ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Qin Wu,Ruichen Chen,Pengju Su,Daxin Shi,Yaoyuan Zhang,Kangcheng Chen,Hansheng Li
Carbon-based materials derived from metal-organic framework compounds have tunable chemical composition , morphology, and electrochemically active surface combined with good electrical conductivity and stability. In this work, Fe(OH) 3 grows on a zeolitic imidazolate framework , 2-Methylimidazole cobalt salt (ZIF-67), through oxidation and deposition. The Co 9 S 8 /NC@FeCoS 2 /NC composites with hollow yolk shell structure (HYS-Co 9 S 8 /NC@FeCoS 2 /NC) is prepared through solvothermal sulfidation combined with high-temperature carbonization using ZIF-67@Fe(OH) 3 as the precursor. A dye-sensitized solar cell assembled with HYS-Co 9 S 8 /NC@FeCoS 2 /NC as a counter electrode achieves a photovoltaic conversion efficiency of 7.07% (PCE Pt = 7.36%). The reason for this phenomenon is that the hollow yolk shell structure of Co 9 S 8 /NC@FeCoS 2 /NC material has a high specific surface area, which affords a good deal of active sites and promotes the contact between electrolyte and catalytic sites. The Fe-Co bimetal center synergies with each other to catalyze the reduction of iodide ion, showing a high catalytic activity. Besides, the material has good electrochemical stability in iodide-based electrolysis.
研究领域:
材料科学
·
电化学
·
太阳能
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2015
·
IF 2.184
Kai Wang,Dabin Liu,Sen Xu,Gaowen Cai
2-Ethylhexyl nitrate (EHN) and nitrocellulose (NC) are commonly used energetic materials that have caused many thermal runaway reactions and explosions worldwide, and their thermal stabilities have always been an important issue. Based on the results of Roduit et al. (2013), differential scanning calorimetry (DSC) was used in this study to investigate the thermal history’s influence on the thermal stabilities of EHN and NC at different heating rates. The decomposition kinetics of EHN and NC were determined by the Friedman isoconversional method. The kinetic parameters with heat balance were analysed and used for the simulation of the adiabatic behavior time to the maximum rate under adiabatic conditions (TMR ad ). The results indicated that the thermal history significantly influenced the dynamic DSC curves, decomposition kinetics and thermal stability of NC, which decomposes autocatalytically. The influence was negligible on EHN, whose decomposition proceeds according to the “ n th order” law.
研究领域:
化学
·
材料科学
·
安全工程
✓ 已验证
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Xiaoming Li,Zeming Yuan,Zhenyang Li,Chenxu Liu,Tingting Zhai,Yanghuan Zhang,Tao Li
Magnesium metal and its hydride have the characteristics of high hydrogen storage capacity, which is suitable for storing hydrogen energy. In this paper, VS 2 /NC catalyst supported on nanosheet carbon was synthesized by hydrothermal method with organic matter as raw material, then the MgH 2 + x wt.% VS 2 /NC ( x = 0, 3, 6, 9) composites were prepared by ball milling with MgH 2 . The phase characterization of the composite material showed that the VS 2 and MgH 2 phases in the composite material remain stable during ball milling and subsequently, the hydrogen absorption/desorption cycle. There were V 4+ and V 2+ ions (an atomic ratio of 3.77:1) in the catalyst. At 593 K, the capacities of the composites were 5.71, 6.11, 5.62, and 5.33 wt.% H 2 , respectively. The time to reach the maximum hydrogen desorption capacity of 95% was 190, 30, 20, and 23 min, respectively. The dehydrogenation activation energy of the material with x = 6 is reduced by nearly 50 kJ/mol H 2 . The initial dehydrogenation temperature of the material decreases to 323 K. Because of the valence state transition between V ions, the band gap of the composite material is narrowed, which significantly improves the hydrogen absorption and desorption reaction kinetics.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Jihan Wu,Ying Chang,Shaohong Guo,Aiju Xu,Jingchun Jia,Meilin Jia
Ruthenium-based nanomaterials are considered to be promising electrocatalysts for HER due to their higher activity. However, the active site exposure is low, and the catalytic mass activity is low. In order to achieve the particular aims, several types of engineering, such as crystal engineering, topography engineering, heterostructures and support engineering, have been used to catalysts. Here we report RuO 2 supported on CeO 2 -NC, owing to the abundant heterostructures and the presence of oxygen vacancies, the RuO 2 /CeO 2 -NC catalyst showed outstanding HER performance (98.2 mV, 53 mV and 298 mV@100 mA cm −2 in acidic, alkaline and neutral, respectively). Moreover, RuO 2 /CeO 2 -NC also has an excellent electrocatalytic durability for 40 h. The experimental achievements show that oxygen vacancies and heterostructures could jointly enhance performance of catalyst HER.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Zhuozheng Hong,Zili Xu,Zhengtao Wu,Hao Zhang,Ping Li,Xun Xu,Shuwang Duo
Tungsten-based nitrides are ideal hydrogen evolution reaction (HER) electrocatalysts owing to their Pt-like electronic structures, high electrical conductivity, and good corrosion resistance. However, the conventional preparation of tungsten-based nitride electrocatalysts suffers from environmentally hazardous sources and high-temperature nitridation processes, which usually restrict HER activity. Herein, we report the direct synthesis of W 2 N on metal–organic framework (MOF)-derived Co-NC microarrays using magnetron sputtering. Co-NC microarray support increased the number of surface activity sites that were exposed to W 2 N. Moreover, the formation of Co-NC@W 2 N Schottky heterojunctions significantly facilitated charge transfer between Co-NC and W 2 N. The Co-NC@W 2 N heterojunctions showed outstanding HER activity with an overpotential of 55 mV in reaching a current density of 10 mA cm −2 . Notably, Co-NC@W 2 N exhibited superior HER performance to Pt/C catalyst at high current densities. This study provides a simple and environmentally friendly approach for fabricating high-performance metal-nitride catalysts for water splitting.
