CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Lingbing Wu,Shan Wang,Yao Niu,Zhengyao Sun,Xianghua Yao,Youlong Xu
LiNi 0.5 Mn 1.5 O 4 (LNMO) is a high-profile cathode material for lithium-ion batteries with high voltage and high specific energy. However, its practical application is severely hindered by the dissolution of Mn, primarily induced by the Jahn-Teller effect, which leads to significant capacity degradation, especially under high current densities. In this research, LiNi 0.5-7/3x Cu x Al x Mn 1.5-7/3x Ti x V x O 4 (x = 0, 0.5 %, 1 %, 3 %) was synthesized via a sol–gel method employing a multivalent ion co-doping strategy, denoted as CATV. X-ray diffraction analyses that the increase in the (311)/(400) peak ratio of CATV-1 % indicates a higher concentration of Mn 3+ , which enhances the structural disorder of the material, thereby improving its electronic conductivity. By improving the ratio of the (110) plane, which is perpendicular to the lithium-ion diffusion pathway, the lithium-ion diffusion coefficient was enhanced by three orders of magnitude. Furthermore, the Mn dissolution issue originating from the (111) plane was mitigated which shows in XRF that the Mn content deposited on the negative lithium sheet was reduced by 50 %. Specifically, it delivered specific capacity of 136.2 mAh·g −1 at 0.1C and maintained 81.74 % of its capacity after 300 cycles at 1C. Under 20C charge–discharge condition, it reached 108 mAh·g −1 , doubling that of the undoped sample. These findings provide new possibilities for the commercial application of CATV materials.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Qianlin Huang,Puzhen Zhao,Weiwei Wang,Lu Lv,Weiming Zhang,Bingcai Pan
Cost-efficient and durable manganese-based catalysts are in great demand for the catalytic elimination of volatile organic compounds (VOCs), which are dominated not only by the nanostructures but also by the oxygen vacancies and Mn–O bond in the catalysts. Herein, a series of nanostructured Co–Fe-doped-δ-MnO2 catalysts (Co–Fe-δ-MnO2) with high dispersion were in situ fabricated by employing metal–organic-frameworks (MOFs) as reducing agents, dopants, and templates all at the same time. The as-obtained Co–Fe-δ-MnO2-20% catalyst exhibited robust durability and high catalytic activity (225 °C) for toluene combustion even in the presence of 5 vol % water vapor, which is 50 °C lower than that of pristine δ-MnO2. Various characterizations revealed that the homogeneously dispersed codoping of Co and Fe ions into δ-MnO2 promotes the generation of oxygen vacancies and weakens the strength of the Mn–O bond, thus increasing the amount of adsorbed oxygen (Oads) and improving the mobility of lattice oxygen (Olatt). Meanwhile, due to successfully inheriting the framework structures of MOFs, the obtained catalyst exhibited a high surface area and three-dimensional mesoporous structure, which contributes to diffusion and increases the number of active sites. Moreover, in situ DRIFTS results confirmed that the toluene degradation mechanism on the Co–Fe-δ-MnO2-20% follows the MVK mechanism and revealed that more Oads and high-mobility Olatt induced by this novel method contribute to accumulating and mineralizing key intermediates (benzoate) and thus promote toluene oxidation. In conclusion, this work stimulates the opportunities to develop Co–Fe-δ-MnO2 as a class of nonprecious-metal-based catalysts for controlling VOC emissions.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Daqin Chen,Gaoliang Fang,Xiao Chen
Tunability of emitting colors of perovskite quantum dots (PQDs) was generally realized via composition/size modulation. Due to their bandgap absorption and ionic crystal features, the mixing of multiple PQDs inevitably suffers from reabsorption and anion-exchange effects. Herein, we address these issues with high-content Mn2+-doped CsPbCl3 PQDs that can yield blue-excitable orange Mn2+ emission benefited from exciton-to-Mn energy transfer and Cl-to-Br anion exchange. Silica-coating was applied to improve air stability of PQDs, suppress the loss of Mn2+, and avoid anion-exchange between different PQDs. As a direct benefit of intense multicolor emissions from Mn2+-doped PQD@SiO2 solid phosphors, a prototype white light-emitting diode with excellent optical performance and superior light stability was constructed using green CsPbBr3@SiO2 and orange Mn: CsPb(Cl/Br)3@SiO2 composites as color converters, verifying their potential applications in the field of optoelectronics.
