Materials Today Communications
·
2023
·
IF 3.8
Yuhui Chen,Ruihua Zhang,Zhenhua Hao,Yongchun Shu,Jilin He
In this study, MoO 2 was reduced by an unmixed carbon reduction method. Effects of reduction temperature, reduction time and distance between carbon and MoO 2 on the phase composition of reduction products were investigated. Results show that the phase change during the reduction process are MoO 2 →Mo 2 C→Mo with the increase of temperature. The reduced product is Mo 2 C when reduction temperature is 1000 °C and 1050 °C. Pure Mo can be obtained when the reduction temperature increases to 1100 °C. The reduced product changed from nearly spherical Mo particles with fine molybdenum dioxide particles attached on surface to polyhedron Mo particles with smooth surface when the distance between carbon and MoO 2 decreases from 10 mm to 1 mm. The reaction showed a similar change with the changes of the reaction time. The difference is that there will be residual Mo 2 C in reduced product when reduction time was 1 h. This method of carbon reduction can provide low carbon concentration by controlling the carbon distance to avoid the existence of molybdenum carbide in the product of molybdenum preparation.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOM
·
2022
·Vol. 74
·期 7
·2742-2749
·
IF 2.597
Zhang Rui-Hua,Hao Zhen-Hua,Shi Lin-Yuan,Chen Hao-Tian,Shu Yong-Chun,He Ji-Lin
In this present study, carbothermic reduction process of MoO 3 to produce MoO 2 has been carried to investigate the influences of reaction temperature and distance between activated carbon and MoO 3 on phase composition of reduction products by controlling carbon diffusion. Results show that the reduction degree increases with the increase of temperature and the decrease of distance between activated carbon and MoO 3 . MoO 3 can be completely reduced to MoO 2 at 680°C with the carbon distance of 1 mm. It is found that the transformation from MoO 3 to MoO 2 is a process of crystal cracking and growth by observing the phase transition and morphological evolution during the reduction. The massive MoO 3 is first decomposed into a platelet-shaped MoO x (2.75 < x < 3), then the platelet-shaped MoO x changes into a needle-like shape or irregular platelet-like Mo 4 O 11 , and finally Mo 4 O 11 changes into irregular granular or irregular platelet-like shaped crystals, which form MoO 2 powders.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 9
·3786-3793
·
IF 3.288
Panpan Zhang,Yibin Tong,Mingyuan Zhu,Bin Dai
MoO2/ZrO2–SiO2 catalysts were successfully synthesized using a facile calcination route, and their performance in the oxidative desulfurization process was studied. Experimental results revealed that 5% MoO2/ZrO2–SiO2 exhibited the highest catalytic activity. The properties of the catalysts were investigated using methods such as X-ray photoelectron spectroscopy, Fourier-transform infrared and Transmission electron microscopies. X-ray diffraction confirmed that MoO2 was present in the ZrO2–SiO2 support. Temperature programmed desorption of NH3 proved that the MoO2/ZrO2–SiO2 catalyst has more acid sites. The reaction conditions were optimized in the oxidative desulfurization process. The sulfur removal rate was 99.96% under the optimum reaction conditions of 0.06 g catalyst, 298 K, and O/S = 4, for 30 min. After eight cycles, the activity of the catalyst decreased to 88.65%.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
Carbon Neutralization
·
2025
·Vol. 4
·期 3
·e70013
·
IF 12
Zihua Li,Yao Lu,Mengmeng Liu,Di Xiao,Kehua Dai,Jiangtao Xu,Guangfu Liao,Chunju Li
Molybdenum dioxide (MoO 2 ) is a hopeful anode material for high-performing lithium-ion batteries (LIBs), but the practical application is still impeded due to its huge volume variation and degraded capacity upon the cycling process. Herein, we present a reasonable design and synthesis of amorphous carbon matrix-confined MoO 2 yolk–shell microspheres (MoO 2 /C-YSMs) by a simple solvothermal strategy and in situ carbonizing process. This unique carbon-restrained yolk–shell architecture can not only shorten Li + ion/electron transfer pathways, but also relieve the large volume change of anode materials and further improve battery performance. Profit from steady yolk–shell structure and conductive carbon matrix, the obtained MoO 2 /C-YSMs electrode demonstrates a high reversible specific capacity of 1034 mA h g –1 at 100 mA g −1 and 504 mA h g −1 at 2000 mA g −1 with good rate capability and long cycle performance. The study demonstrates a facile, feasible, and low-cost method to prepare high-performing electrodes via structural design, which reveals the potential of MoO 2 /C-YSMs for using high-performance anode material for LIBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Energy & Environmental Materials
·
2020
·Vol. 5
·期 1
·245-252
·
IF 0
Chunli Wang,Lianshan Sun,Bingbing Tian,Yong Cheng,Limin Wang
