RSC Advances
·
2016
·Vol. 6
·期 108
·106230-106236
·
IF 3.289
Ying Che,Xiaoyi Zhu,Jianjiang Li,Jin Sun,Yanyan Liu,Chunde Jin,Chaohong Dong
The sluggish kinetics and large volume expansion occurring during cycle process are critical disadvantages for molybdenum dioxide (MoO2) based anode materials for lithium-ion batteries (LIBs). The design and controllable synthesis of MoO2 based materials with unique hierarchical structure are desired. In this work, we present a one step in situ method to synthesize MoO2/carbon aerogel composites with MoO2 nanoparticles embedded in the carbon aerogel matrix using an environmentally friendly alginate as the carbon precursor. The key feature of our strategy involves the use of a carbon aerogel matrix which facilitates the Li ion transport and offers the space for MoO2 volume expansion during the discharge and charge processes. The composite prepared under optimum conditions, namely a stabilization temperature at 375 °C, exhibited a brilliant performance with a specific capacity of 574 mA h g−1 at a current density of 100 mA g−1, good cycle stability (i.e., a reversible capacity of 490 mA h g−1 at a current density of 200 mA g−1 for 120 cycles), excellent rate capability (remains at 331 mA h g−1 even at a current density of 1000 mA g−1). This finding presents an easy, eco-friendly and efficient strategy for the fabrication of potential high-performance LIBs anodes.
研究领域:
材料科学
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能源存储
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2017
·Vol. 5
·期 2
·446-453
·
IF 4.036
Cuncai Lv,Zhipeng Huang,Qianpeng Yang,Chi Zhang
The development of an effective, non-precious electrocatalyst for hydrogen evolution reaction (HER) is highly desirable for electrocatalytic water splitting and electrochemical/photoelectrochemical water splitting to produce hydrogen. Herein, a facile one-step ultrasonic spray pyrolysis method is developed for the synthesis of MoO2–MoC composite loaded on porous carbon (MoO2/MoC@C), and the MoO2/MoC@C is found to exhibit prominent catalytic activity in the HER. The overpotential required for a current density of 20 mA cm−2 is as small as 133 mV in 0.5 M H2SO4 and 203 mV in 1 M KOH for the MoO2/MoC@C, and the value is superiorly comparable to that of reported metal carbides. The MoO2/MoC@C can work stably both in acidic and basic solution over 30 h with 95% faradaic efficiency in 0.5 M H2SO4 and 93% in 1 M KOH. The synergic effect between MoO2 and MoC is suggested by density functional theory calculations.
研究领域:
材料科学
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电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Xueai Teng,Zibo Wang,Yusong Wu,Yu Zhang,Bo Yuan,Yingying Xu,Rongming Wang,Aixian Shan
Interface engineering is verified as an efficient strategy for enhancing the intrinsic activity of transition metal-based electrocatalysts in alkaline hydrogen evolution reaction (HER). Here, the heterostructural MoO 2 /Ni 3 S 2 nanorod arrays fabricated on nickel foam (MoO 2 /Ni 3 S 2 /NF) are produced by a straightforward and effective hydrothermal approach. Benefiting from interfacial effect and self-supported structure, MoO 2 /Ni 3 S 2 /NF electrocatalyst exhibits remarkable HER catalytic properties and durability with a low overpotential of 74.0 mV for achieving a current density of 10 mA cm −2 in 1.0 M KOH, as well as a long-term stability without obvious attenuation. Density functional theory (DFT) calculations reveal electron transfer at the interface domain reduces the energy barrier of the water dissociation step and optimizes H adsorption capability, thereby expediting HER kinetics in alkaline media . This work provides a viable strategy based on interfacial engineering for designing high-efficient HER electrocatalysts .
