Crystals
·
2022
·Vol. 12
·期 11
·1600
·
IF 2.67
Kun You,Yifei Yuan,Xiuxian Liao,Wenjun Song,Xuedong He,Huile Jin,Shun Wang
Manganese dioxide is regarded as a promising energy functional material due to its open tunnel structure with enormous applications in energy storage and catalysis. In this paper, α-MnO2with a 2 × 2 tunnel structure and β-MnO2with a 1 × 1 tunnel structure were hydrothermally synthesized, which possess characteristic tunnel structures formed by the interconnected unit structure of [MnO6] octahedrons. With regards to their different tunnel dimensions, the specific mechanism of ion intercalation in these two phases and the effect on their performance as aqueous Zn-MnO2battery cathodes are explored and compared. Comprehensive analyses illustrate that both α-MnO2and β-MnO2provide decent capacity in the aqueous battery system, but their intrinsic stability is poor due to the structural instability upon cycling. At the same time, experiments show that α-MnO2has a better rate performance than β-MnO2under larger currents, thus implying that the former has a broader application in this aqueous battery system.Keywords:α-MnO2and β-MnO2nanostructures;aqueous zinc batteries;electrochemical characterization
研究领域:
材料科学
·
电化学
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DOI
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 7
·2032-2042
·
IF 2.372
Wang Ying,Shen Shuguang,Li Meina,Sun Yujuan,Li Binbin,Ma Xueping,Zhou Zijian,Guo Chenyuan
Abstract MnO 2 was screened from various metal oxides and different crystal structures of MnO 2 were prepared, which were used to hydrolyze urea process wastewater for energy conservation and environmental protection. The characterizations of XRD, SEM, Raman, FT-IR, XPS and H 2 -TPR were employed and the hydrolysis experiments were carried out, demonstrating that oxygen vacancy on the surface of MnO 2 might be the catalytic activity source on urea hydrolysis. By optimizing reaction influencing factors, the residual urea concentration reduced to 1.61 mg/L over α -MnO 2 , far below the effluent standard. Meanwhile, the temperature of heterogeneous hydrolysis over α-MnO 2 dropped drastically compared with that of thermal hydrolysis. Further, the kinetic parameters of hydrolysis were obtained over α -MnO 2 . And α -MnO 2 also showed excellent recycling ability on the reused test. Graphical Abstract
Effect of different crystal structures MnO2 on urea degradation rate. (Catalyst dosage is 50 g/L, reaction time is 60 min, temperature is 165oC.)
研究领域:
环境化学
·
催化科学
·
废水处理
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材料化学
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绿色能源
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DOI
高影响因子
CATALYSIS COMMUNICATIONS
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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
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催化
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水处理
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高影响因子
CHINESE SCIENCE BULLETIN
·
2012
·Vol. 57
·期 32
·4210-4214
·
IF 1.321
Zhang LeiLei,Wang ZhongLi,Xu Dan,Xu JiJing,Zhang XinBo,Wang LiMin
Lithium-air (Li-air) batteries have attracted worldwide attention due to their high energy density (11140 Wh kg −1 ) comparable to gasoline. In this work, we have synthesized the α-MnO 2 hollow clews via a simple method and characterized them by X-ray diffraction and scanning electron microscope. Interestingly, cycle performance of Li-air batteries is improved greatly when using the α-MnO 2 hollow clews as the catalyst. The first discharge capacity is 596 mAh g −1 , and the charge capacity is 590 mAh g-1 at the current density of 0.1 mA cm −2 between 2.0 and 4.2 V using the Vulcan XC-72 as the carbon material. Additionally, by re-assembling new batteries with the used lithium foil, separators and cathode separately, we find that the cathode is the key role to end the Li-air battery life.
