Materials
·
2021
·Vol. 14
·期 16
·4402
·
IF 3.623
Qingqing Cao,Siqi Lu,Wenjun Yin,Yan Kang,Naihao Yang,Yudong Hou,Zizhang Guo
High-ring polycyclic aromatic hydrocarbons (PAHs, Benzo[b]fluorathene (BbFA), etc.) are difficult to biodegrade in the water environment. To address this issue, an innovative method for the preparation of MnO2nanoflower/graphene oxide composite (MnO2NF/GO) was proposed for adsorption removal of BbFA. The physicochemical properties of MnO2NF/GO were characterized by SEM, TEM, XRD, and N2adsorption/desorption and XPS techniques. Results show that the MnO2NF/GO had well-developed specific surface area and functional groups. Batch adsorption experiment results showed that adsorption capacity for BbFA was 74.07 mg/g. The pseudo-second-order kinetic model and Freundlich isotherm model are fitted well to the adsorption data. These show electron-donor-acceptor interaction; especially π-π interaction and π complexation played vital roles in BbFA removal onto MnO2NF/GO. The study highlights the promising potential adsorbent for removal of PAHs.Keywords:MnO2nanoflower;graphene oxide;PAHs;adsorption
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 8
·080524
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IF 4.316
Qiang Zhou,Gongbin Tang,Xiuhang Chen,Fenghua Su
Solid-state flexible supercapacitors are considered significant prospective energy storage devices, and carbon nanotube (CNT) yarn is an ideal electrode material for constructing linear flexible supercapacitors because of its high electrical conductivity and flexibility. However, the relatively low specific capacitance and energy density of a supercapacitor made of pure CNT yarn limits its application. Here, we prepared a CNT/MnO2-BP composite yarn via a facile one-step liquid deposition method by the innovative introduction of few-layer black phosphorous (BP) nanosheets. The redox reaction between the BP and the potassium permanganate forms MnO2 and an electrolyte of phosphorus acids (HxPOy). The two-ply yarn supercapacitor composed of the CNT/MnO2-BP composite yarn shows excellent electrochemical properties with a volumetric capacitance of 441.79 F cm−3 at the scanning rate of 0.01 V s−1 and an energy density of 9.82 mWh cm−3 at a power density of 441.79 mW cm−3. Herein, this work provides a way to improve the electrochemical performance of CNT yarn-based supercapacitors that can act as flexible energy storage devices for wearable electronics.
研究领域:
材料科学
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能源存储技术
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Ying Cao,Jiaojiao Liu,Lina Zou,Baoxian Ye,Gaiping Li
In this work, a facile ratiometric fluorescence sensor for GSH measurement was designed based on MnO 2 nanosheet (NS), carbon dots (CDs), as well as a simple substrate o-phenylenediamine (OPD). Herein, MnO 2 NS played triple essential roles in the sensing system. First, it could be reduced by GSH through a special reaction, and therefore served as GSH recognizer. Second, it played as a fluorescence nanoquencher to strongly quench the fluorescence of CDs. Third, it could directly oxidize OPD to yield a luminescent product 2, 3-diaminophenazine (DAP) via the intrinsic oxidase-like activity. It revealed that MnO 2 NS could be reduced to Mn 2+ in the presence of GSH. Thus its oxidase-like activity and fluorescence quenching abilities were inhibited, which then restricted the generation of DAP and recovered the fluorescence of CDs. Based on this phenomenon, a novel ratiometric fluorescence sensor for GSH determination was fabricated by measuring the ratio of fluorescent intensity of DAP to that of CDs. Besides, the constructed ratiometric fluorescent sensor, which could be facilely operated with single-wavelength excitation, exhibited high sensitivity and selectivity with a wider linear range and a lower detection limit.
研究领域:
分析化学
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生物医学工程
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Jia-Jia Xu,Ya-Fei Cheng,Lian-Zeng-Ji Xu,Xiao-Ling Zhu,Wei-Qin Zhu,Ren-Cun Jin
The response of anaerobic ammonium oxidation (anammox) process and granular sludge in the upflow anaerobic sludge blanket reactor was analyzed under long-term exposure to MnO 2 nanoparticles (NPs) (1–200 mg L −1 ). The addition of 200 mg L −1 MnO 2 NPs had a significantly positive effect on nitrogen removal and this system exhibited excellent performance, with a total nitrogen removal efficiency of 93.1%. Moreover, the specific anammox activity enhanced with increasing concentrations of MnO 2 NPs up to the maximum value of 657.3 ± 9.3 mg TN g −1 VSS d −1 under MnO 2 NPs concentration of 200 mg L −1 . This value was approximately 1.6-fold higher than that of the reactor in the absence of MnO 2 NPs. The extracellular polymeric substances and settling velocity were both increased with MnO 2 NPs addition. Meanwhile, the high-throughput sequencing results revealed that MnO 2 NPs increased the relative abundance of dominant bacteria ( Candidatus Kuenenia ) from 17.3% at the absence of MnO 2 NPs to 23.9% at 200 mg L −1 MnO 2 NPs, which resulted in a higher efficiency of biological nitrogen removal on the anammox system. These results indicated that MnO 2 NPs enhanced nitrogen removal performance of anammox process.
