APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Qingqing Jiang,Sha Hu,Lin Wang,Zhengxi Huang,Hai-Jian Yang,Xiaole Han,Yongxiu Li,Chao Lv,Yu-Shi He,Tengfei Zhou,Juncheng Hu
Considering the suitable redox potential, low price, and abundant resource of potassium, potassium-ion batteries (PIBs) have attracted considerable attention as one of the alternatives to lithium-ion batteries (LIBs), however, the larger ionic radius of potassium ions makes it difficult to select suitable electrode materials. Herein, the MoSe 2 @MoO 2 heterojunction in which MoO 2 nanoparticles embedded on MoSe 2 nanosheets was synthesized by hydrothermal method and used as a novel anode material for PIBs. The electrochemical performance of the heterojunction was greatly improved as compared with the pure MoSe 2 and pure MoO 2 . At the current density of 500 mA g −1 after 100 cycle, the heterojunction electrode still maintains a capacity of 255 mA h g −1 and the coulomb efficiency is close to 100%. By introducing metallic MoO 2 can improve the electrical conductivity, furthermore, the MoSe 2 @MoO 2 heterostructures facilitate interfacial electron transport and built-in electric field makes the diffusion of K-ion easier. In addition, the well dispersed MoO 2 nanoparticles prevent the restacking of MoSe 2 nanosheets and maintain the structure stability during the charge/discharge process.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Qingliang Feng,Kaiyue Duan,Hong Xie,Muyin Xue,Yongling Du,Chunming Wang
Two dimensional (2D) transition metal dichalcogenides have attracted intense potential application in catalytic because of its fantastic physical and chemical properties. But, how the metal oxide affects the catalytic performance of transition metal dichalcogenides was not clear yet, which always exists as main byproduct in the synthesized process of hydrothermal method . Herein, we report synthesis of 2H-MoSe 2 nanoflower and 2H-MoSe 2 /α-MoO 3 heterostructure by hydrothermal method. The chemical composition , morphology and crystalline structure of nano-composite were characterized by field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The 2H-MoSe 2 nanoflower shows more positive onset overpotential around −150 mV and a current density of 32.5 mA cm −2 at −300 mV. The smaller Tafel slope of 2H-MoSe 2 nanoflower is around 69 mV dec −1 reveals the Volmer-Heyrovsky mechanism for HER. The results of linear scan voltammetry (LSV) curves demonstrated that both of them displayed good stability. This work demonstrated that the metal oxide can reduce the catalysis performance of transition metal dichalcogenides towards HER.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Pan Wang,Ji Qi,Xiaozhen Chen,Chuang Li,Tonghua Wang,Changhai Liang
Hydrogen evolution reaction (HER) is considered to be one of the most promising strategies to create hydrogen. Recently, searching high-efficient, stable, and earth-abundant electrocatalysts to replace precious metals for practical utilizations of HER is attracting more and more attentions. Herein, novel molybdenum carbide nanobelts containing Mo of high-valence state derived from MoO 3 -ethylenediamine inorganic/organic hybrid precursors are successfully synthesized via a facile one-pot pyrolysis method. The molybdenum carbide nanobelts are characterized using XRD , SEM, TEM and XPS . Moreover, the high-valence state Mo and their relative content in the molybdenum carbide nanobelts can be identified by XPS. The high-resolution XPS spectra of Mo 3d indicates in the molybdenum carbide nanobelts the proportion of high-valence state Mo in active Mo components is 51.3%. More importantly, the as-synthesized products exhibit excellent electrocatalytic activity for HER with a low onset overpotential of 50 mV and a small Tafel slope of 49.6 mV dec −1 in acidic medium (0.5 M H 2 SO 4 ). Besides, the catalysts require only overpotentials of 143 and 234 mV to achieve current densities of 10 and 220 mA cm −2 , respectively. Furthermore, they also exhibit good durability after 2000 cycles and constant current density test. Such excellent electrocatalytic HER performance can be ascribed to the high intrinsic activity of high-valence state Mo in Molybdenum Carbide. Synthesizing molybdenum carbide with high-valence state Mo electrocatalysts for HER will open up an exciting alternative avenue to acquire outstanding HER electrocatalytic activity.