研究领域:
材料科学
·
光电技术
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纳米技术
·
光子学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Yanchao Li,Can Wang,Shuang Pan,Xin Zhao,Ning Liu
Fe/Mn@carbon cloth (CC) was successfully fabricated through high-temperature shock (HTS) technique and used as cathode modification in heterogeneous electro-Fenton (hetero-EF) process for methylisothiazolinone (MIT) degradation. The nanocrystalline on Fe/Mn@CC electrode is doped with Fe and Mn oxides and coated with carbon layer, which could markedly enhance the electrocatalysis with high electro-chemical active area and low resistance. Fe/Mn@CC modified cathode can efficiently in-situ produce and activate H 2 O 2 , showing high electrocatalytic activity to MIT degradation. The 95.2% MIT degradation with in 100 min were achieved under the condition of 30 mA current, 0.75 L min −1 aeration intensity and initial pH = 3. Based on the CV curves and stability test, the high degradation activity revealed the kinetically beneficial regeneration of Fe II /Mn II in Fe/Mn@CC and activation of H 2 O 2 . The electron transfer between Fe II/III and Mn II/III , together with the direct Fe II /Mn II regeneration on the cathode, could markedly promote the H 2 O 2 utilization, and eventually lead to MIT degradation.
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DOI
PubMed
高影响因子
Research
·
2022
·
IF 11.036
Xuefei Xu,Qingming Deng,Hsiao-Chien Chen,Muhammad Humayun,Delong Duan,Xia Zhang,Huachuan Sun,Xiang Ao,Xinying Xue,Anton Nikiforov,Kaifu Huo,Chundong Wang,Yujie Xiong
Electrocatalytic urea oxidation reaction (UOR) is regarded as an effective yet challenging approach for the degradation of urea in wastewater into harmless N2 and CO2. To overcome the sluggish kinetics, catalytically active sites should be rationally designed to maneuver the multiple key steps of intermediate adsorption and desorption. Herein, we demonstrate that metal-organic frameworks (MOFs) can provide an ideal platform for tailoring binary active sites to facilitate the rate-determining steps, achieving remarkable electrocatalytic activity toward UOR. Specifically, the MOF (namely, NiMn0.14-BDC) based on Ni/Mn sites and terephthalic acid (BDC) ligands exhibits a low voltage of 1.317 V to deliver a current density of 10 mA cm-2. As a result, a high turnover frequency (TOF) of 0.15 s-1 is achieved at a voltage of 1.4 V, which enables a urea degradation rate of 81.87% in 0.33 M urea solution. The combination of experimental characterization with theoretical calculation reveals that the Ni and Mn sites play synergistic roles in maneuvering the evolution of urea molecules and key reaction intermediates during the UOR, while the binary Ni/Mn sites in MOF offer the tunability for electronic structure and d-band center impacting on the intermediate evolution. This work provides important insights into active site design by leveraging MOF platform and represents a solid step toward highly efficient UOR with MOF-based electrocatalysts.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2024
·Vol. 9
·期 1
·109-121
·
IF 6
Xiaojuan Shen,Shouyan Sun,Pengwei Liu,ManLin Wei
3D foam-like composites with a large specific surface area and a well-distributed interconnected pore structure have been recognized as promising materials for energy storage devices. In this study, a novel composite electrode (PEUS-Mn-PS) consisting of a 3D foam-like PEUS matrix embedded with manganese dioxide (MnOx) was prepared using a simple and facile method. The PEUS matrix was fabricated by incorporating poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and water polyurethane (PU), where a sacrificial template of poly(3,4-ethylenedioxythiophene) (PEDOT)-decorated Ni foam (NF) was utilized. Specifically, surface modification of NF with a thin layer of PEDOT resulted in the formation of a more regular 3D interconnected scaffold of PEU with more hydrophilic surface, facilitating homogeneous formation of the electrode materials and electrolyte infiltration. Benefiting from the high conductivity of PEDOT:PSS, large surface area provided by PEU, and high capacity offered by MnOx, the resulting flexible PEUS-Mn-PS electrode exhibited an exceptional areal specific capacitance of 681.7 mF cm−2 (∼486.9 F g−1) at 1 mF cm−2, much larger than 358.9 mF cm−2 of the PUS-Mn-PS electrode prepared without PEDOT modification and 318.7 mF cm−2 of the NF-Mn electrode synthesized through direct electrodeposition of MnOx on NF. The resulting PEUS-Mn-PS electrode allowed the assembled solid-state symmetric flexible SC to achieve an impressive energy density of 0.043 mW h cm−2 at a power density of 2.24 mW cm−2, while maintaining excellent electrochemical performance even under various bending angles. This work provides a new approach to designing high-performance flexible SC electrode materials using a simple, cost-effective, and environmentally friendly method.
