PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
·
2021
·Vol. 218
·期 22
·2100377
·
IF 1.981
Pan Liu,Sumin Wang,Yufei Quan,Zhiruo Shen,Qiguan Wang
2D composited nanosheets of Mo 2 C/CoMoS 4 are synthesized by a hydrothermal approach to obtain a bifunctional water-splitting electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in aqueous alkaline solution. Due to the richened defects formed on the 2D catalyst, the as-derived Mo 2 C/CoMoS 4 exhibits high activity. At 10 mA cm −2 , the HER and OER overpotentials of the 2D Mo 2 C/CoMoS 4 nanosheets are just 117 and 250 mV, respectively, with the corresponding Tafel slope of 90 and 75 mV dec −1 , near to the commercial Pt/C and IrO 2 . X-ray photoelectron spectroscopy proves the strong interactions between Mo 2 C and CoMoS 4 and the Raman analysis certifies the presence of richened defects in Mo 2 C/CoMoS 4 . Moreover, the Mo 2 C/CoMoS 4 possesses a long-term catalytic stability, showing potential application in the water splitting.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2022
·
IF 3.806
Sen Jin,Yitong Guo,Junkai Wang,Libo Wang,Qianku Hu,Aiguo Zhou
In this paper, the CO 2 adsorption behaviors of Mo 2 C MXene were explored for the first time. Two-dimensional (2D) Mo 2 C MXene samples were prepared by hydrothermal etching in four different solutions (LiF, NaF, KF or NH 4 F with HCl). The sample made by LiF + HCl etching exhibited the highest capacity of 3.66 mmol g −1 , which is consistent with theoretical calculation that Mo 2 CO 2 decorated by Li has stronger interaction with CO 2 than those of Na and K. Although Mo 2 C MXene has low specific surface area (SSA, 4.9–8.9 m 2 g −1 ) as compared with those of Ti 3 C 2 (21 m 2 g −1 ) and V 2 C (9 m 2 g −1 ) MXenes, Mo 2 C MXene possesses better performance on CO 2 capture than Ti 3 C 2 (1.33 mmol g −1 ) and V 2 C (0.52 mmol g −1 ) MXenes at 4 MPa. This is because the CO 2 adsorption of Mo 2 C MXene is mainly physical absorption formed by the capillary condensation in mixed pores (micropores and mesopores) and slitlike pores between two Mo 2 C MXene flakes. Besides, the CO 2 adsorption on the surface of Mo 2 C MXene with functional groups (O or F) shows a current of chemisorption feature. This work indicates that Mo 2 C MXene is a promising candidate for CO 2 capture and storage material.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
He-Qiang Chang,Guo-Hua Zhang,Kuo-Chih Chou
Electrochemical water splitting is considered a sustainable route for the hydrogen industry. In this work, Mo 2 C/MoC heterostructure supported on N -doped carbon (Mo 2 C/MoC@NC) was prepared via a carbonization strategy. For the product (Mo 2 C/MoC@NC-1-2) fabricated with a g-C 3 N 4 / ammonium molybdate tetrahydrate molar ratio of 1:2 at 700 °C under 10%CH 4 /H 2 atmosphere, a high stability and good HER activity with a η 10 of 113 mV in 1M KOH were achieved. To further enhance the catalytic performance of the synthesized Mo 2 C/MoC@NC, the phosphating strategy was proposed for the preparation of Mo 2 C/MoC/MoP heterostructure supported on N-doped carbon (Mo 2 C/MoC/MoP@NC). When the precursor Mo 2 C/MoC@NC-1-2 was phosphated at 650 °C with a heating rate of 5 °C min −1 and kept for 0 min, the as-synthesized Mo 2 C/MoC/MoP@NC-650-0 exhibits good HER catalytic activity with a pretty low η 10 of 78 mV, a j 0 of 0.398 mA cm −2 , and a Tafel slope of 52 mV dec −1 in 1M KOH. This good activity of HER can be ascribed to the N-doped carbon as substrate and the construction of transition metal-based heterostructures.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 11
·e5208
·
IF 3.259
Baowei Wang,Chengyu Wang,Wenxian Yu
