ACS Applied Energy Materials
·
2022
·
IF 6.959
Hui Peng,Faqiang Wang,Danyang Wang,Shuzhen Cui,Wenbo Hou,Guofu Ma
Aqueous Zn–MnO2 batteries have received much attention due to their low cost, safety, reliability, and large storage capacity. However, the sluggish ion/electron transport kinetics of bulk MnO2 inevitably decreases the rate capability and cycle stability of Zn–MnO2 batteries. Herein, hierarchical MnO2 nanosheet arrays self-anchored and grown in polyaniline-derived carbon nanotubes (PCNT@MnO2, denoted as PCMO) with enhanced stability are prepared by employing PCNT as both a substrate and a sacrificial reductant. The hollow PCNT conductive skeleton feature and robust integrated MnO2 nanosheet arrays in PCMO are not only favorable for enhancing electronic conductivity and accelerating electronic migration but also provide effective nucleation sites for the growth of MnO2 nanosheets and unimpeded ion channels, resulting in high specific capacity, rapid ion-diffusion kinetics, and long-term cycle stability. Specifically, the optimized PCMO material (PCMO-2) can deliver 264 mAh g–1 at 0.2 A g–1 after 120 cycles without obvious capacity decay, superior to the bare MnO2 material. Moreover, the as-fabricated PCMO//Zn battery can exhibit a high energy density of 320.2 Wh kg–1 at a power density of 120 W kg–1. The rational design of low-cost and integrated core–shell architecture with robust contact between MnO2 nanosheet arrays and a hollow conductive skeleton is expected to achieve cost-effective and high-performance Zn–MnO2 batteries.
研究领域:
材料科学
·
电化学
·
能源存储与转换
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产品关联
DOI
高影响因子
NANO
·
2025
·
IF 1.1
Xiaofeng Yang,Dongdong Li,Longgui Peng,Jiushuang Huang
Manganese dioxide (MnO 2 ), known for its high theoretical specific capacitance, is considered one of the most promising electrode materials for supercapacitors. However, its poor intrinsic conductivity and structural degradation during cycling severely limit its practical application. To address these challenges, an interwoven MnO 2 nanofiber network-based attapulgite (ATP)/MnO 2 composite was constructed by in-situ growth of MnO 2 nanofibers on natural ATP clay scaffolds via a one-step hydrothermal method. The microstructures and morphologies of pure ATP, pure MnO 2 , and the ATP/MnO 2 composite were systematically characterized and compared. Furthermore, the electrochemical performances of pure MnO 2 and the ATP/MnO 2 composite were evaluated. Results indicate that the ATP/MnO 2 composite possesses a more favorable specific surface area and pore structure than pure ATP or MnO 2 , with an approximate 40% increase in specific surface area. Electrochemical measurements demonstrated that the ATP/MnO 2 composite delivered a specific capacitance of 218.8 F g -1 at a current density of 0.5 A g -1 , approximately 50% higher than that of pure MnO 2 . Moreover, the composite exhibited outstanding cycling stability, retaining 89.9% of its initial capacitance after 5000 charge-discharge cycles at 3 A g -1 . This study demonstrates the role of natural ATP in synergistically optimizing the specific surface area and active sites of MnO 2 -based materials. The proposed strategy offers a feasible route for designing high-performance, low-cost, and sustainable MnO 2 -based electrodes, while also providing new insights into the development of long-lasting energy storage materials.
