CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yinyin Zhang,Fangzhong Liu,Ting Song,Yong Pei,Xianyou Wang,Xiongwei Wu,Manjun Xiao,Qi Deng,Bei Long
The electrochemical performances of LiNi 0.5 Mn 1.5 O 4 (LNMO) materials are strongly correlated with the ratio of disordered to ordered phases. Nevertheless, there are few reports on the adjustment of ordered and disordered phase ratio. In this paper, the ratio of ordered to disordered phases in LNMO is successfully adjusted by using a quaternary molten salt, which is proven by XRD refinement, FT-IR, and XPS. Reductive quaternary molten salt and Co doping are favorable for Ni/Mn cation disorder, leading to the increased disordered phase. LNMO with an appropriate ratio of ordered to disordered phases can exhibit enhanced electronic/ionic transfer rate and structural stability, revealed by electrochemical tests and ex situ characterizations. Therefore, the optimized material delivers a reversible capacity of 121 mA h g −1 at 20 mA g −1 and a long cyclic life with 61 mA h g −1 at 1000 mA g −1 over 1200 cycles. The present work offers a new idea for achieving a regulated ratio of ordered to disordered phases in LNMO.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 12
·1664
·
IF 2.7
Yulong Chen,Yuan Chi,Xiao Wu,Cong Lin,Tengfei Lin,Min Gao,Chunlin Zhao,Baisheng Sa
The widespread use of pharmaceuticals and personal care products (PPCPs) in many fields has brought convenience to human lives but has also caused unavoidable environmental pollution issues. In particular, the resistance gene problem resulting from accumulating antibiotics that cannot be fully absorbed by biological individuals has been a concern; thus, it is urgent to find efficient technologies to boost the degradation efficiency of antibiotics in the environment. Here, an ε-MnO2catalyst was prepared by a novel droplet-interface-drying method and utilized as a Fenton-like catalyst for efficiently degrading ciprofloxacin (CIP). The ε-MnO2shell was formed preferentially at the gas–liquid interface and then continued to decompose into ε-MnO2with abundant O vacancies in the air-insulated microcavity. The XPS result confirms that this particular preparation method can regulate the content of O vacancies in the material. Compared with ε-MnO2samples obtained by the direct drying method (ε-MnO2-B), the catalytic performance of ε-MnO2prepared by the droplet-interface-drying method (ε-MnO2-P) is significantly improved. By activating peroxymonosulfate (PMS) with the ε-MnO2-P catalyst, the CIP degradation efficiency can reach 84.1%. The detection and analysis of reactive oxygen species (ROS) in the ε-MnO2-P/PMS oxidation system confirms that ·OH, SO4·−and1O2are the main ROS for CIP degradation. This study highlights the creation of miniature hypoxic space to regulate the content of O vacancies in ε-MnO2, providing a new idea for the synthesis of other O-vacancy-rich materials.Keywords:droplet-interface-drying method;Fenton-like oxidation;ε-MnO2;ciprofloxacin;water purification
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
TEXTILE RESEARCH JOURNAL
·
2023
·
IF 2.3
Qi Wang,Mengfan Wang,Jiali Sun,Xiaolin Zhang,Weichun Chen,Xichen Yu,Wei Fan
With rapid development in the smart wearable field, new-style flexible energy storage devices are necessary to satisfy the demands of flexible smart clothing. Thereinto, fiber supercapacitors present promising application prospects. This work puts forward a facile and reliable strategy to fabricate coaxial fiber electrodes via binary wet spinning, and further assembles them into parallel or twisted nano-MnO2 fiber supercapacitors. In the obtained fiber electrode, a carboxymethylcellulose layer onto nano-MnO2 not only allows the requisite ion exchange between the electrochemical active materials and gel electrolyte, but also plays the role of separator to protect the two fiber electrodes effectively from contacting a short circuit, greatly ensuring the electrochemical stability of the nano-MnO2 fiber supercapacitors. The parallel nano-MnO2 fiber supercapacitor reaches a maximum CL of 19.7 μF/cm, EL of 0.0027 μWh/cm and PL of 1.49 μW/cm; the twisted MnO2 fiber supercapacitor achieves maximum CL, EL and PL of 49 μF/cm, 0.0053 μWh/cm and 1.0 μW/cm, respectively. Besides, the outstanding softness and tensile properties of the obtained nano-MnO2 fiber supercapacitors also guarantee stable electrochemical performance under bending, knotting or other large-distortion situations, which is beneficial to develop a new generation of metal oxide fiber supercapacitors for smart wearable clothing.