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
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2025
·
IF 14.3
Chenxu Liu,Zeming Yuan,Wei Li,Tingting Zhai,Zhonggang Han,Xinfang Zhang
MgH 2 is widely considered a great potential solid hydrogen storage material along with hydrogen energy and is recognized as a kind of renewable energy. However, its poor hydrogen absorption and desorption kinetics and high thermodynamic stability limit its application. In this work, CeO 2 @NC (Nano-Carbon supported CeO 2 particles) nanosphere catalysts were synthesized by a one-step hydrothermal method, and the particle size of CeO 2 was about 7 nm and MgH 2 + x wt.% CeO 2 @NC ( x = 0, 2, 4, 6, 8) composites were prepared by ball milling. It was found that the generation of oxygen vacancy defects and the multivalent environment of carbon-supported Ce can play the role of hydrogen pump and synergistically catalyze MgH 2 . Adding a carbon layer prevents nano-effect generation to a certain extent, which makes H atoms diffuse rapidly. The results show that MgH 2 + 6 wt.% CeO 2 @NC can release 5.89 wt.% H 2 in 50 min at 593 K, and MgH 2 without catalyst can only release 0.31 wt.% H 2 . As the amount of catalyst added increases, the dehydrogenation activation energy of the composite material decreases by 31.11 kJ/mol H 2 . Through density functional theory calculation, it was found that the adsorption energy of the material increased by 1.21 eV after the addition of the catalyst, and the Fermi level of the density of states of the composite increased, which accelerated the electron transfer rate. This study can help workers catalytically modify the hydrogen storage performance of MgH 2 . Introducing oxygen vacancy defects in carbon-based supported multivalent transition metal oxide catalysts gives them a unique electronic structure and excellent catalytic activity.
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
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
ACS Applied Nano Materials
·
2020
·
IF 0
Shichuan Su,Long Huang,Shan Su,Chunfeng Meng,Hu Zhou,Liuting Zhang,Ting Bian,Aihua Yuan
The construction of active and durable electrocatalysts based on a high abundance of elements toward oxygen reduction reaction (ORR) is critical for proton-exchange membrane fuel cells and metal–air batteries. Here, a composite nanostructure composed of Fe/Fe3C-NC nanosheets and carbon nanotubes (G-Fe/Fe3C-NC/CNTs) was designed by simply annealing a glucose-chelated Fe-coordinated metal–organic frameworks. The introduction of glucose can not only effectively prevent the collapse of the initial two-dimensional (2D) leaflike zeolitic imidazolate frameworks (ZIFs) during the carbonization process but also boost the growth of carbon nanotubes (CNTs). Benefiting from efficient Fe/Fe3C and Fe–Nx moieties, high specific surface area, and electron-conducting highways provided by the unique composite structure, the obtained G-Fe/Fe3C-NC/CNTs electrocatalysts achieved an impressive ORR activity with a higher positive onset potential of 1.02 V and half-wave potential of 0.87 V over the commercial Pt/C. Significantly, it also exhibits outstanding stability after 6000 cyclic voltammogram (CV) cycles with nearly negligible decay in half-wave potential, which makes it one of the promising Pt-free catalysts for ORR.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Yao Tong,Tianhua Yang,Jian Wang,Bingshuo Li,Haijun Zhang,Rundong Li
Hydrodeoxygenation (HDO) of lignin-derived phenolic compounds plays a crucial role in the production of renewable biofuels. In this regard, a series of different Co@NC catalysts were prepared with ZIF-67 as a sacrificial template by modulating the catalyst pyrolysis temperature and used for the catalytic hydrodeoxygenation of lignin-derived phenolic model compound 4-ethylphenol for the preparation of cyclohexanols/ cyclohexanes. The results showed that the low-temperature pyrolysis will retain a large number of CoO x compounds, which led to a high dispersion of Co. For Co@NC catalysts, the uniformly dispersed Co component facilitated the adsorption and transfer of hydrogen, and the exposed surface of the carrier promoted the adsorption of reactants. The pyrolysis temperature also played a crucial role in the differences in catalyst crystal surface, specific surface area, acid strength distribution and oxygen vacancies. Co@NC catalyst prepared at 600 °C has a stronger hydrogen absorption capacity, the largest specific surface area and a higher number of oxygen vacancies. Therefore, the Co@NC-600 catalyst showed the best HDO activity. Under the mild conditions (220 °C, 2.5 h and 3 MPa H 2 ), the conversion of 4-ethylphenol was close to 100 %, and the selectivities of 4-ethylcyclohexanol and ethylcyclohexane were 62.7 % and 10.8 %, respectively.