研究领域:
材料科学
·
储能
·
纳米技术
·
电化学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shihao Su,Guojun Lv,Jialing Shen,Fuxin Wang,Lachgar Oussama,Yan Chen,Shengnan Xu
In the tandem synthesis of 1,2-cyclohexanediol, solvents such as acetonitrile are often added to eliminate the immiscibility of cyclohexene with water and accordingly strengthen the interphase mass transfer; however, the usage of solvents artificially increases the solvent separation procedure, enhancing the energy consumption and decreasing the economic benefits of the reaction process. Hence, the development of the solvent-free Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol is extremely appealing. In this study, β-MnO2 and Mn2O3 were prepared by calcining γ-MnO2 synthesized with the hydrothermal synthesis method and concurrently served as a colloidal emulsifier and a heterogeneous catalyst in the Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol at room temperature in the presence of the oxidant molecular oxygen and the co-oxidant isobutyraldehyde. The prepared β450-MnO2 sample revealed the best tandem catalysis performance, achieving a cyclohexene conversion of 99.4% and a 1,2-cyclohexanediol selectivity of 83.6% within 4 h of reaction, which can be ascribed to the highest Mn4+/Mn3+ ratio and the greatest concentration of oxygen vacancies as well as the most stable Pickering emulsion. At the same time, density functional theory (DFT) studies further confirmed that isobutyraldehyde and molecular oxygen could be more easily adsorbed and activated by β450-MnO2 in comparison with the other catalyst samples, benefiting its eminent catalytic epoxidation performance. In addition, a possible reaction mechanism for the β450-MnO2 catalyst catalyzing cyclohexene into 1,2-cyclohexanediol in the Pickering interfacial tandem catalytic reaction system was put forward and validated through quenching experiments as well as in situ infrared characterization. The synthesized β450-MnO2 catalyst exhibited reusability for greater than 5 cycles, and meanwhile, the Pickering interfacial tandem catalytic reaction system can be expanded to a spread of linear and cyclic alkene substrates, highlighting the superiority of the β450-MnO2 catalyst. These findings verify that the synthesized β450-MnO2 catalyst is capable of being utilized as an efficient and stable catalyst for the Pickering interfacial catalytic conversion of alkenes into 1,2-diols at room temperature.
研究领域:
化学工程
·
催化科学
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产品关联
DOI
高影响因子
Talanta Open
·
2024
·
IF 4.1
Chen-Xi Zhao,Xiao-Xia Li,Yang Shu
Abnormal alkaline phosphatase levels have been associated with several diseases, including tumor growth, diabetes, liver dysfunction and so on. Generally, the occurrence and prognosis of these diseases can be reflected by the serum alkaline phosphatase level. In this work, Eu/DBM@SiO 2 @SiO 2 is prepared to protect the internal Eu complex from the external environment by wrapping Eu/DBM inside the silica shell. Then, Eu/DBM@SiO 2 @SiO 2 /MnO 2 , a sensor consists of Eu/DBM@SiO 2 @SiO 2 and MnO 2 , is prepared and applied for alkaline phosphatase detection. MnO 2 is used as the response part of alkaline phosphatase, which can be degraded to Mn 2+ by ascorbic acid. Ascorbic acid is the hydrolysate of alkaline phosphatase. In the process of this reaction, UV–vis absorption of Eu/DBM@SiO 2 @SiO 2 /MnO 2 is reduced and fluorescence is turned on. Alkaline phosphatase concentration is linearly correlated with the logarithmic value of fluorescence enhancement in the range of 10.0–100.0 U/L with linear equation of Lg(F/F 0 )=0.008C-0.030 (R 2 =0.99). For fluorescence method, the LOQ is 10.0 U/L and the LOD is 4.4 U/L. For colorimetric method, the concentration of alkaline phosphatase is linearly correlated with the decrease of absorption intensity in the range of 20.0–90.0 U/L with the linear equation of A/A 0 =-0.012C+1.148 (R 2 =0.99). The LOQ is 20.0 U/L and the LOD is 7.2 U/L. The detection system has good selectivity and can detect alkaline phosphatase in human serum samples, the accuracy of the detection system is verified by the experiment of spike-in experiment. The RSD of alkaline phosphatase concentration in serum samples is in the range of 1.4–8.4 %. This method has potential application in the detection of ALP activity in biological samples.