研究领域:
材料科学
·
能源存储技术
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Fan Feng,Yan Yan
The electric field in ferroelectric ceramics can induce notable deformations or strains based mainly on the electrostrictive effect if the driving field is sufficiently large (normally larger than the coercive field). Therefore, a large electrostrictive effect is highly desired to achieve a high strain output. In the present work, 0.5Ba(Zr 0.2 Ti 0.8 )O 3 -0.5(Ba 0.7 Ca 0.3 )TiO 3 (BCZT50) ferroelectric ceramics doped with different numbers of Mn ions were synthesized and their dielectric and ferroelectric properties were studied to comprehensively evaluate the electrostrictive effect in this system. The doping levels were set as 0.0025, 0.005, 0.01, and 0.02. It was found that Mn ions could lower the temperature corresponding to the maximum permittivity, T m , drastically and induce diffuse phase-transition behaviors simultaneously. Most importantly, a purely electrostrictive effect with a longitudinal electrostrictive coefficient, Q 33 , as large as 0.0466 m 4 /C 2 was observed between 22 and 80 °C. The Q 33 of Mn-doped BCZT50 ceramics is much higher than some representative lead-based and lead-free ferroelectric ceramics. In this paper, a potential lead-free ferroelectric system with a large electrostrictive effect, which has potential applications in electrostrictive actuators, is reported.
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产品关联
DOI
高影响因子
OPTIK
·
2019
·
IF 1.914
Benze Wu,Jin Li,Qiang Li
The Mn-doped nano-ZnO powder was successfully synthesized via co-precipitation and vacuum annealing and the scanning electron microscopy (SEM), X-ray diffracton (XRD), ultraviolet visible absorption (Uv–vis) and photoluminescence (PL) of as-synthesized samples were characterized. The SEM and XRD show that the morphology of the synthesized samples was wurtzite nanosheets and nanoparticles at low doping concentration and with increasing Mn-doping concentration, mainly became to nanoparticle with a size of about 50nm. All of the ultraviolet absorption edges of Mn-doped ZnO have blue shift from Uiv-vis spectra and PL spectra show that Mn-doping significantly enhance the visible excitation band compared with pure ZnO, which indicates that Mn-doping not only produces elemental energy levels, but also affects the intrinsic defect energy levels of ZnO.
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产品关联
DOI
高影响因子
Coatings
·
2017
·Vol. 7
·期 6
·78
·
IF 2.175
Shengzhong Jin,Shichao Zhao,Jiaxin Weng,Yanfei Lv
Molybdenum disulphide (MoS2) monolayer is a two-dimensional semiconductor material with potential applications in nano electronic devices. However, it is still a challenge to reproducibly synthesize single layer MoS2in high quality. Herein, we report the growth of monolayer of MoS2on the SiO2/Si substrate with manganese heterogeneous nucleation. It was shown that the Mn promotes the growth of monolayer MoS2via heterogeneous nucleation. The growth temperature range expanded two-fold, the nucleation density increased as well. The monolayer prepared in the presence of Mn exhibits a unique red emission peak at 732 nm at room temperature compared to the sample in the absence of Mn.Keywords:molybdenum disulphide;heterogeneous nucleation;growth;photoluminescence
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Rui Huang,Shaohua Luo,Qi Sun,Xin Yan,Haoran Zhang,Lixiong Qian,Xin Liu,Xingzhong Cao,Peng Zhang,Shengxue Yan
Fe/Mn-based cathode is considered a viable choice for sodium-ion batteries (SIBs) because of its affordability and high theoretical capacity. Nonetheless, bad actually comprehensive performance still impede its commercial application. In this work, based on the systematic study of P2-Na 2/3 Fe 1/2 Mn 1/2 O 2 cathode materials with fewer Mn vacancies (NFM-Q), we realized a superior rate, cycling performance, air stability and more importantly unraveled the operation mechanism. Specifically, dual function of fewer Mn vacancies were explicitly clarified, which included the effect of shrinking sodium layers and the sodium-ion diffusion promoting effect, as confirmed by combining XRD, XANES, XAFS, EIS and GITT. So Mn vacancy engineering had the potential to break the contradiction between “sodium limiting” based on air-stabilization mechanism and “sodium promoting” based on kinetics. This has rarely been found before. And a series of characterizations strongly declared