INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Xinxin Li,Suqin Ci,Jingchun Jia,Zhenhai Wen
The rational design of cost-effective and high-activity electrocatalyst for hydrogen evolution reaction (HER) is a crucial field of research for achieving the best way to promote “green energy”. Here, we develop a simple route to prepare nanohybrids of three-dimensional graphene loading MoO 2 Mo 2 C nanoparticles (MoO 2 Mo 2 C/G), which were characterized using X-ray diffractometer (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), demonstrating the MoO 2 Mo 2 C/G has unique features with high conductivity, robust structure, and high surface area. The as-developed MoO 2 Mo 2 C/G nanohybrid shows great potential to replace Pt-based electrocatalyst for hydrogen evolution reaction (HER) due to its cheapness, high catalytic activity and considerable stability.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Yong Zeng,Yingdi Dong,Xiongxing Zhang,Zhongbao Hua,Xiqing Wu,Wei Sun,Haisheng Han,Li Wang,Honghu Tang
In the flotation separation of Mo-Pb bulk concentrate and the purification process of Pb-containing molybdenite concentrate, depressants are typically added to depress galena or molybdenite, aiming to obtain high-quality flotation products. Previous studies have focused on the depression of galena. In this study, gallic acid (GA) was utilized as a molybdenite depressant during Mo-Pb flotation separation. Single mineral flotation experiments showed that pH notably influenced galena and molybdenite flotation with GA, particularly at pH 10, displaying the most substantial recovery difference. Mixed mineral flotation experiments revealed GA’s selective depression on molybdenite. At the optimal dosage of GA, the Mo recovery was reduced by 76.62 percentage points, while the Pb recovery remained unaffected. The depression and separation mechanisms of GA were investigated using contact angle, infrared spectroscopy, Zeta potential, inductively coupled plasma optical emission spectrometer (ICP-OES), X-ray photoelectron spectroscopy (XPS) analysis, first-principles calculations analysis, and interface interaction free energy calculations. The results indicate that GA treatment significantly reduces the hydrophobicity of molybdenite surfaces; however, it slightly enhances the hydrophobicity of galena surfaces. At pH 10, the primary species in GA solution is HGA 3- . It adsorbs on PbO species of the galena surface as Pb-GA complexes and tends to detach from the surface at high adsorption capacity, resulting in galena not being depressed by GA. Differently, GA adsorbs on the molybdenite surface through hydrophobic attraction force, rendering it hydrophilic. Additionally, after treatment with potassium butyl xanthate (PBX), the hydrophobicity of GA-treated galena is significantly enhanced, while the hydrophobicity of GA-treated molybdenite is not restored. This is because PBX can adsorb stably on GA-treated galena, but its adsorption on GA-treated molybdenite is hindered by the pre-adsorbed GA.
研究领域:
矿物加工工程
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2020
·Vol. 7
·期 3
·036201
·
IF 1.929
Hui Yu,Xinan Shi,Lijian Huang,Xiaojiao Kang,Daocheng Pan
A series of Eu3+ and Tb3+ co-doped CaMoO4/SrMoO4 luminescent thin films were prepared by a facile solution method, and they were annealed at 550 °C for 2 h. The luminescent properties of the thin films were studied, which involve the energy transfer from Tb3+ to Eu3+. The emission color can be changed from green to red, with increasing Eu3+ doping concentration in Tb3+-doped CaMoO4/SrMoO4 thin films. In addition, it was observed that the PL intensity of Eu3+ will enhance when Tb3+ ions are incorporated into Eu3+-doped CaMoO4/SrMoO4 thin films. The optical band gaps of the luminescent thin films are found to be in the range of 4.49 to 4.72 eV. These results revealed that Eu3+ and Tb3+ co-doped CaMoO4/SrMoO4 luminescent thin films have a significantly potential application in electroluminescent devices.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Jinyang Wu,Mingjun Jing,Tianjing Wu,Mingguang Yi,Yansong Bai,Wenhui Deng,Yirong Zhu,Yingchang Yang,Xianyou Wang
Mo-based heterostructures offer a new strategy to improve the electronics/ion transport and diffusion kinetics of the anode materials for sodium-ion batteries (SIBs). MoO 2 /MoS 2 hollow nanospheres have been successfully designed via in-situ ion exchange technology with the spherical coordination compound Mo-glycerates (MoG). The structural evolution processes of pure MoO 2 , MoO 2 /MoS 2 , and pure MoS 2 materials have been investigated, illustrating that the structure of the nanosphere can be maintained by introducing the S-Mo-S bond. Based on the high conductivity of MoO 2 , the layered structure of MoS 2 and the synergistic effect between components, as-obtained MoO 2 /MoS 2 hollow nanospheres display enhanced electrochemical kinetic behaviors for SIBs. The MoO 2 /MoS 2 hollow nanospheres achieve a rate performance with 72% capacity retention at a current of 3200 mA g −1 compared to 100 mA g −1 . The capacity can be restored to the initial capacity after a current returns to 100 mA g −1 , while the capacity fading of pure MoS 2 is up to 24%. Moreover, the MoO 2 /MoS 2 hollow nanospheres also exhibit cycling stability, maintaining a stable capacity of 455.4 mAh g −1 after 100 cycles at a current of 100 mA g −1 . In this work, the design strategy for the hollow composite structure provides insight into the preparation of energy storage materials.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 44
