JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Aijuan Xie,Feng Tao,Chao Jiang,Wenliang Sun,Yanfang Li,Lina Hu,Xiang Du,Shiping Luo,Chao Yao
The different crystallographic structures of manganese dioxide (α-MnO 2 , β-MnO 2 , γ-MnO 2 and δ-MnO 2 ) were prepared via simple and feasible methods. Among four crystallographic structures, γ-MnO 2 exhibited the best electrochemical property and was chosen to compound γ-MnO 2 /polyaniline (PANI) composite electrode through in situ synthesis techniques. The as-prepared samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). The electrochemical properties of as-prepared samples influenced by the different mass ratios, scan rates, and current densities were mainly investigated by cyclic voltammetry (CV), galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS), and cycle life, respectively. The results showed that the specific capacitance can be up to 493 F g − 1 as mass ratio of γ-MnO 2 /PANI was 1:5 at current density of 0.5 A g − 1 , suggesting the γ-MnO 2 /PANI (1:5) composite as an electrode material for super capacitors has great development prospects.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Ling Zhang,Qi Liu,Yuxin Wang,Chunling Xu,Jiaying Bi,Daobin Mu,Borong Wu,Feng Wu
The practical application of high energy density and cost-effective lithium-sulfur batteries is still impeded by such factors as insulation nature of sulfur/lithium sulfides and poor cycling lifespan. Here, an integrated sulfur-containing cathode (S cathode) with modified γ-MnO 2 as the sulfur host is fabricated to address the capacity decline during cycling. When coupled with pre-lithiation and molybdenum doping, the electronic and ionic conductivity of the modified γ-MnO 2 host is enhanced, which reduces the cycling voltage hysteresis of the S cathode. The modified γ-MnO 2 shows strong chemisorption with the intermediate polysulfides that are generated unavoidably during lithium ions intercalation/deintercalation of a S cathode, and presents role of electrochemical catalysis for discharge/charge process to accelerate the redox kinetics of the polysulfides. Consequently, the prepared S cathode demonstrates highly enhanced performance, with an initial specific capacity of 1441 mAh g −1 at a rate of 0.1C, and a maximum areal capacity of 5.37 mAh cm −2 with sulfur loading of 5.8 mg cm −2 . The cycling stability is superior with a capacity retention of 617.2 mAh g −1 at 2C after 500 cycles, and good rate capability is also achieved. This S cathode offers a potential alternative for high-performance lithium-sulfur batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2019
·Vol. 62
·期 6
·727-731
·
IF 6.085
Zeng Xuecen,Zhang Xuejing,Liu Shuang,Yang Hao,Tao Zhanliang,Liang Jing
The γ-MnO 2 @CNT catalyst was prepared by in situ solid phase synthesis and first applied into sodium-air batteries (SABs). The initial discharge specific capacity of SABs with γ-MnO 2 @CNT catalyst can reach 8804 mA h g −1 and the overpotential gap is only 140 mV, which is better than the batteries that is catalyzed by α-MnO 2 @CNT and pure CNT. Besides, the batteries also exhibit excellent cycle performance, which can keep relatively stable for 246 cycles at 500 mA g −1 and 140 cycles at 1000 mA g −1 .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Xiaoyang Chen,Jian Chen,Yijie Liu,Yang Liu,Yun Gao,Siwei Fan,Xiangxi He,Xiaohao Liu,Chao Shen,Yong Jiang,Li Li,Yun Qiao,Shulei Chou
Metal–CO2 batteries, especially Li–CO2 and Na–CO2 batteries, are regarded as ideal new-generation energy storage systems owing to their high energy density and extraordinary CO2 capture capability. However, the advancement of metal–CO2 batteries is still at an early stage. The problems caused by accumulation of carbonates during charge–discharge cycles, such as large polarization and poor reversibility, restrict their practical application. Therefore, designing efficient catalysts is crucial for promoting the decomposition of carbonate to improve the electrochemical performance of metal–CO2 batteries. Herein, we first adopted sea urchin-like γ-MnO2 as the cathode material for Li/Na–CO2 batteries. Benefiting from the unique structure and