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
CRYSTENGCOMM
·
2023
·Vol. 25
·期 45
·6310-6316
·
IF 3.1
Lu Chen,Deling Wang,Renkun Huang,Ruowen Liang,Linzhu Zhang,Shaoming Ying,Guiyang Yan
The development of low-cost and high-efficiency non-noble metal cocatalysts is one of the important factors in promoting the separation of photogenerated carriers. In this study, we report a stable and highly active MoC@NC/ZnIn2S4 heterostructure for photocatalytic H2 evolution under visible light. The optimized MoC@NC/ZnIn2S4 composite displays an excellent photocatalytic H2 evolution rate of 45.4 μmol h−1, which was 8.3 times higher than that of ZnIn2S4. Its apparent quantum efficiency reached 51.5% at 420 nm. Moreover, the photocatalyst exhibits excellent stability and recycling capabilities. This remarkable activity can be ascribed to the modification of MoC@NC onto the ZnIn2S4 surface by forming an intimate contact interface, which can suppress the recombination of photogenerated carriers, consequently leading to superior photocatalytic H2 evolution performance. This study indicated that MoC@NC can act as an outstanding cocatalyst for promoting ZnIn2S4 photocatalytic performance.
研究领域:
材料科学
·
能源化学
✓ 已验证
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
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Science Bulletin
·
2020
·
IF 9.511
Hong-Hui Wang,Shi-Nan Zhang,Tian-Jian Zhao,Yong-Xing Liu,Xi Liu,Juan Su,Xin-Hao Li,Jie-Sheng Chen
The direct hydrogenation of CO 2 using H 2 gas is a one-stone-two-birds route to produce highly value-added hydrocarbon compounds and to lower the CO 2 level in the atmosphere. However, the transformation of CO 2 and H 2 into hydrocarbons has always been a great challenge while ensuring both the activity and selectivity over abundant-element-based nanocatalysts . In this work, we designed a Schottky heterojunction composed of electron-rich MoC nanoparticles embedded inside an optimized nitrogen-doped carbon support (MoC@NC) as the first example of noble-metal-free heterogeneous catalysts to boost the activity of and specific selectivity for CO 2 hydrogenation to formic acid (FA) in liquid phase under mild conditions (2 MPa pressure and 70 °C). The MoC@NC catalyst with a high turnover frequency (TOF) of 8.20 mol FA mol MoC −1 h −1 at 140 °C and an excellent reusability are more favorable for real applications.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemistry-An Asian Journal
·
2019
·Vol. 14
·期 7
·1013-1020
·
IF 3.698
Shuo Geng,Weiwei Yang,Yongsheng Yu
Graphical Non-precious potential : Developing noble-metal-free, earth-abundant, highly active, and stable electrocatalysts with high efficiency for both hydrogen and oxygen evolution reactions in the same electrolyte is of great importance for the development of overall water-splitting devices. Heterostructured NiC/MoC/NiMoO 4 electrocatalysts have been synthesized through a facile method and the influence of anions with same morphology on water splitting has also been studied. Developing noble-metal-free, earth-abundant, highly active, and stable electrocatalysts with high efficiency for both hydrogen and oxygen evolution reactions is of great importance for the development of overall water-splitting devices, but still remains a challenging issue. Herein, a 3D heterostructured NiC/MoC/NiMoO 4 electrocatalyst was prepared through a facile synthetic procedure. The electrocatalyst shows a superior catalytic activity and stability toward the hydrogen and oxygen evolution reactions. The optimized NiC/MoC/NiMoO 4 catalyst presents low overpotentials of 68 and 280 mV to reach a current density of 10 mA cm −2 in 1.0 m KOH for the hydrogen and oxygen evolution reactions, respectively. Assembled as an electrolyzer for overall water splitting, such a heterostructure shows quite a low cell voltage of 1.52 V at 10 mA cm −2 and remarkable stability for more than 20 h. This work provides a facile but efficient approach for the design and preparation of highly efficient bifunctional and self-supported heterostructured electrocatalysts that can serve as promising candidates in electrochemical energy storage and conversion.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 17
·5583-5588
·
IF 7.367
Xueping Zhang,Liang Huang,Yujie Han,Miao Xu,Shaojun Dong
Developing efficient and earth-abundant oxygen evolution reaction (OER) electrocatalysts is of great importance in renewable energy research. Herein, we report nitrogen-doped carbon encapsulating γ-MoC/Ni heterostructures (γ-MoC/Ni@NC) for the first time as efficient OER electrocatalysts. The composites can be controlled by the addition of a Mo source to form a nanoparticle-assembled hierarchically porous nanostructure, which can enlarge the specific surface area, thus exposing more active sites. Moreover, we demonstrate that the formation of γ-MoC@Ni heterostructures and the resulting synergistic effect between γ-MoC and Ni can facilitate the reaction kinetics, leading to significantly improved OER activity with an onset overpotential of merely 240 mV, and a low overpotential of 310 mV to afford a current density of 10 mA cm−2. This work provides a new insight into the development of highly active and inexpensive OER electrocatalysts.