As important ingredients in lithium-ion battery, the Coulombic efficiency and power density greatly impact the electrochemical performances. Although recent literatures have reported nano-porous materials to enhance the specific capacities, intrinsic drawbacks such as poor initial Coulombic efficiency and low volumetric capacity could not be avoided. Herein, we propose a strategy to prepare carbon supported MoO 2 spheres used for lithium-ion battery with high volumetric capacity density. A high initial Coulombic efficiency of 76.5% is obtained due to limited solid electrolyte interface film formed on the exposed surface. Meantime, the sample with an optimal carbon content and a proper structural strength reveals a higher reversible capacity of 956 mA h g −1 than the theoretical capacity of crystalline MoO 2 (838 mA h g −1 ) and a high capacity retention ratio of 96.4% after 100 cycles at 0.5 A g −1 . And an effective compaction capacity density (under 5 MPa) of 670 mA h cm −3 of the spheres proves its potential value in practical applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
电池技术
✓ 已验证
DOI
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Guang Yang,Yihang Guo,Xiangjie Bo
Herein, a simple and fast laser-assisted coupling method is used for preparation of rod-like carbon-coated Mo/MoO 2 hybrids at room temperature and air environment. Under high energy of laser and reductive atmosphere caused by precursor decomposition, Mo-polydopamine complex-wrapped MoO 3 rods are quickly converted into nitrogen-doped carbon-coated Mo/MoO 2 rods. Carbon-coated Mo/MoO 2 exhibits high surface area, uniform metal dispersion and appealing hydrogen evolution reaction (HER) catalytic performance in a wide pH range. Carbon-coated Mo/MoO 2 shows overpotential of 134, 108 and 164 mV to deliver current density of 10 mA cm −2 under alkaline, acidic and neutral solution, respectively. Theoretical calculation demonstrates that combination of Mo and MoO 2 into Mo/MoO 2 composite favors the dissociation of water and adsorption of hydrogen. This study not only provides a high-efficiency strategy for preparation of electrocatalysts but also give guidance for development of hybrid electrocatalysts for HER.
研究领域:
材料科学
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电催化
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Zhuangzhi Wu,Min Ouyang,Dezhi Wang,Xinli Liu
The photoelectrocatalytic water splitting of molybdenum disulfide is hindered by the intrinsic large electrical resistance among adjacent layers, serious photo-generated carrier recombination and limited utilization of visible light . Herein, we construct MoS 2 /MoO 2 heterostructures via a facile in situ hydrothermal route, in which a Schottky junction is established between the MoS 2 semiconductor and metallic MoO 2 . As a result, the photoelectrochemical current density of MoS 2 /MoO 2 is enhanced about 1.6 times than that of pure MoS 2 , achieving −10.3 mA cm −2 at −1.8 V vs. SCE, which can be attributed to the reduced electron transfer resistance, enlarged photo-generated carrier separation efficiency and enhanced light absorption due to the presence of metallic MoO 2 .
研究领域:
材料科学
·
物理化学
·
能源化学
·
半导体催化
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 20
·17571-17579
·
IF 2.324
Zhong Canyu,Lai Qi,Liao Xianjie,Li Yufeng,Wu Jinggao
Porous Ti-doped MoO 2 was successfully synthesized through one-pot hydrothermal method and used as an anode material for lithium ion batteries (LIBs). It delivers an initial discharge capacity of 1290 and 410 mAh/g at current density of 20 and 1000 mA/g, respectively. Electrochemical cycle test shows that the discharge capacity of 740 mAh/g can be obtained after 80 cycles at current density of 200 mA/g, with 78.06% capacity retention and almost 100% columbic efficiency. The electrochemical performances are much better than that of other MoO 2 -based materials. This could be assigned to the porous structure that increased contact areas between electrode materials and electrolytes, much faster electron transport confirmed via electrochemical impedance spectroscopy (EIS) analysis and Density functional theory (DFT) calculations.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2021
·Vol. 40
·期 10
·2810-2818
·
IF 4.003
Xu Kun,Liang Xin,Wang Lu-Lu,Wang Yong,Yun Ju-Feng,Sun Yi,Xiang Hong-Fa
Abstract The popularity of lithium–sulfur batteries has been increasing gradually due to their ultrahigh theoretical specific capacity and energy density. Nevertheless, they also have lots of drawbacks to be overcome, such as poor conductivity, severe volume expansion, and serious “shuttle effect”. In this work, reduced graphene oxide/molybdenum dioxide (rGO/MoO 2 ) composite is synthesized and applied to modify polypropylene separator. The modified polypropylene separator introduces synergistic tri-functions of physical adsorption, chemical interaction and catalytic effects, which can inhibit the “shuttle effect” and enhance the electrochemical performances of lithium-sulfur batteries. In the prepared rGO/MoO 2 composite, the polar MoO 2 chemically adsorbs the intermediate lithium polysulfide, while the rGO with good electrical conductivity not only acts as a physical barrier to prevent diffusion of polysulfide ions, but also improves the conversion efficiency of active material intercepted on the separator. As a consequence, the battery assembled with rGO/MoO 2 modified polypropylene separator exhibits a reversible capacity of 757.5 mAh·g −1 after 200 cycles at 0.2C with a negligible capacity decay of 0.207% per cycle, which indicates a good long-period cycling stability. Furthermore, the rate performance and self-discharge suppression are also improved by introducing modified polypropylene separator. It shows that rGO/MoO 2 composite is a promising material for separator modification in lithium-sulfur batteries. Graphic abstract