研究领域:
材料科学
·
能源存储
·
智能纺织品
✓ 已验证
产品关联
DOI
高影响因子
Journal of Science-Advanced Materials and Devices
·
2023
·
IF 8
Xiaoming Wang,Ling Weng,Yumeng Zhang,Ruize Shen,Xiaorui Zhang,Lizhu Guan,Xue Li,Sheng Ye
Herein, a method is proposed for preparing MnO 2 @carbon core–shell particles and MnO 2 @carbon/polyvinylidene fluoride (PVDF) composite films. The effect of MnO 2 @carbon core–shell particles on the dielectric properties of polymer composites was investigated. Furthermore, a comprehensive dielectric property test was conducted on the composite films. The results reveal that with the addition of MnO 2 @carbon core–shell particles, the dielectric properties of the composite films also improved. The dielectric constant of the 10 wt% MnO 2 @carbon composite is 24.2 at 100 Hz, which is 3 times that of PVDF (7.68). Currently, the energy storage density of the composite film is 4.95 J cm −3 at ∼2300 kV cm −1 . The addition of MnO 2 @carbon core–shell particles effectively improves the energy storage density of PVDF. Based on this result, the influence of the carbon shell on the dielectric properties of the composite thin films is analysed and discussed. The significant improvement in dielectric properties is mainly due to the increased interfacial polarisation induced by the carbon shell. These characteristics of PVDF/MnO 2 @carbon composites indicate that the proposed method is a practical pathway to developing high-performance composites.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Jing Shang,Siyu Jiang,Pei Zhang,Jinsong Fan,Kun Li
Dark-field microscopy (DFM) imaging based on plasmonic metal nanoparticles has garnered significant attention. Here, we exploit the susceptibility of MnO2 to reduction to modulate the local dielectric environment of an Au nanoparticle core through the etching/antietching effects of specific targets on the encapsulated MnO2 shell. The presence of d-penicillamine promotes MnO2 etching, while the chelation of d-penicillamine with Cu2+ effectively inhibits this etching. By recording the Cu2+-induced color shift of scattered light from orange to bright green at the single-particle level and performing the statistical analysis of the green-to-red (G/R) values in DFM images, we achieved quantitative determination of Cu2+ with a wide linear range (0.1–10 μM) and a low limit of detection (4.55 nM). With the facile and reliable Cu2+ assay in real-world samples exemplifying the practicality of the single-particle nanoplasmonic imaging method, this work may inspire future DFM-based investigations of nanoshell etching inhibition processes.