研究领域:
材料科学
·
能源研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Haoquan Guo,Xinyu Lu,Yue Yang,Jinhe Wei,Lizhi Wu,Li Tan,Yu Tang,Xiaoli Gu
Alkyl phenol is an essential chemical intermediate that is in high demand in the chemical industry. The synthesis of alkyl phenols from lignin-derived molecules is one of the most promising routes for utilizing biomass resources. Herein, we report the catalytic hydrodeoxygenation (HDO) of dihydroeugenol (DHE) to alkyl phenols over a highly dispersed Pd/α-MoC catalyst with a substrate conversion of 98% and a selectivity of 96% to alkyl phenols. The Pd/α-MoC catalyst prepared by co-precipitation and temperature-programmed carbonization exhibits exceptional HDO activity under mild conditions with a low H 2 pressure (1–10 bars). The characterizations of the catalyst suggest that Pd are highly dispersed on the α-MoC matrix. The reaction mechanism was investigated using the substrate scope experiments. Under ambient pressure, the abundant oxygen vacancies and acidity sites on Pd/α-MoC enable the selective hydrodeoxygenation of lignin monomers.
研究领域:
化学工程
·
生物质利用
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Yuanxiao Ji,Jiyuan Zhang,Na Yang,Jiarui Xue,Weiye Zhang,Xuexia He,Qi Li,Zhibin Lei,Zonghuai Liu,Jie Sun
Lithium sulfur (Li-S) batteries have broad development potential in the field of electrochemical energy storage due to their high theoretical specific capacity, low cost, and environmentally friendly. However, the notorious shuttle effect of lithium polysulfides (LiPSs) during cycling process severely limits the performance improvement of Li-S batteries. In this work, carbon nanofibers (CNFs) decorated by MoC nanoparticles have been successfully established through electrospin combined with carbothermal reduction method. The effect of calcination temperature and MoC loading amount on the catalytic activity on LiPSs, as well as the electrochemical performance have been first investigated in detail. Based on the visualized adsorption and LiPSs conversion kinetics testing, the CNFs@MoC composites with 37 wt% MoC loading (CNFs@MoC-37 %) are confirmed to be the optimized sample. By using liquid-phase impregnation to load Li 2 S onto the CNFs@MoC-37 % composites to act as cathode, the assembled cells can achieve a reversible capacity of 941 mAh g −1 and 751 mAh g −1 at the current density of 0.1C and 1C respectively. The reversible capacity can still maintain at 550 mAh g −1 at 1C after 500 cycles, corresponding to the capacity decay rate of 0.054 % per cycle.