研究领域:
材料科学
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电化学
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储能技术
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纳米材料
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DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2022
·
IF 8.431
Yusong Yang,Ying Zhao,Yuan Zong,Ruiqi Wu,Mingyi Zhang,Jing Feng,Tong Wei,Yueming Ren,Jun Ma
Developing high-efficiency catalysts for peroxymonosulfate (PMS)-based advanced oxidation processes is important for eliminating pollutants in water. Herein, α-MnO 2 with major exposed {110} and {100} facets prepared via a hydrothermal method were used as catalysts to activate PMS for the degradation of Orange Ⅰ (OⅠ). α-MnO 2 -100, with more abundant surface hydroxyl groups and greater reductive ability, performed remarkably better than α-MnO 2 -110 for degrading OⅠ. OⅠ removal of 86.20% was obtained in the α-MnO 2 -100/PMS system. The apparent rate constant of OⅠ removal over α-MnO 2 -100 was 2.11 times higher than that of α-MnO 2 -110. The effects of PMS concentration, catalyst dosage, OⅠ concentration, initial pH, anions and humic acid (HA) on OⅠ degradation in the α-MnO 2 -100/PMS system were systematically investigated. Quenching experiments and electron paramagnetic resonance (EPR) demonstrated that SO 4 • − , •OH, O 2 • − and 1 O 2 were the reactive oxygen species (ROS) in the α-MnO 2 -100/PMS system. Moreover, the possible degradation pathway of OⅠ in the α-MnO 2 -100/PMS system was proposed. This work provides an ideal metal oxide catalyst for sewage remediation.
研究领域:
环境科学
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化学工程
·
水处理
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DOI
PubMed
高影响因子
Batteries-Basel
·
2024
·Vol. 10
·期 6
·189
·
IF 4.6
Libo Song,Yuanyue He,Zhendong Li,Zhe Peng,Xiayin Yao
Sluggish transfer kinetics caused by solid–solid contact at the lithium (Li)/solid-state electrolyte (SE) interface is an inherent drawback of all-solid-state Li metal batteries (ASSLMBs) that not only limits the cell power density but also induces uneven Li deposition as well as high levels of interfacial stress that deteriorates the internal structure and cycling stability of ASSLMBs. Herein, a fast Li+transfer scaffold is proposed to overcome the sluggish kinetics at the Li/SE interface in ASSLMBs using an α-MnO2-decorated carbon paper (CP) structure (α-MnO2@CP). At an atomic scale, the tunnel structure of α-MnO2exhibits a great ability to facilitate Li+adsorption and transportation across the inter-structure of α-MnO2@CP, leading to a high critical current density of 3.95 mA cm−2at the Li/SE interface. Meanwhile, uniform Li deposition can be guided along the skeletons of α-MnO2@CP with minimized volume expansion, significantly improving the structural stability of the Li/SE interface. Based on these advantages, the ASSLMBs using α-MnO2@CP protected the Li anode and can stably cycle up to very high charge/discharge rates of 10C/10C, paving the way for developing high-power ASSLMBs.
研究领域:
材料科学
·
电化学
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2022
·Vol. 29
·期 29
·44732-44745
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IF 5.19
Wang Zhijie,Bao Jianguo,Du Jiangkun,Luo Liting,Xiao Guangfeng,Zhou Ting
Pollutant degradation via periodate ( \({\text{IO}}_{4}^{-}\) ) and transitional metal oxides provides an economical, energy-efficient way for chemical oxidation process in environmental remediation. However, catalytic activation of periodate by manganese dioxide and the associated mechanism were barely investigated. In this study, four MnO 2 polymorphs (α-, β-, γ- and δ-MnO 2 ) were synthesized and tested to activate \({\text{IO}}_{4}^{-}\) for the degradation of sulfamethoxazole (SMX). The reactivity of different MnO 2 structures followed the order of α-MnO 2 > β-MnO 2 > γ-MnO 2 > δ-MnO 2 , suggesting that the particular crystalline structure in α-MnO 2 would exhibit higher activities via \({\text{IO}}_{4}^{-}\) activation. Herein, in α-MnO 2 / \({\text{IO}}_{4}^{-}\) system, 91.1% of SMX was eliminated within 30 min with degradation rate constant of 0.0649 min −1 , and the neutral pH exhibited higher efficiency in SMX degradation compared with acidic and alkaline conditions. Singlet oxygen ( 1 O 2 ) was unveiled to be the dominant ROS according to the results of electron paramagnetic resonance, chemical probes and radical quenching experiments, whereas \({\mathrm{O}}_{2}^{\bullet -}\) and • OH were mainly acted as a free-radical precursor. Six oxidation products were identified by LC–MS, and the elimination of sulfonamide bond, hydroxylation and direct oxidation were found to be the important oxidation pathways. The study dedicates to the mechanistic study into periodate activation over alpha-MnO 2 and provides a novel catalytic activation for selective removal in aqueous contaminants.