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 ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Wenhui Zhu,Ali Reza Kamali
Thermal oxidation in air of molybdenum disulfide (MoS 2 ) into layer structured molybdenum trioxide (α-MoO 3 ) is investigated using a combination of thermal analysis, electron microscopy , Raman, X-ray diffraction and photoelectron spectroscopy . The phase evolutions occurred during the thermal process is characterized by the surface oxidation of MoS 2 , followed by the bulk oxidation to form α-MoO 3 and the formation of Mo 17 O 47 at higher temperatures. The single-phase MoO 3 formed at optimum temperature condition is found to possess crystalline defects and considerably greater values of Li-ion storage cycling and rate performances in comparison with samples prepared at alternative temperatures and also the initial MoS 2 . This sample (P-MoO 3 -820) exhibits a charge capacity of 628 mA h g −1 after 250 cycles (100 mA g −1 ) with a Li + diffusion coefficient of 2.3 × 10 -13 cm 2 s −1 , substantially greater than that of initial MoS 2 (8.1 × 10 −16 cm 2 s −1 ). The electrochemical performance of P-MoO 3 -820 in full-cell configuration against a commercial LiFePO 4 cathode is evaluated and a specific capacity of 100 mAh g −1 after 500 cycles is recorded. This article, for the first time, discusses the thermal oxidation in air of MoS 2 as a simple and relatively clean approach to fabricate defective crystalline MoO 3 with enhanced Li-ion storage kinetics.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Liangri Ying,Fei Liang,Zhen Huang,Jing Ding,Weilong Wang,Shule Liu,Jianfeng Lu
Solar-driven steam generation is widely considered as a promising strategy for desalination. However, before this technology can be practically implemented, certain challenges such as suboptimal steam generation rates and inevitable salt deposition need to be addressed. In this study, we propose a novel bilayer structure aerogel (MS-aerogel), which confines urchin-like MoS 2 /Mo 5 N 6 /C in a biomass gelatin substrate to achieve high-efficiency desalination in high concentration brine solutions. The urchin-like MoS 2 /Mo 5 N 6 /C that hybrid semiconductor MoS 2 , plasmonic Mo 5 N 6 and porous carbon performs superior light-to-heat conversion performance to its individual components. Additionally, under the collaborative action of hydrophilic groups and unique nanostructured surface, the MoS 2 /Mo 5 N 6 /C exhibits a notable reduction in interface evaporation enthalpy from 2405.8 to 1694.6 J g −1 . Taking into consideration the comprehensive thermal management performance, the self-floating MS-aerogel achieves an excellent evaporation rate of 1.89 kg m -2 h −1 under one sun irradiation. Furthermore, the vertically aligned vessels present in the MS-aerogel facilitate salt transportation, effectively preventing crystalline salt accumulation on the evaporator surface. Consequently, even after continuous 12 h desalination in 20 wt% brine, the MS-aerogel maintains an outstanding evaporation rate of 1.54 kg m -2 h −1 , surpassing most reported self-floating evaporators. This research offers a valuable reference for the design of high-efficiency and salt-resistant solar evaporators.
研究领域:
材料科学
·
能源工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2022
·
IF 7.72
Jin Huang,Jian Zhang,Tingting Luo,Ruxia Liu,QinQin Wei,Guoqiang Luo,Qiang Shen
Corrosion test of Mo in LiF-LiCl-LiBr salt with different SO 4 2 content have been studied. MoO 2 , Mo 3 S 4 and MoS 2 was formed after corrosion. The SO 4 2- will corrode the grain boundary of Mo and lead to the decomposition of large Mo grain. Moreover, the formation of different corrosion products will lead to significant changes in volume and destroy the stable oxide layer which could be protective. The Mo will be severely corroded in LiF-LiCl-LiBr molten salt with a higher content of SO 4 2- .
