APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Jie Zhang,Ruiying Wang,Xiaoqin Hu,Zhipeng Sun,Xingchao Wang,Yong Guo,Lili Yang,Mengran Lou,Pengtao Wen
The fabrication of a Pt-based catalyst with high activity and stability for methanol electrooxidation is both of vital importance and challenging for direct methanol fuel cells. Herein, a catalyst support based on Co embedded into N-doped nanotube decorated mesoporous carbon (Co@NCNTs-MC) derived from metal-organic frameworks (MOFs) was synthesized by a pyrolysis method at an appropriate temperature and duration using ZIF-67 as a precursor, and melamine as an additional nitrogen source. The presence of melamine ensures adequate nitrogen content at high temperature, promotes the formation of NCNTs through the help of Co nanoparticles in the pyrolysis process and forms a mesoporous carbon structure. The optimum pyrolysis condition was found to be 800 °C for 4 h. A Pt-based catalyst was synthesized with the as-prepared Co@NCNTs-MC support which was found to significantly improve the dispersion of Pt nanoparticles and enhance the transportation of electrons and mass. Co-N x bonds are shown to provide an abundance of active sites. A Pt/Co@NCNTs-MC800-4 sample is found to show mass activities of 700.3 mA mg −1 Pt for methanol electrooxidation, which is approximately 4.5 times higher than that of 20% Pt/C. This work brings new opportunities to design and prepare promising catalyst supports for direct methanol fuel cells.
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
COMPOSITES COMMUNICATIONS
·
2024
·
IF 6.5
Xiu-Zhi Tang,Ziwen Zhao,Zijian Liao,Jianling Yue,Weiping Gong,He Zhang,Yi Wang
The incorporation of magnetic ingredients is critical for ceramic-based microwave absorbers with high efficiency. However, this task is becoming challenging due to the dispersion and oxidation issues. In this study, metal-organic framework (MOF) ZIF-67 was employed as the precursor of magnetic compounds and combined with a polymer solution to fabricate SiC textiles using the electrospinning technique. The microstructure analysis confirmed the successful introduction of MOF particles within the SiC nanofibers. Further examination of chemical compositions and magnetic properties revealed the encapsulation of magnetic compounds in hybrid SiC textiles. Since the applied fabrication approach ensures a superior dispersion and protection of metal compounds in a ceramic matrix, the microwave absorption of SiC fabric with both dielectric loss and magnetic loss exhibits a high reflection loss of −59.4 dB and a wide effective absorption band of 5.70 GHz. The current fabrication strategy for fabricating microwave absorbers with dual loss mechanisms advances the development of ceramic-based microwave absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2016
·Vol. 23
·期 3
·637-643
·
IF 5.771
Changting Wei,Hongjing Wang,Kamel Eid,Jeonghun Kim,Jung Ho Kim,Zeid Abdullah Alothman,Yusuke Yamauchi,Liang Wang
Graphical Low-cost and efficient : A hybrid consisting of cobalt-embedded nitrogen-doped carbon nanotubes and nitrogen-doped reduced graphene oxide (Co-NCNT/NrGO-800) was prepared by simple pyrolysis. The combination of nanotubes and graphene, and the efficient doping with cobalt and nitrogen, greatly contribute to the excellent oxygen reduction. To develop low-cost and efficient oxygen reduction reaction (ORR) catalysts, a novel hybrid comprising cobalt-embedded nitrogen-doped carbon nanotubes and nitrogen-doped reduced graphene oxide (Co-NCNT/NrGO-800) was simply prepared by pyrolysis. The combination of nanotubes and graphene, and the efficient doping with cobalt and nitrogen, greatly contribute to the excellent ORR performance. This optimized Co-NCNT/NrGO catalyst exhibits a positive onset potential of 0.91 V and a half-wave potential of 0.82 V, combined with a relatively low peroxide yield, better durability, and better methanol tolerance than commercially available Pt/C, which makes it a promising candidate as a low-cost and effective non-precious-metal ORR catalyst.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Ruijing Wang,Peng Sun,Qin Yuan,Rongrong Nie,Xuefeng Wang
Metal-embedded nitrogen-doped carbon materials have been proposed as novel hydrogen evolution reaction (HER) catalysts to replace platinum-based materials, while these alternatives usually exhibit low activity and gradual deactivation during their use. Here, leaf-like cobalt-embedded nitrogen-doped porous carbon sheet (Co-NC) for the HER is obtained by simple pyrolysis of a two-dimensional metal organic framework . The Co-NC annealed at 800 °C exhibits large surface area and the active metallic cobalt species embedded in the N-doped carbon layers , which leads to the lower overpotential, higher current density , and superior durability in alkaline media . However, the Co-NC annealed at 600 °C shows abundant nitrogen-coordinated cobalt species, which favors the high HER activity under acidic condition. These structural properties of the Co-NC enable the efficient HER activity by increasing the active sites and enhancing mass transfer of water molecules or protons at the interface where the reaction takes place.