excellent catalytic activity of γ-MnO2, the as-prepared Li–CO2 and Na–CO2 batteries can achieve low overpotentials of 1.28 and 1.36 V, respectively, at a current density of 100 mA g–1 with a cutoff capacity of 1000 mA h g–1. The overpotentials are lower than those of most of the state-of-the-art catalysts in previous reports. After 100 and 50 cycles of Li–CO2 and Na–CO2 batteries, respectively, their charging termination voltages remain at around 4.1 and 3.9 V, respectively; such a low charging platform indicates the excellent catalytic activity of the γ-MnO2 cathode on the discharge products. Our findings offer a promising guideline to design efficient electrocatalysts for high-performance metal–CO2 batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Xin Xu,Bolin Xia,Amirreza Gholivand,Xiaoyu Zhang,Yunpeng Zhang,Linhui Liu,Daiqi Ye,Peirong Chen
Selective dissolution is highly promising for tailoring the structures and functions of metal oxides toward various applications. Here, we demonstrate a successful fabrication of porous γ-MnO 2 by selectively dissolving Ca in a CaMnO 3 perovskite (CMO) via dilute HNO 3 treatment. The perovskite-derived γ-MnO 2 (denoted as CMO-72 h) outperformed drastically the pristine CaMnO 3 and a commercial γ-MnO 2 in the catalytic oxidation of NH 3 and NO, two representative gaseous pollutants in the atmosphere. Physicochemical characterization by X-ray photoelectron spectroscopy and temperature-programmed techniques (including H 2 -TPR, O 2 -TPD and NH 3 -TPD) suggests that the excellent catalytic performance of CMO-72 h is associated with its low–temperature reducibility and abundant surface–active oxygen species. Specifically, acid treatment led to the oxidation of Mn 3+ to Mn 4+ on the surface, increasing significantly the Mn 4+ /Mn 3+ ratio from 0.76 (for CMO) to 1.45 (for CMO-72 h) and, meanwhile, generating additional surface oxygen vacancies . As a result, O 2 molecules can be easily adsorbed and activated on the CMO-72 h, leading to improved performance in NH 3 and NO oxidation. This study may offer new opportunities in the synthesis of high-performance Mn oxide catalysts for environmental applications.
研究领域:
环境科学
·
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Xiao Ge,Juntao Liu,Xiangyang Song,Guozhong Wang,Haimin Zhang,Yunxia Zhang,Huijun Zhao
The hierarchical flower-like iron containing γ-MnO 2 hollow microspheres assembled by ultrathin nanosheets have been successfully fabricated via a facile one-step co-precipitation route in the absence of additional templates or surfactants. Structural characterization show that iron element is uniformly incorporated into γ-MnO 2 framework, and no segregated iron oxide appears. The resulting iron containing MnO 2 hollow microspheres exhibit a noticeable enhanced performance for As(III) removal compared to that of the undoped counterparts, accompanied by 102.84 mg/g of the saturated removal capacity towards As(III). The excellent performance for the arsenic removal may be attributed to the unique structural characteristics of highly accessible surface and fully exposed active sites inherited from the hierarchical iron containing γ-MnO 2 samples. The co-existence of oxidation and adsorption is another key factor for the improvement of As(III) removal efficiency, in which manganese dioxide is mainly responsible for oxidizing As(III) to As(V) and ferrous species may serve to the adsorption of the generated As(V), as evidenced by X-ray photoelectron spectroscopy (XPS) analysis. Importantly, the composites exhibit an excellent regenerative ability over three cycles without a significant decrease in its removal efficiency towards As(III). Furthermore, the relatively large micrometer-scale particles can be easily separated by filtration, accompanied by fewer secondary contaminants risks than nanoparticles. Therefore, the fabricated hierarchical Fe-containing γ-MnO 2 hollow spheres in the present study will be an excellent candidate for the arsenic transformation and removal from the contaminated water based on the synergistic effects of effective oxidizing and adsorptive performance, good regeneration together with the convenient separation.