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Chang Wu,Yuyang Hou,Jicheng Jiang,Haipeng Guo,Hua-Kun Liu,Jun Chen,Jiazhao Wang
Li–O 2 batteries has been widely investigated for its ultra-high capacity as next generation batteries. Nevertheless, some problems like sluggish kinetic reaction and instability hugely impede the practical use of Li–O 2 batteries. In this work, Mo 2 C/MoO 2 @RGO heterostructures was fabricated by in-situ growth of Mo 2 C between MoO 2 and RGO during calcination and being employed as cathode to explore the synergistic effect in Li–O 2 batteries. As a result, Mo 2 C/MoO 2 @RGO exhibits good specific capacity with 2365 mAh g −1 , high round-trip efficiency (89% at first cycle) and improved cycling performance. Density functional theory calculations indicated that the Mo 2 C/MoO 2 @RGO heterostructures have better capability of oxygen adsorption than sole constituent (Mo 2 C@RGO or MoO 2 @RGO), which triggers the formation of film-like amorphous discharge products, leading to lower overpotential and stable performance. Our study reveals the important role of heterostructures in Li–O 2 batteries system and demonstrates a promising design strategy for heterostructured catalyst.
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
COMPOSITES PART B-ENGINEERING
·
2023
·
IF 13.1
Xiang Zhang,Zheng Xiang,Kai Yao,Xiao Wang,Hao jie Jiang,Jing li Wang,Wei Lu
Heterointerface engineering is now recognized as a powerful strategy to optimize the microwave absorption performance of dielectric materials through composition adjustment and structural design. Herein, a hydrangea-like N-doped Carbon/MoO 2 @SnS 2 (NC/MoO 2 @SnS 2 ) composite was successfully prepared by high-temperature pyrolysis and oil bath treatment. The surface of each NC/MoO 2 microsphere was vertically covered with interconnected SnS 2 nanosheets , forming a porous core-shell morphology. We found that the number of heterojunctions and the proportion of high-lossy phases played a decisive role in optimizing the electromagnetic parameters . By regulating the content of dielectric phases, the optimized NC/MoO 2 @SnS 2 (S3 sample) displayed a minimum reflection loss (RL min ) of −75.0 dB at an ultrathin thickness of 1.41 mm and a wide EAB of 4.2 GHz at 1.53 mm. The enhanced microwave absorption was mainly ascribed to multiple polarization relaxation, multi-interface reflection and good impedance matching characteristics produced by this semiconductor/carbon heterostructure with dual Schottky barriers . Therefore, this work provided a feasible strategy for making full use of heterointerface engineering to design ternary semiconductor/carbon heterostructures as high-performance dielectric MAMs.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2025
·Vol. 15
·期 5
·392
·
IF 4.3
Di Wu,Tianrong Yi,Yutao Hu,Jianxiong Xie,Yu Deng,Junqi He,Yuting Sun,Jidong Liu,Qiaoyan Hao,Wenjing Zhang
The morphology modulation of target crystals is important for understanding their growth mechanisms and potential applications. Herein, we report a convenient method for modulating the morphology of MoO2by controlling different growth temperatures. With an increase in growth temperature, the morphology of MoO2changes from a nanoribbon to a nanoflake. Various characterization methods, including optical microscopy, atomic force microscopy, (vertical and tilted) scanning electron microscopy, Raman spectroscopy, high-resolution transmission electron microscopy, and selected area electron diffraction, were performed to unveil the morphology modulation and lattice structure of MoO2. Both MoO2nanoribbons and nanoflakes display a standing-up growth mode on c-sapphire substrates, and their basal planes are MoO2(100). Further investigations into devices based on MoS2with Au/Ti/MoO2electrodes show the potential applications of MoO2in two-dimensional electrodes. These findings are helpful for the synthesis of MoO2with different morphologies and applications in the field of optoelectronic nanodevices.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS LETTERS
·
2023
·Vol. 122
·期 11
·
IF 4
Yang Dingbang,Jiang Junjie,Chen Jiaxin,Guo Xiao,Yang Xinhui,Zheng Xiaoming,Deng Chuyun,Xie Haipeng,Song Fei,Ouyang Fangping,Yuan Xiaoming,Chen Mingxing,Huang Han