研究领域:
环境科学
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化学工程
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污染控制
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DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Jiajie Li,Quan Kuang,Gang Wang,Qiuchen Lu,Pan Jiang,Qinghua Fan,Youzhong Dong,Yanming Zhao
To meet the application requirements of different scenarios, expanding the selection of cathode materials is a crucial step for the development of aqueous zinc-ion batteries (AZIBs). Manganese phosphates are a type of important and representative cathodes for rechargeable batteries, but they are rarely reported in AZIBs due to their electrochemical sluggishness in aqueous zinc electrolyte. Herein, carbon coating technic and galvanostatic stimulation process are combined to solve the issue and obtain an electrochemically active Na 3 Mn 2 (P 2 O 7 )(PO 4 ) as cathode material for AZIBs. Carbon coated Na 3 Mn 2 (P 2 O 7 )(PO 4 ) (NMPP@C) is synthesized by using a liquid-phase method assisted with freeze-drying process. After galvanostatic stimulation (100 mA g −1 for 5 cycles and following at 10 mA g -1 ), the originally inactive NMPP@C cathode shows a peak capacity of 150 mAh g -1 and then stabilizes at 90 mAh g −1 with a discharge plateau at 1.45 V vs. Zn 2+ /Zn. It is found that the NMPP@C cathode undergoes a structural decomposition during stimulation process, then α-MnO 2 and Zn 2 P 2 O 7 •5H 2 O jointly serve as electrochemical reaction agents eventually. The electron/proton host (α-MnO 2 ) and the Zn 2+ host (Zn 2 P 2 O 7 •5H 2 O) are generated from the same conductive matrix of NMPP@C, which guarantees a satisfactory rate ability and a decent cycle performance in AZIBs.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
Advanced Science
·
2025
·Vol. 12
·期 34
·e04489
·
IF 14.1
Junyu Lu,Lei Xu,Cheng Xie,Chang Zhang,Zhaohui Han,Yiyao Ren,Renchao Che
The advancement of wireless communication technologies necessitates materials that absorb electromagnetic waves and shield against electromagnetic interference. The research is propelled by the necessity to develop materials that possess both properties. Here, an electromagnetic wave-absorbing material that synergistically regulates dielectric and magnetic properties is developed. The material features a nanowire fabric/multilayer composite structure of expanded graphite@α-MnO 2 (EG@MO). The manganese oxide nanowires are prepared in situ on the surface of multilayer expanded graphite via microwave-assisted hydrothermal synthesis. A rapid microwave activation process is subsequently performed to convert manganese oxide-hydroxide, elevating its oxidation state, and transforming it from a non-magnetic form to the magnetic α-MnO 2 . The EG@MO exhibits exceptional electromagnetic wave absorption capabilities, achieving a reflection loss value of −75.56 dB, with a low filler ratio of 7 wt.% and an ultrathin thickness of 1.48 mm. This high-performance electromagnetic absorption material, fabricated by integrating magnetic manganese dioxide nanowires with multilayer expanded graphite, shows excellent widespread applications.