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
Nanoscale Horizons
·
2024
·
IF 8
Yingnan Qin,Tongzhu Han,Ligang Chen,Kexin Yan,Jing Wang,Ning Wang,Baorong Hou
Marine biofouling severely limits the development of the marine economy, and reactive oxygen species (ROS) produced by electrocatalytic antifouling techniques could inactivate marine microorganisms and inhibit the formation of marine biofouling. Compared with an electro-Fenton reaction, a three-electron oxygen reduction reaction (3e− ORR) could generate a hydroxyl radical (˙OH) in situ without the limitation of pH and iron mud pollutants. Herein, Ov-rich γ-MnO2 is designed to enhance the 3e− ORR performance in neutral media and exhibits excellent sterilization performance for typical marine bacteria. DFT calculation reveals that Ov is beneficial to the “end-on” adsorption and activation of O2, and the Mn site could accept the electrons from *OOH and promote its further reduction to form ˙OH; Ov and Mn sites together guarantee the high 3e− ORR efficiency. In addition, liquid chromatography–tandem mass spectrometry (LC–MS/MS) proves the vast formation of ˙OH in the primary reaction stage, which is the key to sterilization. This work explores the reaction mechanism of the 3e− ORR in neutral media and provides the possibility for the application of electrocatalysis technology in the treatment of marine biofouling pollution.
研究领域:
电化学
·
材料科学
·
环境科学
·
海洋生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2026
·
IF 8.3
Wenyue Du,Rongcai Jia,Liang Guo,Yanlu Yang
Accurate and rapid ammonia detection is critical for environmental monitoring and clinical diagnosis of chronic kidney disease. Herein, a highly sensitive room-temperature ionic liquid (RTIL) in electrochemical ammonia sensor based on a Pt-Ru electrode was developed for detecting ammonia concentrations ranging from 0 to 100 ppm. To achieve prolonged operational life and stability, 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([HOETMIM][BF 4 ]) was utilized as the electrolyte. Nickel cobaltite (NiCo 2 O 4 ) and γ-MnO 2 were synthesized separately via hydrothermal methods. The effects of modified ionic liquids on the sensor’s performance were investigated by incorporating different mass fractions of NiCo 2 O 4 and γ-MnO 2 . Comprehensive analyses, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Mapping, energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), confirmed the successful and rational synthesis of the samples. The ammonia sensing performance of the ILs/NiCo 2 O 4 /γ-MnO 2 sensor was studied at room temperature (25°C) using constant potential polarization (it) and electrochemical impedance spectroscopy (EIS) techniques. The testing data demonstrated that the optimized ILs/NiCo 2 O 4 /γ-MnO 2 sensor(5 wt% composite, 1:1 mass ratio) exhibited good sensitivity of 0.10 ± 0.02 μA/ppm, a limit of detection(LOD) of 1 ± 0.2 ppm, and a limit of quantification(LOQ) of 3 ± 0.5 ppm. The response and recovery times show clear difference among different sysrems: pure IL system exhibited 510 s/530 s, 5 wt% composite modified system achieved 12.22 s/3.6 s, and the fastest recorded values in batch tests were 17 s/14.5 s. Compared to traditional ionic liquid sensors, the ILs/NiCo 2 O 4 /γ-MnO 2 sensor demonstrated a significant improvement in ammonia sensing performance, with a selectivity ratio > 10 against common interfering gases.
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Yuming Tu,Gaoyan Shao,Wenjing Zhang,Jianjie Chen,Yixin Qu,Fan Zhang,Shichao Tian,Zhiyong Zhou,Zhongqi Ren
Printing and dyeing wastewater generally has high pH, high turbidity , poor biodegradability , complex composition, and high chroma, which make it one of the most difficult industrial wastewaters to treat. Herein, heterogeneous ozone oxidation technology is applied to oxidize and degrade printing and dyeing wastewater. A metal oxide catalyst supported on activated carbon (γ-MnO 2 /AC) was prepared by hydrothermal synthetic method and shown to enable synergistic catalysis involving MnO 2 metal sites and N/C sites. A simulated methyl orange solution was used to determine the effects of various preparation and operation parameters. The results confirmed that the γ-MnO 2 /AC catalyst exhibited good chemical oxygen demand (COD) removal and reusability. Additionally, γ-MnO 2 /AC demonstrated excellent degradation of the secondary biochemical effluent of printing and dyeing wastewater (COD removal = 72.45% within 120 min). The γ-MnO 2 /AC catalyst was fully characterized, and the mechanism governing its catalytic ozone oxidation process was investigated experimentally.