·期 2
·537-542
·
IF 3.069
Zhenyu Li,Fa Cao,Lei Wang,Zhiwu Chen,Xiaohong Ji
In this article, novel ternary MoS2/MoO3/TiO2 composite catalysts were developed. The photocatalytic performance of the ternary MoS2/MoO3/TiO2 composites was evaluated by photo-degradation of rhodamine B (RhB). It was found that the photocatalytic ability of the composites was strongly dependent on the mass ratio of MoS2–MoO3 to MoS2–MoO3–TiO2. The ternary composite catalyst with optimum composition showed a fast degradation rate (maximum ∼0.138 min−1), which could degrade over 95% of RhB solution (10 mg L−1) within 20 min under visible light (λ > 420 nm) irradiation. The possible photocatalytic mechanism was proposed based on the trapping photocatalytic experiment and band alignment of the composite. The synergistic effect of the strong absorption of the catalyst and the efficient separation of photogenerated electron–hole pairs by the novel ternary composite contributed to the enhanced photocatalytic activity.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Zhenlu Zhao,Ke Lu,Song Song
The advancement of stable and highly efficient non-noble metal-based bifunctional electrocatalysts represents a formidable challenge in the realm of overall water splitting technology. In this study, CoMoO 4 ||CoMoP-based nanocolumn arrays were designed and synthesized using Co-doped molybdophoxide polyoxometalate (PMo), which is grown in situ on nickel foam (NF). Co doping is employed to conduct appropriate electronic modulation of Mo, thereby enhancing the hydrogen evolution reaction (HER) performance. When used in oxygen evolution reaction (OER), surface reconstruction is induced by electrochemical activation, in which the stable structure of PMo serves to balance the newly formed active OER amorphous metal hydroxy-oxide (hydroxide) compounds. The sample exhibits a HER overpotential of 96 mV and an OER overpotential of 234 mV at a current density of 10 mA·cm −2 . When utilizing CoMoO 4 ||CoMoP-based catalyst as both the cathode and anode assembly, the overall water splitting system can provide a current density of 10 mA·cm −2 at a driving voltage of merely 1.509 V, and can achieve long-term stability over 100 h, outperforming most previously reported bifunctional electrocatalysts. This work offers a promising approach for constructing high-performance bifunctional electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE FORUM
·
2018
·
IF 0
De Zhi Wang,Yu Qing Zhang,Bo Hua Duan
In this work, Molybdenum trioxide and conventional copper particles were used as precursors, reduced in hydrogen atmosphere. Then Cu@Mo Powders were successfully synthesized. Effects of reduction temperature on the microstructure of the composite powders and the performance of the intermediate product (molybdenum dioxide) were investigated. Results show that 700°C is the optimal reduction temperature, because Mo is reduced from its oxide and forms a coating layer on the surface of copper particles tightly without serious crack. Mo-20wt.% Cu composite powders where Cu is coated uniformly with continuous molybdenum layer are successfully obtained by co-reduction method.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Lijun Zhang,Zhiliang Jin,Noritatsu Tsubaki
As a crucial part of artificial photosynthesis, the design of the catalyst is important essential. Among them, the interface engineering between semiconductors and the construction of surface-active sites play a vital role in generating and transporting light-excited electrons, which can ultimately accelerate water decomposition. Therefore, the MoS 2 @MoO 3 step (S)-scheme heterojunction photocatalyst was prepared by in-situ partial sulfidation. The excellent interface engineering of MoS 2 @MoO 3 nanomaterials achieves a high surface reaction rate. The in-situ vulcanization strategy gradually corrodes from the outside to the inside. The introduction of sulfur atoms can replace oxygen atoms to build a sulfur-rich surface and generate molybdenum sulfide. The amount of thioacetamide is adjusted to control vulcanization and optimizing the experimental conditions, the best hydrogen production rate is 12416.8 µmol h −1 g −1 . An in-situ irradiation XPS experiments and DFT calculations provide a deeper understanding of the S-scheme electron transport mechanism in MoS 2 @MoO 3 . MoS 2 @MoO 3 interface interaction has penetrating electron channels and a strong interface interaction force, which effectively promotes the charge transfer between interfaces. This gradual surface vulcanization strategy provides new ideas for introducing synergistic surface-active sites and optimizing interface engineering photocatalyst projects.
