ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Xiaoxiao Liu,Lei Zhang,Xiwei Lan,Xianluo Hu
Cost-effective Mo 2 C nanocrystals homogeneously distributed in interconnected mesoporous carbon nanofibers are prepared through an electrospinning route combined with a subsequent pyrolysis process . The crystal phases of the Mo 2 C nanocrystals are controllable and their phase-dependent electrocatalytic activities for the hydrogen evolution reaction (HER) are explored. The nanocomposite catalyst made of the hexagonal-phase Mo 2 C nanocrystals in carbon nanofibers exhibits outstanding electrocatalytic kinetics and high activities for the HER in both acidic and basic media. It is found that the overpotentials are 160 mV in 0.5 M H 2 SO 4 and 92 mV in 1 M KOH at a current density of 10 mA cm −2 . The Tafel slopes of 66 mV dec −1 in 0.5 M H 2 SO 4 and 63 mV dec −1 in 1 M KOH are achieved. Also, the as-obtained Mo 2 C/C electrocatalyst shows long-term durability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHINESE PHYSICS LETTERS
·
2024
·
IF 3.5
Longfu Li,Lei Shi,Lingyong Zeng,Kuan Li,Peifeng Yu,Kangwang Wang,Chao Zhang,Rui Chen,Zaichen Xiang,Yunwei Zhang,Huixia Luo
Chemical doping is a critical factor in the development of new superconductors or optimizing the superconducting transition temperature (Tc) of the parent superconducting materials. Herein, a new simple urea approach is developed to synthesize the N-doped α-Mo2C. Benefiting from the simple urea method, a broad superconducting dome is found in the Mo2C1-xNx (0 ≤ x ≤ 0.49) compositions. XRD results show that the structure of α-Mo2C remains unchanged and that there is a variation of lattice parameters with nitrogen doping. Resistivity, magnetic susceptibility, and heat capacity measurement results confirm that the superconducting transition temperature (Tc) was strongly increased from 2.68 K (x = 0) to 7.05 K (x = 0.49). First-principles calculations and our analysis indicate that increasing nitrogen doping leads to a rise in the density of states at the Fermi level and doping-induced phonon softening, which enhances electron-phonon coupling. This results in an increase in Tc and a sharp rise in the upper critical field. Our findings provide a promising strategy for fabricating transition metal carbonitrides and provide a material platform for further study of the superconductivity of transition metal carbides.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Long Zou,Yan Qiao,Shuang Gu,Yunhong Huang,Canyu Zhong,Zhong-er Long
The development of low-cost, scalable and realistic electrodes with robust catalytic activity and stability remains a great challenge for large-scale hydrogen production from electrochemical water splitting. Herein, we firstly reported a 3D self-supported porous hydrogen evolution cathode constructed by in-situ growth of nano-porous molybdenum carbide (Mo 2 C) nanoflakes on a commercial graphite felt (GF) through a facile electrostatic self-assembly followed by high-temperature carburization approach. Owing to a synergistic effect from high activity of nano-porous Mo 2 C and rich macroporous architecture of GF for fast diffusion of electrolyte and generated hydrogen bubbles, the 3D Mo 2 C@GF hybrid electrode only needs a low overpotential of 124 and 129 mV to deliver a cathodic current density of 10 mA cm −2 in 0.5 M H 2 SO 4 and 1 M KOH solution, respectively. Particularly, the strong incorporation of nano-Mo 2 C onto graphite fibers promotes interfacial electron transfer and enables superior stability and durability in both acidic and basic electrolyte. This work provides a proof of concept and design rules for developing truly workable electrodes with promising potential in practical hydrogen evolution.