Mo 2 C/Al 2 O 3 catalyst was prepared by the impregnation method with urotropine and ammonium paramolybdate. The catalytic effect of Mo 2 C as a typical transition-metal carbide in sulfur-resistant methanation was studied. The catalysts prepared were characterized by N 2 adsorption–desorption, X-ray diffraction, transmission electron microscopy, H 2 -temperature-programmed reduction, and Raman spectra, with the results confirming the formation of β-molybdenum carbide on the surface of the catalysts. Studies on catalysts with different loading doses indicate that the optimal loading of Mo 2 C/Al 2 O 3 is about 15 wt.%, which enables CO conversion rate of up to 47%, with methane selectivity of up to 53%. This work further explored the effect of different concentrations of H 2 S in the raw gas on the performance of the catalyst, with the results showing that high concentration of H 2 S (>1500 ppm) can lead to sulfuration of active species on the catalyst, while resulting in a decrease in the catalytic activity.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yahui Wang,Xuandong Li,Xijiang Han,Ping Xu,Liru Cui,Honghong Zhao,Dawei Liu,Fengyuan Wang,Yunchen Du
Transition metal carbides with good chemical stability and moderate dielectric constants are becoming popular electromagnetic (EM) absorption materials. In this work, Mo 2 C/Co/C composites, a ternary loss system (conductivity loss, polarization loss, and magnetic loss) for EM absorption, have been successfully fabricated by rationally regulating the growth of ZIF-67 on the surface of MoO 3 nanorods and subsequent pyrolysis process. The chemical compositions of Mo 2 C/Co/C composites indeed play a dominant role in tailoring their EM functions. It is revealed that conductivity loss, polarization loss, and magnetic loss are together responsible for the attenuation of EM energy. Although the involvement of Mo 2 C nanoparticles weakens magnetic loss capability to some extent, there will be a positive reinforcement in conductivity loss through the synergistic effects among different components. In addition, Mo 2 C nanoparticles can further provide considerable dipole orientation polarization and interfacial polarization. Among these ternary composite, MCC-50 with 30.9% of carbon, 53.6% of Mo 2 C, and 15.5% of Co, exhibits the best EM absorption performance, whose reflection loss intensity and qualified response bandwidth are superior to those of most carbide-based composites in previous studies. These results suggest that the rational integration of components with different loss mechanisms will be an effective pathway to enhance EM absorption.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Carbon Letters
·
2019
·Vol. 29
·期 3
·225-232
·
IF 1.807
Reddy Sathish,Song Li,Kang Lixing,Feng Quinliang,Du Ran,Zhang Jin,He Liumin,Seeram Ramakrishna
Highly active, stable and low-cost noble metal-free electrocatalysts are essential for production of hydrogen. However, preparation of such catalysts is still highly challenging so far. In this work, the Mo 2 C–carbon nanomaterials have been prepared by controlled thermal technique. By controlling concentration of the reactants in the experimental condition, the Mo 2 C–carbon nanomaterials have been fabricated, which leads to decreases in contact resistance b/w Mo 2 C–carbon nanomaterials and graphitic carbon atoms. As a result, the Mo 2 C–carbon nanomaterial electrode shows remarkable activity for hydrogen evolution reactions with a small onset overpotential of 95 mV, a Tafel slope of 62 mV dec −1 , an high exchange current density of 0.32 mA cm −2 , good stability during long-term 1000 cycles and exhibits long-term durability for several days. This study opens a new method for the preparation of highly active non-noble electrode for production of hydrogen from water splitting.