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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Tongrui Shao,Liru Cao,Lin Li,Yang Su,Baolin Hou,Jian Lin,Xiaodong Wang
Water gas shift (WGS) reaction is an important process to remove CO contaminant in industrial hydrogen resources. The efficient catalyst that can work at low temperature is keenly desired to achieve high CO conversion from the viewpoint of thermodynamic equilibrium. Here, we develop a noble-metal-free catalyst of MoC nanorod (MoC NR) with the dominant (2 0 0) facet for the low-temperature WGS reaction. It exhibits a high performance with ∼ 100 % CO conversion at 175 °C, better than conventional MoC with the dominant (1 1 1) facet or the commercial Cu-based catalyst. Moreover, it shows rather better stability due to the presence of the dominant (2 0 0) facet. Various characterizations demonstrate that this facet facilitates MoC NR possessing higher removal capability of surface oxygen species to enhance the stability and lower activation energy to endow higher performance compared with conventional MoC. This study provides important implications for the rational design of cost-effective catalysts for the low-temperature WGS reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2025
·
IF 16
Wei Liu,Anyang Wang,Jihan Zhang,Shixiang Yu,Maolin Wang,Shuheng Tian,Haoyi Tang,Ziwen Zhao,Xiao Ren,Yuzheng Guo,Ding Ma
Constructing subnanometric electrocatalysts is an efficient method to synergistically accelerate H2O dissociation and H+ reduction for pH-universal hydrogen evolution reaction (HER) for industrial water electrolysis to produce green hydrogen. Here, we construct a subnanometric Pt/α-MoC catalyst, where the α-MoC component can dissociate water effectively, with the rapid proton release kinetics of Pt species on Pt/α-MoC to obtain a good HER performance at high current densities in all-pH electrolytes. Quasi-in situ X-ray photoelectron spectroscopy analyses and density functional theory calculations confirm the highly efficient water dissociation capability of α-MoC and the thermodynamically favorable desorption process of hydrolytically dissociated protons on Pt sites at the high current density. Consequently, Pt/α-MoC requires only a low overpotential of 125 mV to achieve a current density of 1000 mA cm–2. Moreover, a Pt/α-MoC-based proton exchange membrane water electrolysis device exhibits a low cell voltage (1.65 V) and promising stability over 300 h with no performance degradation at an industrial-level current density of 1 A cm–2. Notably, even at a current of 100 A, the cell voltage remains low at 2.15 V, demonstrating Pt/α-MoC’s promising potential as a scalable alternative for industrial hydrogen production. These findings elucidate the synergistic mechanism of α-MoC and atomically dispersed Pt in promoting efficient HER, offering valuable guidance for the design of electrocatalysts in high current density hydrogen.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ru-zhou Miao,Yu-long Bao,Guang Yang,Ying-jie Sun,Xiao-jing Wang,Jun Zhao,Hui-ying Mu,Fa-tang Li
The simultaneous construction of efficient hydrogen evolution surfaces and the establishment of effective electron transport channels are crucial for improving the efficiency of photocatalytic hydrogen evolution reactions (PHERs). Molybdenum carbide materials are considered strong substitutes for Pt co-catalysts in PHERs because their electronic structure is similar to that of Pt. However, it is still challenging to enhance the kinetics of molybdenum carbide for hydrogen evolution reactions (HERs) while improving interface electron transport properties. In this study, low electronegativity heteroatoms P were introduced into metalloid MoC to adjust the overpotential of HERs while tuning the Schottky barrier between MoC and Zn 0.5 Cd 0.5 S. Due to the excellent charge separation efficiency in photocatalysts driven by the atomic-scale tuning of interfacial energetics on the prerequisite of not impairing the kinetics for surface reactions, the optimal P-MoC-modified Zn 0.5 Cd 0.5 S displayed a hydrogen evolution rate of 28.98 mmol·g −1 ·h −1 , which was 11.59 and 1.51 times higher than that of pure Zn 0.5 Cd 0.5 S and Pt-modified Zn 0.5 Cd 0.5 S, respectively. This study provides a reference for the design of a high-efficiency co-catalyst and provides a new way for the regulation of the Mott–Schottky barrier.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Chunli Cui,Genrui Zhang,Yu Yang,Tingting Wu,Lei Wang
Constructing heterojunction has been proved to be an efficient strategy for enhancing the photocatalytic performance of g-C 3 N 4 by prohibiting charge recombination and providing surface active sites. Herein, a novel structure of ultra-thin carbon bridged MoC quantum dots/g-C 3 N 4 nanosheets was constructed for the first time to facilitate carrier transfer and accelerate surface reactions. In our designed composites, a surface-to-surface contact has been formed between conductive carbon layer and g-C 3 N 4 nanosheet via ultrasonic assembly process. Moreover, there exist strong interfaces between MoC QDs and carbon layer because of the in-situ conversion method. As to this unique structure, the ultra-thin carbon layer functions as charge separation and migration high ways while the MoC QDs perform as noble-metal-free co-catalysts consuming the surface electrons promptly. Significantly, an optimal 40 wt% MoC QDs-C/g-C 3 N 4 photocatalyst (MCCN) is synthesized with a hydrogen evolution rate of 2989 μmol h −1 g −1 , which is 69.6 and 1.7 times higher than that of pure g-C 3 N 4 and Pt/g-C 3 N 4 , respectively. Our work provides new insights on designing highly efficient heterojunction photocatalysts for water splitting.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）