研究领域:
材料科学
·
电化学
·
能源催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Dingding Meng,Chi Zhang,Yi Liang,Weiye Qiu,Fanping Kong,Xin He,Mei Chen,Ping Liang,Zhonghua Zhang
Electrospinning is an effective technique to fabricate one-dimensional materials. In this study, cobalt-embedded carbon nanofibers (Co@CNFs) are obtained via carbonization of electrospun cobalt Prussian blue analogue (Co-Co PBA) under nitrogen atmosphere. The Co@CNFs have metallic cobalt surrounded by graphitic carbon shells and possess high specific surface area, rich porosity, high graphitic degree, and rational nitrogen doping. The structure merits endow them with excellent electrocatalytic performances for oxygen reduction reaction (ORR): an onset potential of 0.867 V vs. RHE and 0.784 V vs. RHE at j = − 3 mA cm −2 with a four-electron transfer process. Through a further mild oxidation process , we obtain Co 3 O 4 nanoparticles-embedded nitrogen-doped carbon (Co 3 O 4 @CNFs) with spindle-like morphology. When working as the anode materials for lithium-ion batteries (LIBs), Co 3 O 4 @CNFs show high specific capacity, good stability, and excellent rate capability. The Co 3 O 4 @CNFs anode delivers a discharge specific capacity of 1404 mA h g −1 after 100 cycles at a current density of 100 mA g −1 and about 500 mA h g −1 after 500 cycles at 2000 mA g −1 . The diffusion- and capacitive-controlled processes both contribute to the charge storage of the Co 3 O 4 @CNFs electrode. This study provides a new strategy to fabricate the excellent electrocatalysts for ORR and anode materials for LIBs via facile electrospinning.
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
Nano-Micro Letters
·
2019
·Vol. 11
·期 1
·1-11
·
IF 9.043
Tang Zeming,Zhao Yingxuan,Lai Qingxue,Zhong Jia,Liang Yanyu
Abstract A novel nonprecious metal material consisting of Co-embedded porous interconnected multichannel carbon nanofibers (Co/IMCCNFs) was rationally designed for oxygen reduction reaction (ORR) electrocatalysis. In the synthesis, ZnCo 2 O 4 was employed to form interconnected mesoporous channels and provide highly active Co 3 O 4 /Co core–shell nanoparticle-based sites for the ORR. The IMC structure with a large synergistic effect of the N and Co active sites provided fast ORR electrocatalysis kinetics. The Co/IMCCNFs exhibited a high half-wave potential of 0.82 V (vs. reversible hydrogen electrode) and excellent stability with a current retention up to 88% after 12,000 cycles in a current–time test, which is only 55% for 30 wt% Pt/C.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 40
·15536-15545
·
IF 8.262
Zhen Zhu,Yan Yang,Yue Guan,Juanhong Xue,Lili Cui
Hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) are vital in renewable energy technologies, such as water splitting and fuel cells. Nevertheless, increasing efforts have been paid to develop non-precious metal catalysts as alternatives to noble metal catalysts for HER and ORR. However, how to rationally design and construct an advantageous catalyst is still challenging. Here, a novel cobalt-embedded in nitrogen-doped graphene aerogel (Co–N–GA) catalyst is firstly rationally designed and synthesized by employing a facile strategy of implementing the confined growth of metal organic frameworks (MOFs) within graphene aerogels (GAs). It is worth noting that the Co–N–GA exhibits hierarchical porosity involving micropores, mesopores and macropores, as well as a high surface area (466.6 m2 g−1). More importantly, benefiting from the synergetic effect of hierarchical porosity, high surface area, N-doped carbon and the inner Co metal, the catalyst Co–N–GA displays extraordinarily superior activity for both HER at various pH values and ORR along with better stability. Especially for HER, the onset overpotential, overpotentials@10, 100 mA cm−2 and Tafel slope on the catalyst Co–N–GA in 0.5 M H2SO4 are 0 mV, 46 mV, 183 mV and 33 mV dec−1, respectively. Most importantly, these values are much lower than those of almost all prepared noble-metal-free HER catalysts, indicating the excellent activity for HER of our as-prepared catalyst Co–N–GA. Herein, our strategy opens a new platform to construct a variety of hierarchically porous GA-based catalysts that serve as superior electrocatalysts in energy storage and conversion technologies.