研究领域:
分析化学
·
纳米生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2021
·Vol. 23
·期 2
·1-11
·
IF 2.253
He Yunbing,Pan Xuexue,Kuang Liping,Hu Bo,Zha Qinbing,Chen Xinman
The MnCo 2 O 4.5 @MnO 2 composite nanomaterial was successfully designed and synthesized via successive hydrothermal and subsequent calcination methods, in which MnO 2 nanosheets coated on MnCo 2 O 4.5 nanoneedle arrays were directly grown on Ni foam. Compared with pristine MnCo 2 O 4.5 nanoneedle electrode, MnCo 2 O 4.5 @MnO 2 composite electrode exhibits a high specific discharge capacitance of 1155 F g -1 at a current density of 1.43 A g -1 , the capacitance retention of 93.4% after 5000 cycles, and low initial internal resistance of 1.9 Ω. The results reveal that the rational design of MnCo 2 O 4.5 @MnO 2 electrode with such structure and composition is an effective strategy to improve electrochemical performances of MnCo 2 O 4.5 . Due to unique nanostructure and brilliant electrochemical properties of MnCo 2 O 4.5 @MnO 2 electrode, the fabricated hybrid supercapacitor based on MnCo 2 O 4.5 @MnO 2 positive electrode and activated carbon negative electrode delivers the wide operating voltage window of 1.6 V, a capacitance retention of 87.8% after 8000 continuous charge-discharge cycles at a current density of 1.33 A g -1 , the maximum energy density of 40.8 Wh kg -1 at a power density of 263.9 W kg -1 , and highest power density of 1336.6 W kg -1 to achieve an energy density of 24.4 Wh kg -1 . Herein, the designed MnCo 2 O 4.5 @MnO 2 composite is a distinguished candidate material for hybrid supercapacitor.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 23
·8086-8093
·
IF 5.721
Haoxi Jiang,Debin Kong,Ying Niu,Sheng Wang
MnO2–CoOX catalysts with different Mn/Co ratios were prepared using polyvinyl pyrrolidone (PVP) as an assistant to control the morphology and exposed crystal faces of composite oxides. The physicochemical properties of the catalysts were systematically characterized and the catalytic activity of NH3-SCR and resistance to SO2/H2O were investigated. It was found that the NO conversion over Mn–Co-0.2-PVP was apparently higher compared with that over Mn–Co-X-PVP (X = 0.9, 0.8, 0.6, and 0.4). This can be interpreted in terms of exposed crystal surface (110) and enhanced adsorption of NH3/NO, and better redox performance resulting from higher Co3+/Co2+ ratio. Furthermore, different PVP and HAc additives have different H2O and SO2 resistance. Mn–Co-0.2-PVP showed good resistance to H2O and SO2 poisoning owing to having more low-temperature (∼200 °C) NO adsorption sites, which are beneficial to promote the de-NOX reaction and less affected by SO2.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Xiong Song,Guoping Chen,Suqing Wang,Yuping Huang,Zhouyang Jiang,Liang-Xin Ding,Haihui Wang
Separator modification has been proved to be an effective approach for overcoming lithium polysulfide (LiPS) shuttling in lithium–sulfur (Li–S) cells. However, the weight and stability of the modified layer also affect the cycling properties and the energy density of Li–S cells. Here, we initially construct an ultrathin and lightweight MnO2 layer (380 nm, 0.014 mg cm–2) on a commercial polyethylene (PE) separator (MnO2@PE) through a chemical self-assembly method. This MnO2 layer is tightly anchored onto the PE substrate because of the presence of oxygen-containing groups that form a relatively strong chemical force between the MnO2 nanoparticles and the PE substrate. In addition, the mechanical strength of the separator is not affected by this modification procedure. Moreover, because of the catalytic effect and compactness of the MnO2 layer, the MnO2@PE separator can greatly suppress LiPS shuttling. As a result, the application of this MnO2@PE separator in Li–S batteries leads to high reversible capacity and superior cycling stability. This strategy provides a novel approach to separator surface modification.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 56
·35280-35286
·
IF 3.361
Jingliang Xu,Xinhang Hu,Md Asraful Alam,Gul Muhammad,Yongkun Lv,Minghai Wang,Chenjie Zhu,Wenlong Xiong