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
ACS Applied Nano Materials
·
2022
·
IF 6.14
Zhifeng He,Yuchen Jiang,Xin Cui,Zeyi Liu,Xin Meng,Jiafeng Wan,Fangwei Ma
Recently, molybdenum (Mo)-based catalysts have been proved to be effective NRR catalysts due to the high affinity of nitrogen to Mo. The design of a heterostructure and the introduction of defects, such as vacancies and heteroatom doping, are effective means to regulate the microstructure of catalysts and further improve their electrocatalytic N2 into NH3 performance. In this paper, VS-Fe-doped 1T/2H mixed-phase MoS2/C (VS means sulfur vacancies) heterostructure sphere-like nanoflowers with rich sulfur vacancies are prepared through a pectin-assisted hydrothermal reaction, followed by calcination and treatment with NaBH4 solution. VS-Fe-MoS2/C exhibits good electrocatalytic NRR performance with a high ammonia yield rate of 17.8 ± 0.7 μg h–1 mg–1 at −0.5 V versus reversible hydrogen electrode (vs RHE) and a Faraday efficiency (FE) of 9.2% at −0.3 V (vs RHE) under ambient conditions. Introducing sulfur vacancies, iron doping, and preparing 2H-phase MoS2 have greatly improved the performance of electrocatalytic nitrogen reduction to ammonia.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Dong Chen,Donggang Tao,Xin Ren,Fanjue Wen,Ting Li,Zhongxue Chen,Yuliang Cao,Fei Xu
Rechargeable magnesium batteries (RMBs) are a promising large-scale energy-storage technology with low cost and high reliability. However, developing high-performance cathode materials remains the most prominent obstacle because of the insufficient magnesium-storage active sites and unfavorable magnesium cation transport paths, as well as the strong interaction between the cathode material and the bivalent magnesium cation. Herein, ammonium tetrathiomolybdate is demonstrated to be a high-performance RMB cathode material. Ammonium tetrathiomolybdate exhibits a high capacity of 333 mAh g–1 at 50 mA g–1 and a good rate performance of 129 mAh g–1 at 5.0 A g–1 (∼15 C). An amorphous structure with plenty of efficient magnesium-storage active sites and open magnesium transport paths is in situ formed during the first cycle via ammonium extraction. The covalent-like bond between the molybdenum and sulfur delocalizes the negative charge, weakening the interaction with the bivalent magnesium cation and accelerating the kinetics. The covalent-like molybdenum–sulfur bond also promotes the simultaneous redox of molybdenum and sulfur, leading to a high specific capacity. The present work introduces a high-capacity and high-power RMB cathode material, elucidates the origin of the high performance, and provides insights for the design and optimization of RMB cathode materials.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Zhihua Li,Jin Lu,Shengxi Wu,Guiqing Zhang,Wenjuan Guan,Li Zeng,Qinggang Li,Zuoying Cao
Complete separation of tungsten from molybdenum has long been a technical bottleneck in the metallurgy of molybdenum because no theoretical basis exists for the complexation and extraction mechanism of tungsten and molybdenum from aqueous solution. To completely separate tungsten from ammonium molybdate, the speciation and equilibria of compounds in H+–WO42–, H+–MoO42–, and H+–MoO42––WO42– aqueous systems were systematically investigated. With decreasing pH, the stability of polymerized tungsten species in H+–MoO42––WO42– decreased in the following order: MoW6O246– > Mo2W5O246– > Mo3W4O246– > Mo4W3O246– > Mo5W2O246– > Mo6WO246–, and as the W(VI) concentration decreased, low-molecular-weight species increasingly dominated the W(VI) and Mo(VI) polymerization products. The extraction characteristics of tungsten and molybdenum with primary N1923 were consistent with their polymerization behaviors. Methods based on the thermodynamic theory and the aforementioned extraction mechanism were used to completely separate W(VI) from ammonium molybdate solution containing different grades of W(VI) (trace to macro). Ammonium molybdate solution with a 2.25 × 10–7 W/Mo mass ratio met the purity requirement for ultra-high-purity ammonium molybdate (99.999%, 5N) and further molybdenum products. During extraction, the equilibrium pH was controlled by extractant acidification using inexpensive mineral acids. The proposed process is cheap and sustainable and has a broad spectrum and high efficiency; these advantages are expected to provide economic and environmental benefits.
研究领域:
冶金学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Yao-Jen Tu,Ting-Shan Chan,Hao-Wei Tu,Shan-Li Wang,Chen-Feng You,Chien-Kuei Chang
An efficient method for removing and recovering molybdenum (Mo) from water was developed by using ZnFe 2 O 4 nanoparticles . The Mo adsorption displayed a nonlinear isotherm that fitted well with the Langmuir isotherm , showing limited adsorption sites on the surface of ZnFe 2 O 4 . The adsorption of Mo(VI) was dependent on solution pH. With increasing pH, the build-up of negative charges of both adsorbent and adsorbate led to enhanced electric repulsion between them. The K -edge XANES spectra for the adsorbents collected after Mo adsorption revealed that Mo(VI) was the predominant oxidation state sorbed on ZnFe 2 O 4 , indicating that the reduction of Mo(VI) did not occur on ZnFe 2 O 4 . The different peak positions of k-space and R-space shown in K-edge EXAFS spectra demonstrated that the adsorbed Mo could be bound on the surface or be slipped in the vacancy position of the ZnFe 2 O 4 crystal. Importantly, Mo could be efficiently adsorbed from photoelectric industrial wastewater and these adsorbed Mo anions were rapidly replaced by OH − ions, implying the potential for Mo removing and recovering in industrial wastewater.
研究领域:
环境科学
·
纳米材料
·
水处理
·
吸附化学
·
环境工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）