研究领域:
环境工程
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微生物学
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DOI
PubMed
高影响因子
Materials
·
2019
·Vol. 12
·期 15
·2379
·
IF 2.972
Xin-Sheng Li,Man-Man Xu,Yang Yang,Quan-Bo Huang,Xiao-Ying Wang,Jun-Li Ren,Xiao-Hui Wang
Two corncob-derived carbon electrode materials mainly composed of micropores (activated carbon, AC) and mesopores/macropores (corncob carbon, CC) were prepared and studied after the anodic electrodeposition of MnO2. The capacity of the MnO2/activated carbon composite (MnO2@AC) electrode did not noticeably increase after MnO2electrodeposition, while that of the MnO2/corncob carbon composite (MnO2@CC) electrode increased up to 9 times reaching 4475 mF cm−2. An asymmetric all-solid-state supercapacitor (ASC) was fabricated using AC as the anode, MnO2@CC as the cathode, and polyvinyl alcohol (PVA)/LiCl gel as the electrolyte. An ultrahigh specific capacitance of 3455.6 mF cm−2at 1 mA cm−2, a maximum energy density of 1.56 mW h cm−2, and a long lifetime of 10,000 cycles can be achieved. This work provides insights in understanding the function of MnO2in biomass-derived electrode materials, and a green path to prepare an ASC from waste biomass with excellent electrochemical performance.Keywords:natural biomass;porous carbon;architecture;MnO2;supercapacitor
研究领域:
材料科学
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能源技术
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DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Lijun Zhu,Hao Cheng,Jianfeng Ma,Yong Kong,Yong Qin,Sridhar Komarneni
Decolorization of methyl orange (MO) by MnO 2 was investigated with and without small molecules of organic acids such as formic acid. It was found that the decolorization could be significantly improved by MnO 2 with the assistance of organic acids. The effect of various conditions was investigated on MO decolorization by using different crystal types of MnO 2 and changing the types of organic acids. One of the optimum treatment conditions was δ-MnO 2 /formic acid system, which led to the removal efficiency of 90.6% at 30 min. The pseudo-second-order kinetic rate constant of δ-MnO 2 /formic acid was 0.1626. A reasonable decolorization mechanism involving Mn(III) species was proposed and the mechanism was validated by simple detection of ionic species such as, Mn(II) and Mn(III) during the reaction. The δ-MnO 2 /formic acid process designed here may lead to a new advanced oxidation technology based on the in-situ generation of active Mn(III) species and their ability for oxidation.
研究领域:
环境科学
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化学
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DOI
高影响因子
TALANTA
·
2019
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IF 4.916
Yanlin Du,Hui Liu,Jiaming Liang,Dongye Zheng,Jiong Li,Shubing Lan,Ming Wu,Aixian Zheng,Xiaolong Liu
Herein, a bovine serum albumin-stabilized gold clusters-MnO 2 nanocomposite (BSA@AuNCs–MnO 2 ) was constructed. Manganese dioxide (MnO 2 ) was generated in situ on the gold clusters (BSA@AuNCs) based on the redox reaction between bovine serum albumin (BSA) and potassium permanganate (KMnO 4 ). The fluorescence of BSA@AuNCs can be quenched by the in-situ grown MnO 2 , which has strong light absorption ability. It is worth noting that the quenched fluorescence of the BSA@AuNCs can be restored in the presence of glutathione (GSH), and MnO 2 was reduced to Mn 2+ in return. Encouragingly, 1 μM GSH can cause a detectable fluorescence change. This sensitivity is comparable to other nanomaterials based fluorescent probes . Furthermore, this nanocomposite has obvious superiorities, such as good uniformity, simple preparation and mild reaction. The nanocomposite also has good stability and specificity, which can be further used for visualizing of intracellular GSH.