研究领域:
生物化学
·
医学诊断
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Junwen Ding,Jinlong Wang,Xinsheng Luo,Daliang Xu,Yatao Liu,Peijie Li,Shirong Li,Rui Wu,Xinlei Gao,Heng Liang
Membrane-based technology has been confirmed as an effective way to treat emulsified oily wastewater, however, membrane fouling is still one of practical challenges in long-term operation. Herein, a novel passive-active combined strategy was proposed to control membrane fouling in continuous oily wastewater purification, where the δ-MnO 2 decoration layer helped to reduce the total fouling ratio (passive strategy for fouling mitigation) and the catalytic cleaning effectively removed the irreversible oil fouling (active strategy for fouling removal). The functional membrane was prepared via in-situ modification, referred to as δ-MnO 2 @TA-PES. The morphology, crystalline phase, chemical structure and surface properties of the membranes were systematically characterized. Compared with PES, the δ-MnO 2 @TA-PES possessed superhydrophilicity, enhanced electronegativity and narrowed pore size. The δ-MnO 2 @TA-PES achieved high water permeation flux of 723.9 L· m − 2 · h − 1 ·bar −1 , excellent oil rejection with separation efficiency above 98.5% for various emulsions, and durable anti-oil-fouling performance with FRR b of 98.0%. Notably, the oil cake layer fouling on δ-MnO 2 @TA-PES was greatly alleviated owing to its enhanced surface properties. In addition, δ-MnO 2 @TA-PES showed high cleaning efficiency in the peroxymonosulfate (PMS) cleaning process, where the radical and nonradical pathways occurred simultaneously. And the active substances generated in the nonradical process (especially 1 O 2 ) were considered as the main contributor to the reduction of irreversible fouling. Overall, the novel strategy of fouling control ensured the efficient operation of ultrafiltration membranes for the continuous oily wastewater purification.
研究领域:
环境工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 41
·29061-29069
·
IF 3.9
Xixi Wu,Huazhen Liang,Chaoming Li,Duanyang Zhou,Rui Liu
The specific tumor microenvironment is a conducive breeding ground for malignant tumors, favoring their survival, rapid proliferation, and metastasis, which is also an inevitable obstacle to tumor treatment, particularly for catalytic therapy. To address this issue, a hyperthermia-enhanced nanocatalyst (AuP@MnO2) consisting of an asymmetric Au@polypyrrole core and a MnO2 shell is constructed for synergistic cancer Fenton/photothermal therapy. In an ultra-short reaction time (15 min), the innovative introduction of a new oxidizer, tetrachloroauric acid trihydrate, not only successfully initiates the oxidative polymerization of pyrrole monomer while reducing itself to cubic Au, but also accelerates the polymerization process by supplying protic acid. After MnO2 coating, AuP@MnO2 catalyzes the conversion of antioxidant GSH and excess H2O2 into GSSG and ˙OH through Mn2+/Mn4+ ion couples, leading to oxidative damage of tumor cells. More importantly, after 1064 nm laser irradiation, more extreme oxidative imbalance and cell death are demonstrated in this work under the combined effect of photothermal and catalytic therapy, with insignificant toxicity to normal cells. This work develops an efficient one-step synthesis method of asymmetric Au@polypyrrole and provides constructive insight into its oxidative stress-based antitumor treatment.
研究领域:
纳米医学
·
肿瘤治疗
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催化医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Yan Li,Libing Zhang,Zhen Zhang,Yu Liu,Jing Chen,Jia Liu,Peiyao Du,Huixia Guo,Xiaoquan Lu
Manganese dioxide nanosheets combined with cysteine-assisted emitting manganese dioxide nanospheres (Cys-MnO2 nanospheres) is fabricated for the first time as an “off–on” fluorescence detection platform for glutathione (GSH). In this sensing system, Cys-MnO2 nanospheres served as energy donors, while MnO2 nanosheets were used as both energy acceptors and recognition units. MnO2 nanosheets can effectively quench the fluorescence of Cys-MnO2 nanospheres through the fluorescence resonance energy transfer (FRET). The addition of GSH could reduce MnO2 nanosheets into Mn2+, disrupting the FRET process and restoring the fluorescence of Cys-MnO2 nanospheres. Under the optimum conditions, the “switch-on” platform we established has a wide response to GSH with a range of 5–50 μM and 150–800 μM, as well as a superior specificity. Importantly, all components of the sensor are nontoxic, biocompatible, easily prepared, and have a high utilization of raw materials. Moreover, the sensing system achieved satisfactory results in human serum, showing a tremendous potential in the field of biomedicine.