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
·
2022
·
IF 6.371
Hao Song,Siguang Guo,Xuming Zhang,Yixuan Yang,Biao Gao,Yuancheng Pi,Chaoran Pi,Paul K. Chu,Kaifu Huo
The development of high active and cost-effective transition metal based catalysts as alternatives to Pt-based electrocatalysts for pH-universal hydrogen evolution reaction (HER) is highly desirable. Herein, we proposed a novel strategy to construct Mo 2 N uniformly embedded Mo 2 C nanobelt arrays electrocatalyst on N doped carbon framework (Mo 2 N-Mo 2 C/NC NBAs) by nitridation of MoO x /C hybrid precursors and subsequent annealing. The effect of N content towards the composition ratio of Mo 2 N to Mo 2 C and the structural evolution were studied. The in-situ formed Mo 2 N reduces the sintering of Mo 2 C phase and creates amounts of compact Mo 2 N-Mo 2 C interfaces and mesopores. Because of these high active interfaces, mesopores structure and self-supported architecture, the resultant Mo 2 N-Mo 2 C/NC catalyst exhibits remarkable HER performance and durability over a wide pH range, as exemplified by a small overpotentials of 75, 93, and 114 mV at 10 mA cm −2 , and Tafel slopes of 43, 58, and 62 mV dec −1 in the alkaline, neutral and acidic media. The results reveal a new avenue to design highly efficient electrocatalysts with tailored hetero/microstructures, which could be extended to fabricate other high-performance electrocatalyst and electrode materials for electrochemical energy conversion.
研究领域:
材料科学
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电化学
·
能源转换
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yujie Bao,Ting Chen,Zhiliang Zhu,Hua Zhang,Yanling Qiu,Daqiang Yin
Compared with generally reported Mo 4+ /Mo 6+ redox cycle, the exposed Mo 2+ active sites of Mo-based materials may have a superior potential to effectively activate PMS . However, Mo 2+ -involved materials as efficient catalysts in sulfate radical-based advanced oxidation processes (SR-AOPs) has rarely been researched. In this work, a spherical Mo 2 C-loaded carbon material, Mo 2 C/C, was prepared for the first time by hydrothermal-calcination method directly used as peroxymonosulfate (PMS) activator towards carbamazepine (CBZ) degradation. The results showed that the Mo 2 C/C could effectively remove nearly 100% CBZ (5 mg·L −1 ) in the presence of 0.75 mM PMS within 75 min under the optimal conditions. It was attributed to the reductive Mo 2+ , as active sites, benefits to absorb PMS on the surface to trigger electron transmission, and the defective carbon structures accelerate the activation of PMS. Consequently, the efficient Mo 2+ /Mo 4+ /Mo 6+ electron transfer was achieved, resulting in excellent catalysis. A series of reactive species including SO 4 − , OH and 1 O 2 species participated in CBZ oxidation degradation. Derived from the superior stability and reusability of Mo 2 C/C, the removal rate of CBZ still maintained above 80% even after five consecutive cycles, which is expected to be applied in the wastewater treatment including pharmaceuticals in the future.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 6
·4589-4600
·
IF 2.993
Tan Jiabin,He Xiaobo,Yin Fengxiang,Liang Xin,Chen Biaohua,Li Guoru,Yin Huaqiang
In this study, a β-Mo 2 C/N, P-co-doped carbon (NPC) catalyst with a porous structure of β-Mo 2 C nanoparticles loading on NPC matrix was prepared by vacuum-rotary evaporation and followed by a facile pyrolysis process for hydrogen evolution reaction (HER). The porous structure is beneficial for exposing more active sites and the mass transfer during the HER. In addition, the carbon matrixes with the highly doped N and P heteroatoms also provide their positive contributions to its high catalytic activity for HER. Owing to the advantages mentioned above, the optimized catalyst shows a small overpotential of 181 mV for driving a cathodic current density of 10 mA cm −2 , a low Tafel slope of 65.3 mV dec −1 and a high exchange current density of 1.5 × 10 −2 mA cm −2 during HER processes in acid electrolyte. The excellent performance of the β-Mo 2 C/NPC makes it a great potential candidate as the HER electrocatalyst.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2024