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
·
2021
·Vol. 45
·期 31
·14042-14049
·
IF 3.591
Yaoxia Yang,Xuqin An,Mi Kang,Fengyao Guo,Lan Zhang,Qingtao Wang,Dongfei Sun,Yuan Liao,Zhiwang Yang,Ziqiang Lei
The construction of excellently performing electrocatalysts for hydrogen evolution reaction (HER) with a low-cost and economical strategy is still struggling with an enormous challenge in electrochemical water splitting. In this work, a novel N-doped porous carbon substrate constructed heterojunction electrocatalyst (MoS2-MoP/NC) was fabricated by a simple and facile method. Based on the electronic interaction and synergistic effect between MoS2 and MoP phases, the fabricated MoS2-MoP/NC heterojunction catalyst exhibited excellent electrocatalytic ability. In addition, the N-doped porous carbon substrate had a good charge/mass-transfer ability, which could effectively facilitate electronic transmission or prevent the aggregation of MoS2-MoP nanosheets and improve the catalytic activity. The heterojunction catalyst significantly improved HER activity with a low overpotential of 83 and 103 mV at 10 mA cm−2 in a 1.0 M KOH and 0.5 M H2SO4 and Tafel slope of 59.38 and 59.20 mV dec−1 for HER, respectively. This work provides a simple, less expensive and efficient approach for constructing high-performance heterojunction catalysts for HER.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Peirong Chen,Hao Zhong,Liuzhang Ouyang,Haiwen Li
Interfacial engineering is an effective approach for regulating the electronic structure of molybdenum carbides and promoting the hydrogen evolution reaction (HER). However, the development of a facile, cost-effective, and scalable synthesis method is crucial for industrial applications. In this work, we developed a mechanochemical method for the preparation of a composite of MoO 2 /MoC with superior HER electrocatalytic performance in alkaline solutions. The MoO 2 /MoC composite can be easily formed by ball milling for 1 h at ambient conditions, and this process can be scaled up for large-scale industrialization. The composite construction leads to a redistribution of electrons around the interface, optimizing the adsorption energy and enhancing the HER performance beyond that of Pt/C catalysts. This strategy provides a new route for the simple and efficient preparation of high-activity electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Energy Storage Materials
·
2018
·
IF 0
Longlu Wang,Qingfeng Zhang,Jingyi Zhu,Xidong Duan,Zhi Xu,Yutang Liu,Hongguan Yang,Bingan Lu
Two-dimensional (2D) layered transition metal sulfide based materials are promising candidates for electrodes of lithium ion batteries (LIBs). As one of the representatives, molybdenum disulfide (MoS 2 ), exhibits additional reversible capacity beyond their theoretical value although the lithium storage mechanism is still poorly understood. In this report, we developed a highly conducting metallic phase 1T(octahedral)-MoS 2 based electrode with metal Mo atoms confined in “graphene nanoreactor” of abnormal lithium-storage sites, which delivered a high specific capacity of ~1800 mAh g −1 at 1 A g -1 , about 2.6 times of its intercalation reactions value. Contrary to previous reports, a new lithium-storage mechanism for the high and ever-increasing capacity was proposed. The theoretical calculations and experiments show that a major contribution to the extra capacity in MoS 2 anodes is due to Mo atoms accommodate with Li + . The Mo precipitates and their full contact with Li 2 S matrix enabled the reversible Mo→Li x Mo→Mo→1T-MoS 2 reaction during charging/discharging processes. Over prolonged cycling, per Mo atomic could accommodate six Li + ions. This new proposal could help to establish an accurate electrochemical reaction mechanism of MoS 2 LIBs, which may lead to inspiration on new methods to greatly improve the performance of the MoS 2 anode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Hu Sun,Jialu Xu,Jingdong Huang,Guanghui Li,Jun Luo,Mingjun Rao,Zhiwei Peng,Tao Jiang