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2025
·Vol. 31
·期 27
·e202500589
·
IF 3.7
Jinhua Zhou,Tao Ji,Shengyang Xu,Xiong Wang,Juntao Wang,Yating Tang,Yuhong Li,Wenyu Yin,Hongmei Ji,Shaojun Shi,Gang Yang
The development of hierarchical heterostructured materials for sodium-ion batteries (SIBs) remains hindered by suboptimal high-rate cycling performance, primarily due to phase interface pulverization and separation during charge–discharge processes. To address these challenges, we designed a carbon-free hierarchical structure comprising few-layered MoS₂ nanosheets and MoO₂ nanocrystals through precise compositional optimization and rational structural engineering. The heterogeneous components are interconnected through robust S─O covalent bonds, which theoretical calculations and experimental results confirm generate a built-in electric field at the heterointerfaces, significantly enhancing reaction kinetics. Crucially, these covalent bonds stabilize the heterointerfaces, improving structural integrity and mitigating electrode material agglomeration and pulverization. Additionally, the MoS₂/MoO₂ heterostructure enhances Na⁺ adsorption energetics and reduces Na⁺ diffusion barriers, facilitating efficient ion transport. Leveraging its abundant heterointerfaces and stable architecture, the composite delivers exceptional rate performance (432.7 mAh·g⁻¹ at 10 A·g⁻¹) and outstanding cycling stability (nearly 100% capacity retention over 400 cycles at 5 A·g⁻¹). This work provides a strategic framework for designing heterostructured materials with stable interface-rich architectures, advancing the development of high-performance conversion/alloy-type anodes for energy storage applications. Graphical The study designs a carbon-free MoS 2 /MoO 2 heterostructure with abundant heterointerfaces and strong chemical bonding. The formed S─O bonds generate an internal built-in electric field, endowing the heterostructure with metallic conductivity and high Na + adsorption energy. The rational structural design ensures fast reaction kinetics and a stable heterointerface, enabling superior high-rate Na + -ion storage performance.
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产品关联
DOI
PubMed
高影响因子
Nano Energy
·
2021
·
IF 17.881
Zhen Liu,Di Jiang,Linjing Yang,Jiayuan Yu,Xiao Li,Xiaoyan Liu,Lili Zhao,Xiao Li Zhang,Feng Han,Weijia Zhou,Hong Liu
How do the synergistic effects work and which dominate the distribution of active sites, that's an interesting question in mang plasmon-enhanced catalysis. Herein, we put a deep insight into the distribution of active sites and the mechanism of charge transfer at the noble metal-metal oxide interface for accelerating the hydrogen evolution reaction (HER) kinetics. A heterostructure of Au loaded MoO 2 nanosheets (Au-MoO 2 ) is prepared by the light-reduction method. EXAFS analysis demonstrates the tight coupling at Au-MoO 2 interface through the Au-O bond. An enhanced HER activity is observed with an overpotential decrease of (Δη) 176 mV and Tafel slop down to 52.5 mV/dec. KPFM measurement and FEM simulation verify the high local field enhancement at the junction. This field induces the concentrated surface charge through the Au-O bond. DFT calculation confirms the upraises filling of Op orbital in the Au-O bond, thus degrading the hydrogen adsorption energy level for HER kinetics.
研究领域:
催化化学
·
纳米材料科学
·
表面科学
·
物理化学
·
能源化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Xiaoyang Dong,Jinxing Wang,Jingdong Yang,Xiao Wang,Junyao Xu,Xiaofang Yang,Wen Zeng,Guangsheng Huang,Jingfeng Wang,Fusheng Pan
Hybrid Mg/Li-ions batteries (MLIBs), combining the fast kinetics of Li and the advantages of magnesium ion batteries (MIBs), are regarded as one of the most prospective electrochemical energy storage systems. Nevertheless, the electrochemical properties of batteries are generally limited by the diffusion kinetics of highly-polarized divalent Mg ions in the cathode materials. Herein, rutile-type molybdenum dioxide (R-MoO 2 ) was synthesized by the hydrothermal treatment and subsequent thermal treatment and used as the cathode materials in MIBs and MLIBs. The initial discharge capacities of R-MoO 2 cathodes in MIBs and MLIBs are 50 and 253 mAh·g − 1 at the current density of 50 mA·g − 1 , respectively. The specific capacities are 17 and 111 mAh·g − 1 after 100 cycles. The R-MoO 2 cathode possesses good Coulombic efficiency and rate capability in MLIBs. Compared with MIBs, the electrochemical performances of MLIBs were greatly enhanced. The energy storage mechanisms were investigated by the experiments results and density functional theory (DFT) calculations. Moreover, the discharge-charge mechanisms were also explored by ex-situ characterizations. The diffusion/migration of Mg 2+ and Mg storage abilities are improved by introducing the Li + , promoting electrochemical performances. The energy storage mechanisms are Mg 2+ intercalation in MIBs and Mg 2+ /Li + co-intercalation in MLIBs. This work further investigates the energy storage mechanism of MLIBs and provides the theoretical groundwork for the follow-up development of high-performance cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 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）