研究领域:
材料科学
·
能源化学
·
电催化
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Shuaipeng Wang,Shengli Zhu,Zhenduo Cui,Zhaoyang Li,Shuilin Wu,Wence Xu,Zhonghui Gao,Yanqin Liang,Hui Jiang
The quest for a cost-effective, high-performance catalyst for hydrogen production from electrolyzed water across a broad pH range holds immense importance. B, N co-doped Mo2C was first synthesized via microwave plasma chemical vapor deposition (MPCVD) for efficient hydrogen production from electrolyzed water. The B, N-Mo2C catalyst demonstrates a requirement of 81 mV in 1.0 M KOH to achieve a current density of 10 mA cm−2. Density functional theory (DFT) calculations revealed that B, N co-doping optimizes the charge transfer between H* and Mo2C, diminishes the excessive hydrogen binding energy of Mo2C, and supports effective and stable hydrogen evolution reaction (HER) conduction in diverse settings. This doping strategy offers a systematic design approach for designing highly active noble-metal-free HER catalysts.
研究领域:
材料科学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2018
·
IF 0
Yahui Wang,Chaolong Li,Xijiang Han,Dawei Liu,Honghong Zhao,Zhennan Li,Ping Xu,Yunchen Du
Carbides/carbon composites are becoming a new kind of microwave absorption (MA) materials with great potential in chemical stability and light weight, as well as enhanced performance. Herein, we design a series of Mo2C/C composites through a simple pyrolysis of Mo-substituted ZIF-8 (Mo/ZIF-8). It is found that the transformation of zeolitic imidazolate frameworks into carbon polyhedrons is accompanied by the in situ formation of ultrasmall Mo2C nanoparticles (Mo2C NPs) less than 5.0 nm. The molar ratio of 2-methylimidazole to molybdic acid (MIM/Mo) presents a significant effect on the relative content of Mo2C NPs but not on their average size. The uniform distribution of Mo2C NPs in carbon polyhedrons overcomes the poor chemical homogeneity in conventional carbides/carbon composites. More importantly, Mo2C NPs modulate the dielectric loss of these composites effectively. On one hand, they moderately weaken the contribution from conductivity loss and dipole orientation polarization; on the other hand, they create considerable interfacial polarization. As a result, these Mo2C/C composites display much better impedance matching than individual carbon polyhedrons. When the MIM/Mo ratio reaches 6.0, the optimized composite, S-Mo2C/C-6.0, displays good MA performance in the frequency range of 2.0–18.0 GHz, including powerful reflection loss and broad qualified bandwidth. Its performance is actually superior to those conventional carbides/carbon composites in previous studies, demonstrating that Mo2C/C composite from this novel strategy may be a promising candidate for high-performance MA materials in the future.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Xinyu Hu,Yongmei Wang,Liangliang Zhang,Man Xu,Jianfa Zhang,Wei Dong
Salecan, a water-soluble extracellular β-glucan, has emerged as a promising candidate for preparing hydrogel biomaterials recently. Herein, photo cross linked composite hydrogels, composed by salecan/poly ( N-tert -butylacrylamide-co-acrylamide) network andα-Mo 2 C nanoparticles were prepared by ultraviolet (UV) light, using Irgacue 2959 as photo initiator. The XRD and EDX analysis illustrated the presence of embeddedα-Mo 2 C nanoparticles throughout the hydrogel matrix. Compression tests and thermal analysis revealed that the incorporation of α-Mo 2 C nanoparticles enhanced mechanical strength and thermal stability due to the structural reinforcement of the composite hydrogels. Moreover, the change of salecan content provided a mean to tailor both the swelling property and morphology of the composite hydrogels. Encapsulation of L929 and 3T3-L1 cells and the following viability test showed the excellent cell-compatibility of these hydrogels. Taken together, these studies support the use of photo crosslinked composite hydrogels as tunable biomaterials for cell adhesion.