·
IF 2.3
Chen Yonghui,Zhao Jiafu,Song Mingzhu,Luo Shaojuan,Xie Shaoqu,Yan Kai
The development of safe, low-cost and highly active non-precious metal electrocatalysts plays a vital role in efficient hydrogen production. Herein, Mo 2 C/Mo 2 N heterostructure was in-situ synthesized by a two-step method for excellent hydrogen evolution performance at a universal pH range. The results show that the optimized MoCN-750-2h only needs 86.5, 102.5 and 120.5 mV overpotentials to reach 10 mA·cm −2 in alkaline, acidic and neutral media, respectively. Not only that, MoCN-750-2h had a low Tafel slope (37.2 and 88.5 mV·dec −1 ) in alkaline and neutral media, implying that catalytic kinetic is close to the level of Pt/C. These results can be attributed to reasonable C and N content in MoCN-750-2 h, optimizing the electron cloud distribution of Mo 2 C/Mo 2 N heterostructure to boost hydrogen production. Graphical Abstract MoCN heterostructure was in-situ synthesized by a two-step method for excellent hydrogen evolution performance at a universal pH range. The optimized electron cloud distribution of Mo 2 C/Mo 2 N would promote the formation of electron transfer channels, boosting the hydrogen evolution catalytic activity of the heterostructure. The MoCN heterostructure only needs 86.5,102.5 and 120.5 mV overpotentials to reach 10 mA·cm −2 in alkaline, acidic and neutral media, respectively. Not only that, MoCN-750-2 h had a low Tafel slope (37.2 and 88.5 mV·dec −1 ) in alkaline and neutral media, implying that catalytic kinetic is close to the level of Pt/C.
研究领域:
材料科学
·
电化学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Yang Shi,Pei Liu,Zhenluo Yuan,Xiaojiao Wang,Qiuming Peng,Shumin Han,Yanping Fan,Baozhong Liu
The exploitation of high-performance catalysts is essential for practical application of hydrogen production technology by ammonia borane (AB) hydrolysis. In this work, we reported an uncomplicated approach to exploit high-performance catalysts for hydrogen production from AB hydrolysis. Using the reducibility of AB, the Ru 0 /Mo 2 C MXene catalyst was synthesized using Mo 2 C MXene as carrier to hydrogen production from AB hydrolysis. The combination of Mo 2 C MXene and Ru nanoparticles exhibited remarkable catalytic performance. The TOF value was 868.6 min −1 and the hydrogen production rate reached as high as 210,464 mL min −1 g Ru −1 at 298 K. Moreover, the Ru 0 /Mo 2 C MXene catalyst showed good durability and continuously produce hydrogen for more than 4 h with a turnover number (TON) of 41293. Characterization analysis revealed that Mo 2 C MXene regulated the coordination environment of Ru, forming electron-rich Mo 2 C MXene and electron-deficient Ru sites. And excellent catalytic activity is benefiting from the enhanced interaction between Mo 2 C MXene and Ru nanoparticles, promoting the effective activation and dissociation of the reactants, which resulted in the improvement of the performance of AB hydrolysis. This work offers an innovative approach to synthesize efficient AB hydrolysis catalysts for hydrogen production.
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
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 8
·7175-7184
·
IF 4.987
Yang Chunyan,Zhang Liu,Zhu Yingming,Liu Yingying,Liu Changjun,Wu Kejing,Lu Houfang,Liang Bin
In this study, ordered mesoporous carbon materials are prepared to support β-Mo 2 C catalysts for conversion of Kraft lignin into aromatic monomers. Carbon supports with different porous structures are compared to discuss the critical role of ordered mesopores. The results show a volcano evolution of aromatic monomer yields with the increase in Mo contents over β-Mo 2 C supported on ordered mesoporous carbon, and a high aromatic yield of 0.576 g/g Kraft lignin is achieved at 280 °C for 3 h for only 10% Mo mass content. Dispersion of β-Mo 2 C and confinement of ordered mesopores contribute to the highest aromatic yield per unit Mo. The highly dispersed β-Mo 2 C on the surface of ordered mesoporous carbon exhibits the advances of confined environment and accessibility of lignin fragments to active β-Mo 2 C, resulting high activity of β-Mo 2 C for Kraft lignin decomposition.