研究领域:
生物化学
·
分析化学
·
医学诊断
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Yuqing Li,Can Liu,Xiaocong Tang,Bohao Liu,Wei Zhao,Yong Zhang
Metal nanoparticle surface modification is a simple and efficient method to realize highly sensitive detection for chemiresistive gas sensors. Although a few theoretical explanations for the complicated matching relationship in the sensing system constructed from the modified metal, semiconductor material, and target gas have been proposed, there are no corresponding specific evaluation parameters based on the metal sensitization mechanism, which are crucial for the guidance of high-performance sensing materials design. Herein, taking MnO2-based chemiresistive gas sensors as examples, the improvement effect of the metal nanoparticles modification on the gas-sensing properties of MnO2-based chemiresistive sensors toward HCHO and NH3 is investigated. Combined with the first-principle calculations based on density functional theory (DFT), a novel resonant coupling model based on the impurity energy levels, originating from charge transfer between target gas and metal, is first proposed to reveal the sensitization mechanism that the coupling strength between metal and target gas determines the carrier concentration of MOS. Coupling strength is closely positive correlated with the response, which provides an effective parameter to semiquantitatively describe the sensitization effect of metal nanoparticles on target gas. Our work establishes a model that clarifies the matching correlation in the sensing system and excavates new road to further comprehend the metal sensitization mechanism, which will provide an effective theoretical guide for the design of high-performance gas-sensing materials.
研究领域:
材料科学
·
化学传感器
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jiesong Tan,Yiqing Zeng,Jiahao Chen,Yutang Kang,Jiangxiao Qiao,Feng Zhang,Feng Han,Zhaoxiang Zhong,Weihong Xing
Oily particulate matter (PM) filtration faces the problems of high pressure drop and difficult regeneration. Herein, vertical arrays of MnO 2 nanosheets was assembled on Zr doped TiO 2 (Zr-TiO 2 ) nanofibers to construct a core–shell structure MnO 2 @Zr-TiO 2 (CSMT-x) catalytic membranes for highly efficient oily PM filtration and decomposition. The confining effect of the ultrathin MnO 2 nanosheets enhances PM capture efficiency, and the increase of effective contact area between MnO 2 and oily PM accelerate the decomposition of oily PM. The optimized CSMT-3 catalytic membrane exhibited high gas permeability and redox capacity, outperforming the Zr-TiO 2 (Bare T) membrane with over 99.97 % PM filtration efficiency and a low pressure drop at the temperatures of 25–425 °C. The catalytic decomposition of PM prevented the accumulation of particles on the membrane surface, which inhibited the formation of cake layer. Therefore, the CSMT-3 membrane exhibited a slight increase in pressure drop (less than 120 Pa) even after 120 h long-term filtration. This work may contribute to the development of advanced multifunctional membranes for purification of oily PM.
研究领域:
材料科学
·
环境工程
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产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2022
·
IF 3.51
Haoxuan Wei,Jujiao Zhao,Md. Hasibur Rahaman,Quanfeng Wang,Jun Zhai
In this study, the catalytic activity of soluble Mn(III) ions, soluble Mn(III)-pyrophosphate (PP), and solid Mn(III) (α-MnO 2 ) towards peroxymonosulfate (PMS) activation was investigated through carbamazepine (CBZ) degradation. The degradation efficiency of CBZ was negligible when soluble Mn(III) ions or Mn(III)-PP were used as catalysts, while 99.7% of CBZ was degraded in the α-MnO 2 /PMS system with no soluble Mn(III) ions detected. The degradation efficiency of CBZ reduced by 18% with the solid Mn(III) content decreasing. Hence, the solid Mn(III) made the major contribution to PMS activation. This study supported a better understanding of the role of Mn(III) in PMS activation.
