membrane. Benefiting from the optimized reaction conditions for both the MnO2 cathode and Zn anode as well as the well-designed membrane, the HZMB exhibits a high working voltage of 2.05 V and a long lifespan of 2275 h (2000 cycles), breaking through the limitations of Zn–MnO2 batteries in terms of voltage and cycle life.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2021
·
IF 3.512
Hongzhi Lu,Shoufang Xu
Manganese dioxide (MnO2) nanosheet-based fluorescence sensors often use oxidase-like activity or wide absorption spectrum for detection of antioxidants. In those strategies, MnO2 nanosheets were reduced to Mn2+ by antioxidants. However, few strategies emphasize the role of Mn2+ obtained from MnO2 reduction in the design of the fluorescence sensor. Herein, we expanded the application of a MnO2 nanosheet-based fluorescence sensor by involving Mn2+ in the detection process using ascorbic acid (AA) as a model target. In this strategy, carbon dots (CDs), MnO2 nanosheets, and tetraphenylporphyrin tetrasulfonic acid (TPPS) comprise a ternary system for ratiometric fluorescence detection of AA. Initially, CDs were quenched by MnO2 nanosheets based on the inner filter effect, while TPPS maintained its fluorescence intensity. After the addition of AA, MnO2 nanosheets were reduced to Mn2+ so that the fluorescence intensity of CDs was recovered and TTPS was quenched by coordination with Mn2+. Overall, AA triggered an emission intensity increase at 440 nm for CDs and a decrease at 640 nm for TPPS. The ratio intensity of CDs to TPPS (F440/F640) showed a good linear relationship from 0.5 to 40 μM, with a low detection limit of 0.13 μM for AA detection. By means of the alkaline phosphatase (ALP)-triggered generation of AA, this strategy can be applied for the detection of ALP in the range of 0.1–100 mU/mL, with a detection limit of 0.04 mU/mL. Furthermore, this sensor was applied to detect AA and ALP in real, complex samples with ideal recovery. This novel platform extended the application of MnO2 nanosheet-based fluorescence sensors.
研究领域:
分析化学
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纳米技术
·
生物传感器
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）