研究领域:
材料科学
·
化学工程
·
可再生资源转化
✓ 已验证
产品关联
DOI
高影响因子
Materials Reports: Energy
·
2023
·
IF 0
Xiu-Qing Qiao,Wenxuan Chen,Chen Li,Zizhao Wang,Dongfang Hou,Bojing Sun,Dong-Sheng Li
Photocatalytic water splitting on noble metal-free photocatalysts for H 2 generation is a promising but challenging approach to realize solar-to-chemical energy conversion. In this study, Mo/Mo 2 C nanoparticles anchored carbon layer (Mo/Mo 2 C@C) was obtained by a one-step in-situ phase transition approach and developed for the first time as a photothermal cocatalyst to enhance the activity of ZnIn 2 S 4 photocatalyst. Mo/Mo 2 C@C nanosheet exhibits strong absorption in the full spectrum region and excellent photo-thermal conversion ability, which generates heat to improve the reaction temperature and accelerate the reaction kinetics. Moreover, metallic Mo/Mo 2 C@C couples with ZnIn 2 S 4 to form ZnIn 2 S 4 –Mo/Mo 2 C@C Schottky junction (denoted as ZMM), which prevents the electrons back transfer and restrains the charge recombination. In addition, conductive carbon with strong interfacial interaction serves as a fast charge transport bridge. Consequently, the optimized ZMM-0.2 junction exhibits an H 2 evolution rate of 1031.07 μmol g −1 h −1 , which is 41 and 4.3 times higher than bare ZnIn 2 S 4 and ZnIn 2 S 4 –Mo 2 C, respectively. By designing novel photothermal cocatalysts, our work will provide a new guidance for designing efficient photocatalysts.
研究领域:
材料科学
·
能源化学
·
纳米技术
✓ 已验证
DOI
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 30
·15862-15868
·
IF 8.867
Sha-Sha Yi,Jun-Min Yan,Ba-Ri Wulan,Qing Jiang
Sunlight-driven water splitting using light-absorbing semiconductor-based materials is an ongoing strategy to overcome the world-wide environmental pollution and energy crisis. The construction of core–shell-type nanostructures by coupling of the earth-abundant hydrogen generation catalyst Mo2C to the good photoabsorber CdS may be the best combination for photocatalytic hydrogen generation reaction. Thus, in this work, core–shell nanorods consisting of a CdS core and a Mo2C–C shell have been designed and synthesized for the first time. The as-prepared CdS@Mo2C–C nanorods display an excellent hydrogen generation rate of 17.24 mmol h−1 g−1 relative to pure CdS, which may result from the unique one-dimensional nanostructure, the strong interfacial interaction between the core and shell materials, as well as the broadened visible-light absorption range. What's more, the existence of C layers in the core–shell nanorods can facilitate transfer of the photogenerated holes to the outer shell of Mo2C–C, and thus protect the inner CdS from photocorrosion to finally achieve high photostability of the catalyst.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Sen Jin,Zuhao Shi,Huijuan Jing,Libo Wang,Qianku Hu,Deliang Chen,Neng Li,Aiguo Zhou
Here, we report a visible-light photocatalyst (Mo2C-MXene/CdS) with H2 production rate higher than that of state-of-the-art catalysts based on noble metals or other MXenes. The photocatalyst was constructed from Mo2C MXene, Cd(NO3)2·4H2O, and thiourea with ethylenediamine, which has an acanthosphere structure with Mo2C two-dimensional (2D) sheets covered by wurtzite CdS nanocrystals. From theoretical calculation, Mo sites in the Mo2C-MXene/CdS(110) heterostructure provide an efficient reaction site for the hydrogen evolution reaction (ΔGH* = −0.18 eV). The electronic structures demonstrate that this heterostructure has favorable band gap and band edge position for water splitting. In experimental measurements, the photocatalyst shows a H2 production rate of 17 964 μmol g–1 h–1. The H2 production is ca. 20% higher than the previously reported value of Ti3C2 MXene catalysts and ca. 11% higher than that of noble-metal catalysts. Therefore, Mo2C-MXene/CdS heterostructure is a promising catalyst with ultrahigh performance to replace noble-metal catalysts.
研究领域:
材料科学
·
催化
·
能源材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）