研究领域:
环境科学
·
催化材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 3
·1728-1737
·
IF 4.036
Zhuo-Rui Li,Xiao-Hui Zhang,Yue-Yue Du,Guo-Zhi Han
In this paper, using hollow silica microspheres as carriers, we developed a facile one-pot method for the preparation of hollow SiO2@MnO2 composite microparticles. Under a certain proportion of hollow silica microspheres and manganese salt, a novel kind of hollow urchin-like SiO2@γ-MnO2 microparticles was obtained. The structure and morphology of the composite microparticles were characterized by XRD, SEM and TEM. On this basis, using rhodamine B and methyl orange as model molecules, the oxidative degradation ability of the hollow SiO2@γ-MnO2 microparticles for organic dyes in water was investigated through UV-vis analysis technology. The urchin-like SiO2@γ-MnO2 microparticles showed excellent performance for the rapid oxidative degradation of organic dyes under acidic conditions. This study indicated that γ-MnO2 loaded on hollow materials can be used as an efficient tool for treating organic dye wastewater, and shows broad application prospects for solving environmental problems in the related industry.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Youn-Jun Lee,Ahyeon Jo,Chang-gu Lee,Eilhann E. Kwon
Minimizing the oxidant input in heterogeneous Fenton-like reactions provides a practical strategy for reducing operational costs and abating secondary pollution. This study used hexagonal boron nitride (h–BN) as a support catalyst for γ–MnO 2 to enhance the persulfate utilization during the oxidative polymerization of phenolic pollutants. Upon peroxymonosulfate (PMS) activation, γ–MnO 2 generated surface-bound PMS, which directly abstracted electrons from pollutants, suppressing excessive oxidant consumption. Simultaneously, the h–BN support enriched bisphenol A (BPA) on the γ–MnO 2 -decorated h–BN (MnBN) surface via intermolecular interactions, accelerating the coupling/polymerization of oxidized pollutant intermediates. Consequently, MnBN achieved a high persulfate utilization efficiency (PUE; 87.7%), surpassing previously reported values, and a six-times-faster BPA removal rate (normalized to Mn content) than that of pristine γ–MnO 2 , along with a high polymerization transfer ratio of 95.3%. The critical role of the fast coupling/polymerization of oxidized intermediates, following direct electron transfer, in achieving a high PUE was systematically validated using structurally analogous phenolic pollutants. This study offers a strategy for dynamically minimizing chemical inputs in advanced oxidation processes and provides mechanistic insights into the interplay between pollutant structure and oxidant consumption.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jiacheng Xu,Shun Wang,Chenyun Zhang,Jing Zhang,Lihua Xu,Yue Shi,Guoqiang Xu,Shuiliang Yao
Catalyst surface active oxygen species have an important influence on plasma catalytic oxidation . However, the reaction process of CO and O 3 migration and transformation on the catalyst surface during discharge at different temperature is still unclear. In this study, β- and γ -MnO 2 are selected to unveil the roles of different oxygen species under in-plasma catalysis configuration at different temperature in CO oxidation. Operando TPR-DRIFTS-MS is used to reveal CO and O 3 oxidation pathways. The results show that O 3 can react with CO at room temperature, and O 3 is also converted to other reactive oxygen species on the catalyst surface. As the temperature increases, the oxygen species of the catalyst itself (Mn O and Mn-O-Mn) can react with CO to form oxygen vacancies (Mn-□-Mn and Mn=□). Mn-□-Mn are beneficial for O 2 decomposition and promotes the regeneration of Mn O and Mn-O-Mn. The carbonate covered on the surface of the catalyst is the rate-determining step of CO oxidation. It is hoped that Mn-based catalysts with more reactive oxygen species and oxygen defects will be prepared to facilitate low-temperature CO oxidation under plasma conditions.
研究领域:
催化化学
·
环境科学
✓ 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）