研究领域:
环境化学
·
催化
·
水处理
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Yan Li,Defa Huang,Wenjiang Shen
Supercapacitors based on MnO 2 /CB/C nanocomposites films are prepared by direct electrophoretic deposition (EPD) process on nickel plates in an aqueous solution containing of MnO 2 nanoparticles , carbon black (CB) and sodium alginate (SA), followed by carbonization of SA to carbon layer . The nanocomposites of MnO 2 /CB/C films are prepared from different electrolytic solutions with mass ratios of MnO 2 nanoparticles, CB and SA from 8: 1: 1 to 6: 2: 2. Same mass ratios of nanocomposites are prepared by traditional Doctoral Blade (DB) process for morphologies and performances comparisons, in which mixtures of MnO 2 nanoparticles, carbon black with polyvinylidene fluoride (PVDF) are used. From scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) images, the MnO 2 /CB/C shows a uniform aggregation of MnO 2 and carbon nanoparticles covered with carbon layers. In the case of the MnO 2 /CB/PVDF from DB process, the MnO 2 nanoparticles are separately clustered, and the clusters are adhered to CB together with PVDF. More uniform film and better contact of MnO 2 with CB by carbon layer can be obtained from EPD/Carbonization process. The electrochemical performances of MnO 2 /CB/C and MnO 2 /CB/PVDF nanocomposites in different mass ratios are compared by areal specific capacitances (C a ), charge transfer resistance of films and retention of capacitance after 1500 cycles of charge/discharge to test stability respectively. The nanocomposites of MnO 2 /CB/C show better areal specific capacitances and smaller charge transfer resistances at each ratio. The carbon layer coating on surface of MnO 2 nanoparticles can effectively delay the capacitance loss, which leads to 98% of capacitance after charge/discharge cycles, much better than retention of those from DB process (50%). The EPD/Carbonization is an easy way to make carbon layer on pseudo capacitive materials from sodium alginates , and the carbon layer can effectively improve the charge/discharge stability of supercapacitors.
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DOI
高影响因子
FIBERS AND POLYMERS
·
2025
·
IF 2.3
Zhang Dewei,Sun Hui,Yu Bin,Xie Youxiu,Li Fengchun
The removal of organic dyes from wastewater using manganese dioxide (MnO 2 ) and its composites has garnered significant attention, but recycling them remains challenging. In this study, MnO 2 was combined with polypropylene melt-blown nonwoven material (PP MB) in a simple way to prepare a composite material, which makes MnO 2 easy to be recycled and reused. MnO 2 with sea urchin-like structure were synthesized using a hydrothermal method and subsequently anchored onto the surface of PP MB modified by polydopamine (PDA) in various loading concentration, resulting in the preparation of MnO 2 @PP MB for removing organic dyes from wastewater. The size of the synthesized MnO 2 is about 6 μm and its specific surface area is 21.73 m 2 /g. When the loading concentration of MnO 2 is 1 mg/mL, the pH of adsorption solution is 3, and the adsorption solution temperature is 25 °C, the removal efficiencies of MnO 2 -1@PP MB for rhodamine B (RhB), methyl blue (MB), methyl orange (MO), and Carmine (CRM) in water all are achieved 99.00% in an impressive rate. Remarkably, even after undergoing twenty adsorption-desorption cycles, the removal efficiency for of MnO 2 -1@PP MB for RhB remained consistently around 99.00%. Furthermore, it was found that the removal behavior of MnO 2 @PP MB for RhB follows the pseudo-second-order kinetic model, meaning that is the adsorption process is primarily driven by chemical interactions. Compared to pristine PP MB, the mechanical properties of MnO 2 -1@PP MB just slightly decrease.
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
危险品化学品经营许可证（带存储）