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PubMed
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Xinsheng Luo,Heng Liang,Fangshu Qu,An Ding,Xiaoxiang Cheng,Chuyang Y. Tang,Guibai Li
Catalytic membrane, due to its compact reactor assembling, high catalytic performance as well as low energy consumption, has proved to be more attractive for wastewater treatment . In this work, a free-standing α-MnO 2 @CuO membrane with hierarchical nanostructures was prepared and evaluated as the catalytic membrane to generate radicals from peroxymonosulfate (PMS) for the oxidative degradation of organic dyes in aqueous solution. Benefiting from the high mass transport efficiency and the hierarchical nanostructures, a superior catalytic activity of the membrane was observed for organic dyes degradation. As a typical organic dye, more than 99% of methylene blue (MB) was degraded within 0.23 s using dead-end filtration cell. The effects of flow rate, PMS concentration and buffer solution on MB degradation were further investigated. Besides MB, the catalytic membrane also showed excellent performance for the removal of other dyes, such as congo red, methyl orange, rhodamine B, acid chrome blue K and malachite green. Moreover, the mechanism study indicated that OH and SO 4 - generated from the interaction between PMS and Mn/Cu species with different oxidation states mainly accounted for the dyes degradation. The catalytic filtration process using α-MnO 2 @CuO catalytic membrane could provide a novel method for wastewater purification with high efficiency and low energy consumption.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Jiang Dai,Yibo Zhang,Shidong Li,Shaohua Zhu,Shuhan Jin,Weina Xu,Lei Zhang
Iron doping regulates lattice strain to stabilize the manganese dioxide framework. • Modifying the local structure suppresses manganese dissolution during cycling. • Strain modulation accelerates calcium storage kinetics and improves robustness. • The optimized cathode delivers high capacity and long cycle life. Calcium-ion batteries (CIBs) have attracted increasing attention owing to the natural abundance and potentially low cost of calcium resources. However, practical CIBs cathodes are broadly hindered by sluggish Ca 2+ diffusion, large polarization, and structural instability upon repeated (de)intercalation. Among Mn-based candidates, α-MnO 2 exhibits a low Ca 2+ diffusion barrier, yet its structure suffers irreversible damage during Ca 2+ insertion/extraction. Herein, we propose a Fe-doping strategy to reconstruct the tunnel skeleton of Mn octahedra in α-MnO 2 , which toughens the lattice and regulates its electronic properties, thereby inhibiting the Jahn-Teller effect and preventing Mn dissolution. The strategic incorporation of Fe induces targeted lattice strain, maintaining the long-range skeletal integrity while precisely modifying short-range local distortions. This strain-driven regulation significantly expedites Ca 2+ transport, yielding a diffusion coefficient of 1.24 × 10 −9 cm 2 s −1 , which is the highest recorded value among Mn-based CIB cathodes. Consequently, the optimized Fe-doped α-MnO 2 delivers high rate performance, achieving capacities of 201, 161, 145, 132, and 111 mAh g −1 at 0.1, 0.2, 0.3, 0.5, and 1.0 A g −1 , respectively. Furthermore, it exhibits a long-term cycle life by retaining 74 mAh g −1 after 3000 cycles at 1 A g −1 , providing a rational design paradigm for advanced Mn-based cathodes in CIBs.
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2026
·
IF 8.4
Ying Li,Fangyuan Qiu,Wanyou Huang,Xuesong Tian,Limei Wang,Ruixia Chu,Hang Li,Yibo Gao
Developing low-cost, high-performing non-noble-metal catalysts for the oxygen reduction reaction (ORR) to replace Pt-based catalysts for practical metal-air batteries remains an enormous challenge. Herein, Co 3 O 4 /α-MnO 2 /C composite catalysts with different mass ratios are synthesized, and a heterostructured Co 3 O 4 /α-MnO 2 /C catalyst is successfully constructed. Benefiting from the synergistic interaction between Co 3 O 4 and α-MnO 2 , together with the enhanced conductivity imparted by the carbon support, the catalyst exhibits outstanding electrocatalytic activity. Furthermore, derivative analysis of the LSV curves is employed to accurately determine the ORR onset potential and half-wave potential, providing a quantitative approach for evaluating the electrochemical activity of the Co 3 O 4 /α-MnO 2 /C catalyst. Furthermore, a Zn-air battery driven by the Co 3 O 4 /α-MnO 2 /C catalyst shows excellent electrochemical performance, delivering a high open-circuit voltage of 1.458 V and long-term cycling stability for 300 h. Notably, its overall performance is close to that of commercial Pt/C catalysts. This work highlights the considerable promise of non-noble-metal catalysts for renewable energy storage and conversion applications.
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高影响因子
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