Transition metal dichalcogenide based 2D/2D or 2D/3D van der Waals heterostructures exhibit superior properties for high-performance electronics, tunneling transistors, and catalysts. Here, we report on the fabrication of high quality 2D/3D MoS 2 /MoO 2 heterostructures with an atomic clean interface by one-step chemical vapor deposition. Optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy measurements reveal the high-quality of as-grown samples and the specific epitaxial relationship between MoS 2 and MoO 2 : MoS 2 [ 1 ¯ 1 ¯ 20]//MoO 2 [001] and MoS 2 [ 1 ¯ 100]//MoO 2 [201]. Photoluminescence and Kelvin probe force microscopy measurements combined with density functional theory calculations confirm the interfacial charge transfer from MoS 2 to the underlying MoO 2 . Furthermore, MoO 2 induced in-plane anisotropy in MoS 2 was revealed using angle-resolved polarized Raman and photoluminescence spectroscopy with anisotropic ratios of 1.27 (Raman) and 1.29 (photoluminescence), respectively, which is most possibly attributed to anisotropic interfacial charge interactions. Our findings provide an excellent platform for the investigation on interfacial effects. Moreover, the in-plane anisotropy in MoS 2 induced by MoO 2 has expanded the application of isotropic MoS 2 in the polarization-dependent fields.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Rundong Ma,Han Tian,Xu Yu,Xiangzhi Cui,Xinmei Hou,Shengli An
Hydrogen oxidation reaction (HOR) as the anode reaction in proton exchange membrane fuel cell, usually suffers from the high loading of platinum (Pt) and subsequent CO poisoning especially by using industrial crude hydrogen as fuel. In this work, we propose a directional electron transfer route from Pt to MoO 2- x in the macroporous structure to significantly enhance the HOR activity as well as the CO tolerance, which is constructed by interface engineering and defect strategy to anchor highly dispersed Pt nanoparticles onto the three-dimensional MoO 2- x -C framework. The optimized 2Pt-MoO 2- x -C with 1.02 wt% Pt demonstrates higher HOR peak current density (3.57 mA cm −2 ) and nearly 25 times higher mass activity than 20 wt% Pt/C. The excellent HOR performance is attributed to the synergistic effect between Pt and MoO 2- x species, in which the charge transfer from Pt to MoO 2- x improves H 2 adsorption ability of Pt and accelerates the activation of H 2 due to the reduced hydrogen binding energy of MoO 2- x caused by Pt-O construction, leading to the release of H* thereby the enhancement of HOR activity. The construction of three-dimensional macroporous structure enhances the HOR dynamics by promoting the conductivity, mass transfer and the exposure of active sites. Moreover, the formed Mo-OH in Pt-MoO 2- x -C can effectively react with CO species to remove the CO poisoning of Pt, endowing the excellent CO tolerance.
研究领域:
材料科学
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电化学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2024
·
IF 5.5
Shaodong Jing,Xiaolong Xiao,Zhen Liu,Mengyu Ma,Qian Li
Background In the treatment of organic wastewater, Fenton technology often produces iron sludge due to iron circulation obstruction, which inhibits the treatment efficiency and causes secondary pollution to the actual water. Methods In this study, MoO 2 was used as a cocatalyst to promote the effective cycling of Fe 2+ /Fe 3+ in the Fe 2+ /H 2 O 2 system, thus efficiently degrading total petroleum hydrocarbons (TPHs). The superiority of MoO 2 as co-catalyst was verified under different reaction conditions, and its mechanism was discussed. Findings The degradation rate of TPHs in the Fe 2+ /H 2 O 2 /MoO 2 system (0.069 min −1 ) was about 14 times that of Fe 2+ /H 2 O 2 system (0.005 min −1 ). Compared with the Fe 2+ /H 2 O 2 system, the Fe 2+ /H 2 O 2 /MoO 2 system not only had a wider pH adaptation range, but also could effectively remove TPHs under the interference of co-existing organic and inorganic anions. MoO 2 did not change the types of reactive species in Fenton system, but it enhanced the production of reactive oxygen species (ROS) by promoting the Fe 2+ /Fe 3+ cycling in the reaction system, and ·OH was the main reactive species of TPHs degradation.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Yue Yao,Enlai Hu,Zhiyu Wang,Yuanjing Cui,Guodong Qian