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 9
·2452-2460
·
IF 4.4
Xiao Tan,Suitao Qi,Guangxu Cheng,Chunhai Yi,Bolun Yang
As the ideal NO removal technology, the biggest challenge associated with the direct catalytic decomposition of NO is the development of highly active deNOx catalysts at low temperatures. Herein, a composite metal catalyst, Rh(0.2)/NC-MnFe, was prepared via impregnation for the low-temperature direct decomposition of NO, which exhibited 99.6% NO conversion and 63% N2 selectivity at 150 °C, and nearly 100% NO conversion and 98% N2 selectivity at 200 °C. The characterization results showed that the Rh(0.2)/NC-MnFe catalyst possessed a regular nanocage structure, good crystallinity, and suitable specific surface area. Its excellent low-temperature activity was attributed to the transfer of the dissociated O of NO from the Rh active site to the NC-MnFe support, which effectively inhibited the deactivation of Rh. The mechanism analysis indicated that NO adsorbed on the Rh(0.2)/NC-MnFe catalyst surface can generate NO2− and NO3−, and then the adsorbed NO together with NO3− is converted to NO2− species accompanied by the release of N2O. At last, NO2− is decomposed to N2.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Qing-Shuai Zhang,Yu-Le Wang,Li Yue,Yu-Dong Shan,Song-Hai Wu,Yong Liu,Xu Han
Although selective oxidation of benzene to phenol (SOBP) by H2O2 is an important chemical process, overoxidation of benzene by the produced nonselective •OH during the activation of H2O2 inevitably reduces the oxidation selectivity. We, therefore, attempt to mediate the oxidation selectively by using electrophilic KHCO3 in the oxidation system. In this study, Mo–Cu/NC has been successfully synthesized via ball-milling bimetallic Mo–Cu and N-doped carbon, which exhibits high reactivity in SOBP by H2O2 and KHCO3 with a desirable phenol yield of 25.1% and selectivity of 100%. A series of characterizations and DFT calculations reveal that the reaction between H2O2 and KHCO3 produces HCO4–, which is then moderately activated on Mo1Cu2/NC via the nonradical pathway with the formation of Mo-(η2-O2) peroxo. Meanwhile, Ov at Mo1Cu2/NC facilitates the adsorption of benzene, which is then selectively oxidized by Mo-(η2-O2) peroxo to phenol via the oxygen atom transfer pathway. This study provides new insights on the importance of Mo-(η2-O2) peroxo mediated by H2O2–KHCO3 in selective oxidation of aromatic C–H bond via the nonradical pathway.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Pengcheng Wang,Qingqing Jiang,XingYu Li,Xuedong Wang,Juncheng Hu
Generally, researchers focus on the regulation of metal sites rather than surrounding nonmetals in photothermal CO 2 hydrogenation reaction. Herein, concerning the role of non-metallic N species, a series of Co/NC-T catalysts have been fabricated via high-temperature pyrolysis of Zeolitic Imidazolate Frameworks-67. The CO 2 conversion rate shows a consistent tendency with the ratio of graphitized-N species while the product selectivity is closely related to the coordination state of Co-N x species. Co/NC-800 catalyst achieves high CO 2 conversion rate of 758 mmol g cat -1 h -1 with CH 4 selectivity of 99.6 %. After adding extra graphitized-N species, the CO 2 conversion rate could further enhance to 80.2 % for N-Co/NC-2. The role of N species in photothermal CO 2 hydrogenation reaction has been investigated in details, providing new insights for the design of metal organic frameworks derived metal/N-doped carbon catalysts.
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
危险品化学品经营许可证（带存储）