研究领域:
生物材料学
·
组织工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Kejing Wu,Junbo Wang,Yingming Zhu,Xueting Wang,Chunyan Yang,Yingying Liu,Changjun Liu,Houfang Lu,Bin Liang,Yongdan Li
The β-Mo2C on different carbon supports was prepared conveniently via direct H2 reduction or self-reduction for catalytic conversion of Kraft lignin into aromatic hydrocarbons, aromatic alcohols, and aromatic aldehydes. The β-Mo2C on macroporous carbon (MC) with large pore size exhibits the highest activity with aromatic yield of 0.543 g/g Kraft lignin at 280 °C for 3 h, resulting from the accessibility of lignin fragments to β-Mo2C. Mo, MoO2, and MoO3 possess relatively low activity. Higher calcination temperature is required to obtain β-Mo2C over graphite (Gr) support than MC and activated carbon (AC), and small grain size of Gr-supported catalysts is beneficial for high activity. The β-Mo2C on AC exhibits the highest selectivity to aromatic hydrocarbons, which are attributed to highly dispersed β-Mo2C in micropores.
研究领域:
催化化学
·
材料科学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2024
·
IF 15.7
Yu-Shuai Xu,Hong-Hui Wang,Qi-Yuan Li,Shi-Nan Zhang,Si-Yuan Xia,Dong Xu,Wei-Wei Lei,Jie-Sheng Chen,Xin-Hao Li
The development of two-dimensional heterogeneous catalysts with highly exposed active site areas for heterogeneous catalytic systems is highly promising for achieving the green transformation of small molecules. 2D transition metal carbides (TMCs) show great promise for catalysis and carbon capture but suffer from heavy aggregation and autooxidation. Mass transfer barrier is also a standard problem of lamellar TMCs caused by slight aggregation of layers. Here, we successfully developed a method to prepare “ladder-like” heterojunctions of Mo 2 C layers confined inside nitrogen-rich carbon sheaths (2D-Mo 2 C@NC) via an effective oxygen-diffusion etching strategy, acting as efficient catalysts for CO 2 fixation. The enhanced electron enrichment of the as-integrated 2D-Mo 2 C subunits induced by the Schottky barrier could further keep the exposed Mo 2 C surface from possible autooxidation and aggregation confronted by conventional 2D TMCs. The experimental results and density functional theory (DFT) calculation further demonstrate that electron-rich Mo 2 C could boost the adsorption and activation of CO 2 for universal carbonylation of various diamines, providing a turnover frequency value (TOF) of 10.2 h −1 to produce benzimidazolone, which is 5.2 times of that of the state-of-the-art catalyst in the literature under even critical conditions.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Li Luo,Dekang Li,Yuying Dang,Wei Wang,Guangsuo Yu,Jin Li,Baojun Ma
A non-noble metal cocatalyst with capacitance is cost-effective and has excellent photocatalytic H2 evolution performance for water splitting. But the intrinsic action of capacitance is unclear. Here, by controlling the capacitance of Mo2C, we reported a volcanic curve relationship between the photocatalytic activity of Mo2C/CdS and the capacitance of Mo2C. At the middle capacitance of 18.95 F/g of Mo2C-a4, Mo2C-a4/CdS exhibits the best H2 evolution activity of 5560 μmol/g/h. When Pt is introduced on the surface of Mo2C, the photocatalytic activity of (Pt/Mo2C-a4)/CdS is further enhanced to 8090 μmol/g/h. Comparing the activities between (Pt/Mo2C)/CdS and Mo2C/CdS with the capacitance of Mo2C, the activity ratio and difference values increase and finally reach a plateau with the increasing capacitance. Electrochemical and photoelectrochemical studies demonstrate that the capacitance of Mo2C has dual opposite effects (positive and negative) in photocatalytic reactions. The capacitance can capture electrons and store them, thereby enhancing the separation efficiency of photoexcited carriers of CdS. However, overlarge capacitance constrains the stored electrons and prevents them from releasing, thus decreasing the cocatalytic efficiency, which can be resolved in some degree by introducing some Pt on Mo2C. This work elucidates the dual effects of capacitance and puts forward the concept of capacitance catalysis.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）