rapidly cooling rate could effectively regulated the creation of Mn vacancies. As a result, NFM-Q cathode not only delivered outstanding discharge capacity (192.7 mAh/g), cycling stability (123.8 mAh/g, 65 %, after 50 cycles) and energy density (574.0 Wh Kg −1 ), but also possessed splendid air stability (185.8 mA h/g, 61.8 % after 50 cycles and immersion). Moreover, ex-situ XRD and XAS further expounded structural evolution and charge compensation mechanism of NFM-Q cathode, confirming its superior performance. This work might offer fresh understanding about the roles of Mn vacancy engineering, which could open up new possibilities on the material design and the property improvement of Fe/Mn-based cathodes.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Huimin Hu,Qiwu Zhang,Chao Wang,Min Chen,Mengfei Chen
Iron manganese oxide resources are widely derived from the geological structure , and their combinations play an important role in the migration and transformation of arsenic. Iron oxide and manganese oxide exist generally in a mixed state in Fe-Mn oxides synthesized via the well studied co-precipitation methods using potassium permanganate and manganese/iron sulfates. Herein, a newly designed Fe-Mn-O compositing oxide with Fe-MnO 2 , Mn-Fe 2 O 3 , (Fe 0.67 Mn 0.33 )OOH solid solution and FeOOH as the main components, simply through solvent-free mechanical ball milling pyrolusite (MnO 2 ) and ferrihydrite (FeOOH) together has been reported. Atomic-scale integrations by doping Fe and Mn with each other were detected and an adsorption-oxidation bifunctionality was achieved, where Fe-doped MnO 2 served as oxidizer for As(III) and amorphous/ground FeOOH acted as adsorbent first for As(III) and then As(V) from the oxidization. The maximal adsorption for As(III) could reach 44.99 mg/g and over 82.5% of As(III) was converted to As(V). More importantly, high removal ability of arsenic worked in a wide pH range of 2–10.5%, and 87.2% of its initial adsorption-oxidation capacity could be kept even after 5-cycles reuse for treating 20 mg/L As(III) with a dosage at 1 g/L. Together with the enhanced adsorption capacity by the milled FeOOH, surface electron transfer efficiency of the developed Fe-MnO 2 surrounded with Mn-Fe 2 O 3 has been studied for the first time to understand the oxidization effect to As(V). Besides the environment-friendliness of ball milling method, the prepared sample is quite stable without noticeable metal release into solution. Mechanism studies of arsenic removal by the as-prepared Fe-Mn-O oxide provide a new direction for improving the oxidation efficiency of MnO 2 to As(III) based on the widely available cheap Mn and Fe oxides, contributing to the development of advanced oxidization process in the treatment of waste water.
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DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2025
·
IF 4.1
Tai-Shen Yang,Jie Wu,Jing Chi,Jin-Chao Cao
To enhance the synergistic catalytic effect of pyramid Mn 3+ and octahedral Mn 4+ dual crystal fields in SmMn 2 O 5 and improve its oxygen reduction reaction (ORR) performance, Ba-doped Sm 1-x Ba x Mn 2 O 5 (x = 0.1–0.5) catalysts were prepared by hydrothermal method. The substitution of partial Sm 3+ in SmMn 2 O 5 by Ba 2+ leads to the increase in the ratios of Mn 4+ /Mn 3+ and surface adsorbed oxygen/lattice oxygen on the surfaces of Sm 1-x Ba x Mn 2 O 5 . The increase in surface adsorbed oxygen content indicates stronger oxygen adsorption capacity, while the increase in Mn 4+ content facilitates synergistic catalysis of the dual crystal fields. Pyramid Mn 3+ acts as the active site to catalyze ORR, while the increase in octahedral Mn 4+ content enhances the catalytic activity of Mn 3+ by reducing the binding energy between Mn 3+ and oxygen-containing intermediates, weakening the Mn 3+ -O bond, and accelerating the decomposition of hydrogen peroxide generated by Mn 3+ during the ORR process. Sm 0.6 Ba 0.4 Mn 2 O 5 exhibits excellent ORR performance owing to the suitable Mn 4+ /Mn 3+ ratio on its surface, the half-wave potential reaches 0.77 V, higher than the 0.72 V of SmMn 2 O 5 , and the diffusion-limited current density increases from 3.50 mA·cm −2 for SmMn 2 O 5 to 5.03 mA·cm −2 . Moreover, the synergistic catalytic mechanism of the dual crystal fields was well discussed.
研究领域:
材料化学
·
电催化
·
能源材料
·
无机功能材料
·
固体化学
✓ 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）