The rational design and synthesis of a highly efficient and cost-effective electrocatalyst for hydrogen evolution reaction (HER) are of great importance for the efficient generation of sustainable energy. Herein, amorphous/crystalline heterophase Ni–Mo–O/Cu (denoted as a/c Ni–Mo–O/Cu) was synthesized by a one-pot electrodeposition method. Thanks to the introduction of metallic Cu and the formation of amorphous Ni–Mo–O, the prepared electrocatalyst exhibits favorable conductivity and abundant active sites, which are favorable to the HER progress. Moreover, the interfaces consisting of Cu and Ni–Mo–O show electron transfers between these components, which might modify the absorption/desorption energy of H atoms, thus accelerating HER activity. As expected, the prepared a/c Ni–Mo–O/Cu possesses excellent HER performance, which affords an ultralow overpotential of 34.8 mV at 10 mA cm–2, comparable to that of 20 wt % Pt/C (35.0 mV), and remarkable stability under alkaline conditions.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS
·
2024
·Vol. 24
·期 13
·4320
·
IF 3.4
Min Zhang,Yi Han,Ting Liu,Hongguang Jia
High temperature represents a critical constraint in the development of gas sensors. Therefore, investigating gas sensors operating at room temperature holds significant practical importance. In this study, coal-based porous carbon (C-700) and coal-based C/MoO2nanohybrid materials were synthesized using a simple one-step vapor deposition and sintering method, and their gas-sensing performance was investigated. The gas-sensing performance for several VOC gases (phenol, ethyl acetate, ethanol, acetone, triethylamine, and toluene) and a 95% RH high-humidity environment were tested. The results indicated that the C/MoO2-450 sample sintered at 450 °C exhibited excellent specific selectivity towards acetone at room temperature, with a response value of 4153.09% and response/recovery times of 10.8 s and 2.9 s, respectively. Furthermore, the C/MoO2-450 sample also demonstrated good repeatability and long-term stability. The sensing mechanism of the synthesized materials was also explored. The superior gas-sensing performance can be attributed to the synergistic effect between the porous carbon and MoO2nanoparticles. Given the importance of enhancing the high-tech and high-value-added utilization of coal, this study provides a viable approach for utilizing coal-based carbon materials in detecting volatile organic compounds at room temperature.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Wei Cai,Jincheng Liu,Yijun Luo,Zewei Liao,Bingjie Li,Xiaoyan Xiang,Yanxiong Fang
The persistent hurdles of charge rapid recombination, inefficient use of light and utilization of sacrificial reagents have plagued the field of photocatalytic hydrogen evolution (PHE). In this research, tiny MoO 2 nanoparticles of 10 nm in diameter were prepared through a straightforward solvothermal approach with a specific ratio of oleylamine and oleic acid as stabilizers. The critical factor in the synthesis process was found to be the ratio of oleylamine to oleic acid. Moreover, a two-phase interface assembly method facilitated the uniform deposition of MoO 2 onto CdS nanorods. Due to the localized plasmonic-thermoelectric effect on the surface of MoO 2 along with its abundant oxygen vacancies , the composite catalyst exhibited outstanding photo-utilization efficiency and an abundance of active sites. The CdS-MoO 2 composite displayed a unique photochemical property in transforming lactic acid into pyruvic acid and generating hydrogen simultaneously. After exposure to artificial sunlight for 4 h, significant values of 4.7 and 3.7 mmol⋅g −1 ⋅h −1 were achieved for hydrogen production and pyruvic acid formation, respectively, exceeding CdS alone by 3.29 and 4.02-fold, while the selectivity of pyruvic acid was 95.68 %. Furthermore, the S-Scheme electron transport mechanism in the composites was elucidated using Electron Paramagnetic Resonance (EPR) spectroscopy, radical trapping experiments, energy band structure analysis, and the identification of critical intermediates in the process of selective oxidation. This work sheds light on the design and preparation of high-performance photocatalysts for biorefining coupled with efficient hydrogen evolution.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）