A hetero-structured few-layer MoS 2 -coated MoO 2 (MoS 2 @MoO 2 ) has been fabricated and applied as an anode material for LIBs . The MoS 2 @MoO 2 was synthesized via two-step fire process: reducing MoO 3 vapor with H 2 for producing Mo powder, and oxidizing-sulfurizing Mo powder with SO 2 . With the aid of thermodynamic computations, it is found that Mo oxidation under SO 2 atmosphere produces limited amounts of S 2 vapor, which will locally sulfurize the particles nearby, resulting in finite and even sulfurization. The as-prepared MoS 2 @MoO 2 includes few-layer MoS 2 (about 3 nm thick) covering the surface, which serves a well-spreading and active material that synergizes with inner MoO 2 to boost the performance for LIBs. Thus, the MoS 2 @MoO 2 could deliver a high reversible specific capacity of 1263 mA h g −1 after 40 cycles at 0.1 A g −1 , and maintain a specific capacity of 1052 mA h g −1 after 150 cycles at 0.2 A g −1 . Even at 0.5 A g −1 , the specific capacity could still keep above 650 mA h g −1 for over 500 cycles. The new method for MoS 2 @MoO 2 synthesis is facile and effective, and may be extended to produce hybrids composed of other transition metal oxides and sulfides.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Sustainable Metallurgy
·
2025
·
IF 3.2
Mi Jiayu,Wang Zhenqiang,Qiu Yuqing,Chen Xingyu,Chen Ailiang,Liu Xuheng,Li Jiangtao,He Lihua,Sun Fenglong,Zhao Zhongwei
The leaching agents for molybdenum calcine are mainly acid and alkali solutions represented by ammonia water, which have poor selectivity for molybdenum and are not environmentally friendly. Therefore, a novel leaching agent which can avoid the aforementioned problems needs to be sought. Given that molybdenum in molybdenum calcine mainly exists in the form of molybdenum trioxide, this research investigated the dissolution behavior of molybdenum trioxide in sodium molybdate solution under different process conditions was studied, and the leaching of molybdenum calcine in sodium molybdate solution was preliminarily tested. The Raman characterization results of the dissolution system indicated that molybdenum trioxide and sodium molybdate with low polymerized states can form high polymerized molybdate through self-coordination reaction. The optimal dissolution conditions were 85 °C, pH 8.00, initial molybdenum concentration 26.78 g/L. Under the optimal conditions, the dissolution capacity of molybdenum trioxide in sodium molybdate can reach 2.460 g/g. The preliminary leaching test indicated that the sodium molybdate system had a high selectivity for molybdenum in molybdenum calcine, and the leaching ratio of molybdenum was 96.4%. This study confirmed the feasibility of sodium molybdate as a leaching agent for molybdenum calcine and laid a theoretical foundation for the leaching process of molybdenum calcine. Graphical
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Energy Storage Materials
·
2021
·
IF 17.789
Xiaowei Mu,Chao Xia,Bin Gao,Shuyi Guo,Xueping Zhang,Jianping He,Yonggang Wang,Hao Dong,Ping He,Haoshen Zhou
Rechargeable Li-O 2 batteries have captured increasing attention owing to their ultra-high theoretical specific energy. However, this promising system is confronted with the large overpotential, limited discharge capacity and low cyclic life. Herein, three two-dimensional (2D) molybdenum-based compounds of MoN, MoO 3 and MoS 2 are used as cathode catalysts in Li-O 2 batteries . The catalytic performance and electronic structures of these catalysts are compared comprehensively. Electrochemical test results reveal the superior battery performance of MoN cathodes, which deliver the highest specific discharge capacity of approximately 7400 mAh g − 1 and the lowest discharge/charge overpotential of 0.19/0.72 V. Density functional theory (DFT) calculations demonstrate the metallic property of MoN whereas MoO 3 and MoS 2 are poor conductive. Besides, interface properties between MoN and Li 2 O 2 products as well as reaction pathways of the Li-O 2 battery with MoN cathode are also investigated detailedly by DFT calculations, explaining the excellent catalytic properties of MoN at the atomic level. The present work provides intrinsic insights into designing high-performance cathode catalysts for Li-O 2 batteries with fine-tuned morphology and electronic characteristics.
研究领域:
材料科学
·
电化学
·
电池技术
·
催化
·
理论化学
✓ 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）