研究领域:
生物化学
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纳米医学
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分析化学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Wenhua Tong,Jiepeng Wang,Xinhang Du,Xuqian Wang,Yabo Wang,Yongkui Zhang
The treatment of tributyl phosphate (TBP) extractant waste from specific industry, eg., nuclear industry, is a great challenge due to its stability and high environmental risk of phosphorus-containing species releasing. Inspired by chemical looping combustion (CLC) technology , a MnO 2 -assisted thermal oxidation strategy is proposed for TBP degradation and simultaneously P immobilization. Under recommended reaction conditions of 220 °C, 10 g MnO 2 mL −1 TBP and 3 h reaction duration, a high P immobilization efficiency of 93.99% is achieved. Material characterization results indicate that P is mainly immobilized in the form of Mn 2 P 2 O 7 , which greatly reduces the environmental risk of P-containing species. TBP degradation intermediates are further identified by thermogravimetric-gas chromatography-mass spectrometry (TG-GC-MS), liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS), which facilitates understanding of reaction mechanisms as well as proposing possible pathways of TBP degradation. It is suggested that MnO 2 provides essential oxygen as oxygen carrier for flameless combustion. Meantime, MnO 2 reduction leads to the generation of Mn(III) species. The existence of oxygen vacancy in MnO 2 also facilitates •O 2 - radical generation. Under flameless combustion and attacks of Mn(III) and •O 2 - , TBP is firstly degraded into intermediates and finally mineralized into CO 2 and H 2 O, while P is mainly immobilized as pyrophosphate.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
Coatings
·
2025
·Vol. 15
·期 3
·298
·
IF 2.8
Xiangchen Zhang,Wenyuan Bao,Hongwei Cai,Ruixi Chen,Kai Fu,Wen Luo
The growing demand for efficient energy storage solutions has highlighted the potential of aqueous sodium-ion (Na+) batteries, known for their cost-effectiveness and environmental benefits. Despite their promise, challenges such as low specific capacities resulting from proton (H⁺) intercalation issues have limited their effectiveness. This study introduces a novel alkaline electrolyte environment using tetrabutylammonium hydroxide (TBAH) combined with chloride ions (Cl−) to improve the Na+storage performance of manganese oxide (MnO2) cathodes. The optimized electrolyte achieved a remarkable reversible capacity of 101 mAh g−1forγ-MnO2at a current density of 0.1 A g−1, surpassing conventional aqueous solutions. The synergistic effect of TBAH and Cl−not only suppresses H+intercalation, but also prevents the formation of manganese hydroxide passivation layers during cycling. These advancements contribute to a better understanding of electrolyte design for high-performance Na+storage electrodes, marking a significant step forward in aqueous sodium-ion battery technology.
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
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 24
·9178-9184
·
IF 0
Xiaomiao Feng,Ningna Chen,Yu Zhang,Zhenzhen Yan,Xingfen Liu,Yanwen Ma,Qingming Shen,Lianhui Wang,Wei Huang
Graphene–MnO2 nanocomposites with different morphologies were obtained by a facile self-assembly method. The formation mechanism of graphene–MnO2 composites with different shapes of MnO2 is discussed in detail. Nanostructured MnO2 with different morphologies was distributed on the surface of graphene uniformly. The prepared graphene–MnO2 composites could be used as electrode materials for supercapacitors. The graphene–MnO2 (flowerlike nanospheres) composite (405 F g−1) exhibited better capacitive performance than that of the graphene–MnO2 (nanowires) composite (318 F g−1) at a current density of 1.0 A g−1. The synergistic effect of graphene and MnO2 endowed the composite with high electrochemical capacitance. Moreover, the graphene–MnO2 (flowerlike nanospheres) composite showed a fast charge–discharge process and high cyclic stability.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Zhi Song,Yu-Long Ma,Cong-Er Li
The object of this study was to remove the tetracycline (TC) residue in pharmaceutical wastewater after flocculation treatment. MnO 2 /graphene nanocomposite was synthesized by an in situ hydrothermal method and its TC removal rate was up to 99.4%. This nanocomposite had excellent water solubility. More importantly, the introduction of MnO 2 nanorods allowed the avoidance of excessive stacking of treated graphene sheets during the adsorption process, which made the TC molecules to have more opportunities to make contact with the adsorbents. In order to eliminate the interference factors, the adsorption isotherm, kinetics, thermodynamics and mechanism were all studied in TC aqueous solution. The influence of solution pH, contact time, MnO 2 loading amount, temperature and solution concentration on the adsorption process were also assessed. The main adsorption mechanism contributed to the complexation of Mn(IV) and π-π interactions of the benzene ring structure on treated graphene sheets with TC molecules.
研究领域:
环境科学
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材料科学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Lian-Kui Wu,Jie Xia,Guang-Ya Hou,Hua-Zhen Cao,Yi-Ping Tang,Guo-Qu Zheng
We report a novel silica co-electrodeposition route to prepare nanostructured MnO 2 films. Firstly, MnO 2 -SiO 2 composite film was fabricated on a stainless steel substrate by potentiodynamical deposition, i.e. cyclic deposition, and then the SiO 2 template was removed by simple immersion in concentrated alkaline solution, leading to the formation of a porous MnO 2 (po-MnO 2 ) matrix. The structure and morphology of the obtained films were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties of the po-MnO 2 film were evaluated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS). Results showed that this porous MnO 2 derived from the MnO 2 -SiO 2 composite film exhibits good electrochemical performance for potential use as a supercapacitor material.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）