Zn/MnO2 batteries, one of the most widely studied rechargeable aqueous zinc-ion batteries, suffer from poor cyclability because the structure of MnO2 is labile with cycling. Herein, the structural stability of α-MnO2 is enhanced by simultaneous Al3+ doping and lignin coating during the formation of α-MnO2 crystals in a hydrothermal process. Al3+ enters the [MnO6] octahedron accompanied by producing oxygen vacancies, and lignin further stabilizes the doped Al3+ via strong interaction in the prepared material, Al-doped α-MnO2 coated by lignin (L + Al@α-MnO2). Meanwhile, the conductivity of L + Al@α-MnO2 improves due to Al3+ doping, and the surface area of L + Al@α-MnO2 increases because of the production of nanorod structures after Al3+ doping and lignin coating. Compared with the reference α-MnO2 cathode, the L + Al@α-MnO2 cathode achieves superior performance with durably high reversible capacity (∼180 mA h g−1 at 1.5 A g−1) and good cycle stability. In addition, ex situ X-ray diffraction characterization of the cathode at different voltages in the first cycle is employed to study the related mechanism on improving battery performance. This study may provide ideas of designing advanced cathode materials for other aqueous metal-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Micro & Nano Letters
·
2020
·Vol. 15
·期 13
·938-942
·
IF 0.975
Pengjiao Zhang,Wei Li
Copper oxide/manganese dioxide (CuO/MnO 2 ) nanocomposites were prepared by a facile microwave-assisted synthesis method in an ordinary household microwave oven and used for electrochemical supercapacitor. The nanocomposites were characterised by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Electrochemical results demonstrate that CuO/MnO 2 nanocomposites have better capacitance performance than pure CuO material. The CuO/MnO 2 nanocomposites have a high specific capacitance of 499.0 F/g at a current density of 0.5 A/g in 6 M KOH electrolyte. In addition, an asymmetric supercapacitor with activated carbon as a negative electrode and CuO/MnO 2 nanocomposite as a positive electrode was also successfully prepared. This asymmetric device exhibits a high energy density of 32.07 Wh/kg at a power density of 375.02 W/kg and fairly good cycling stability.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2018
·
IF 0
Jing Liu,Hongbo Cui,Siyu Yan,Xunan Jing,Daquan Wang,Lingjie Meng
We report a facile fabrication approach for sensitive theranostic nanoprobe - gold [email protected] 2 nanosheets, by which gold nanostars were grown on the surface of MnO 2 nanosheets. Owing to the ability of gold nanostars to absorb light at near infrared (NIR) wavelength, the nanoprobe showed excellent photothermal conversion effect, while exhibited tumor microenvironment-responsive magnetic resonance imaging property due to the redox property of MnO 2 nanosheets. Amazingly, photothermal irradiation experiment showed that the nanoprobe sensitively triggered lung cancer cell death, while produced negligible effect on normal lung epithelial cells. Therefore, these demonstrate that the nanoprobe may have potential application in magnetic resonance imaging-guided photothermal therapy of lung cancer.
研究领域:
纳米技术
·
生物医学工程
·
癌症研究
✓ 已验证
DOI
Small
·
2021
·Vol. 17
·期 45
·2104557
·
IF 13.281
Guolong Wang,Yaling Wang,Boyuan Guan,Jiamei Liu,Yan Zhang,Xiaowei Shi,Cheng Tang,Guohong Li,Yingbo Li,Xiao Wang,Lei Li
MnO 2 -based material is one of the most promising cathode candidates of aqueous zinc-ion batteries (ZIBs), but its commercialization is hindered by the sluggish reaction kinetics and poor structural stability. Herein, a hierarchical framework consisting of core–shell structured carbon nanotubes@K-birnessite-MnO 2 enwrapped by graphene/carbon black bicomponent networks (CNT@KMO@GC) via a simple method for ZIBs is designed and developed. The hierarchical framework characterized with favorable K + preintercalation, δ-phase, and vertically aligned nanoflake arrays of KMO and 3D electrically conductive network shows the enhanced electronic/ionic conductivity and improved wettability with electrolyte, resulting in the fast charge/mass transport and stable structural stability of CNT@KMO@GC. When used as cathode in ZIBs, CNT@KMO@GC exhibits exciting electrochemical performance with remarkable capacity (405.5 mAh g −1 at 0.30 A g −1 ), high rate performance (166.6 mAh g −1 up to 10.0 A g −1 ), and impressive cycling stability (almost no capacity decay after 2000 cycles and 77.3% retention after 10 000 cycles at 10.0 A g −1 ). The energy storage mechanism of CNT@KMO@GC is clarified as H + /Zn 2+ coinsertion/extraction via electrochemical analysis and ex situ characterization. This study offers an innovative paradigm for the advance of ZIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）