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
CHINESE JOURNAL OF CATALYSIS
·
2020
·
IF 6.146
Mudassar Javed,Shilin Cheng,Guihua Zhang,Cederick Cyril Amoo,Jingyan Wang,Peng Lu,Chengxue Lu,Chuang Xing,Jian Sun,Noritatsu Tsubaki
A series of Co-imbedded zeolite-based catalysts were synthesized following a facile solvent-free grinding route. The catalytic performance for direct syngas conversion to gasoline range hydrocarbons was compared with their counterpart Co-impregnated zeolite-based catalysts. Successful transformation of solid raw materials to targeted zeolite was confirmed by XRD, SEM, STEM, and N 2 physisorption analysis. An in-depth study of acidic strength and acidic site distribution was conducted by NH 3 -TPD and Py-IR spectroscopy. Acidic strength showed a pivotal role in defining product range. Co@S1, with the weakest acidic strength of silicalite-1 among three types of zeolites, evaded over-cracking of product and exhibited the highest gasoline and isoparaffin selectivity (≈70% and 30.7%, respectively). Moreover, the solvent-free raw material grinding route for zeolite synthesis accompanies several advantages like the elimination of production of wastewater, high product yield within confined crystallization space, and elimination of safety concerns regarding high pressure due to the absence of the solvent. Facileness and easiness of the solvent-free synthesis route together with promising catalytic performance strongly support its application on the industrial scale.
研究领域:
催化化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Depeng Wang,Xintao Zuo,Huiling Liu,Cheng Wang
Developing highly efficient bifunctional oxygen electrocatalysts via cost-effective methods is of great significance for energy storage and conversion systems but still full of challenges. In this work, a simple and eco-friendly method which involves a sol-gel pretreatment on multiple precursors and subsequent pyrolysis is designed to synthesize Co nanoparticles embedded and nitrogen-doped porous carbon (Co@NC). The sol-gel pretreatment ensures the high dispersion of all precursors, which is beneficial to the formation of uniform and highly dense active sites. After pyrolysis, acid treatment removes the unencapsulated Co nanoparticles on the surface to form porous structure and increase the mass activity. Benefiting from the synthetic strategy, the porous Co@NC-850 with large surface area, high density of active sites (graphitic N, pyridinic N and Co-N x ) exhibits comparable oxygen reduction performance ( E 1/2 = 0.85 V vs. reversible hydrogen electrode) to that of commercial Pt/C and better oxygen evolution activity (with an overpotential of 350 mV at 10 mA cm −2 ) with respect to RuO 2 . The potential gap Δ E (between the oxygen evolution potential at 10 mA cm −2 and oxygen reduction E 1/2 ) for Co@NC-850 is only 0.73 V. Compared with the state-of-the-art bifunctional oxygen electrocatalysts, Co@NC-850 shows obvious advantages in bifunctional activity and durability. The results in the present work will shed light on the development of other carbonaceous materials as the bifunctional oxygen electrocatalysts for energy storage and electrochemical devices .
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
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Yue Yang,Mengyuan Wang,Penghui Shi,Junfeng Wu,Yulin Min,Qunjie Xu,Yifei Guo
The transformation of waste biomass into nitrogen-doped carbon-based functional materials is recognized as an economical route for energy production and conversion. Waste diapers contain urea that could be used as a nitrogen source, were considered renewable biomass. BPA, a widely used environmental endocrine disruptor, produces estrogen effects in the human body and is characterized by low concentrations and high toxicity in the environment. Here, a simple method of obtaining cobalt embedded waste diaper carbon (Co-WDC) using abandoned diapers is reported and used for an advanced oxidation process. Co-WDC completely removed 20 mg L −1 BPA from a solution within 6 min with a degradation rate constant of 0.68 min −1 . The LC–MS test revealed that BPA is decomposed into small molecules, and TOC was greatly reduced. Electron paramagnetic resonance and quenching experiments demonstrated the Co-WDC degradation system acted through two pathways, radical and non-radical pathway where 1 O 2 was the dominant species. Material characterization and discussion of the mechanism revealed that the introduction of Co mainly formed a metal-nitrogen structure that induced peroxymonosulfate to produce 1 O 2 , which participated in BPA degradation in the Co-WDC system. This work should generate interest in the recycling of waste biomass for peroxymonosulfate activation and environmental modification.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Xiaotong Hou,Zhonghan Cheng,Zhonghui Zheng,Somboon Chaemchuen
A straightforward in-situ thermal (IST) method to synthesize cobalt-embedded nitrogen-doped carbon matrix (Co@NC) is developed. The IST method shows an advantage in a single-step process without any solvent. Inside the IST process, the analysis techniques with temperature function were applied to investigate the material evolution into the Co@NC. The intermediate structure, like zeolitic-imidazole framework-67, firstly obtains at the low-temperature stage before being derived into Co@NC at the high-temperature stage of the IST process. Several analysis techniques are applied to verify the structural properties of Co@NC. Taking advantage of dual acid-base sites, the Co@NC exhibits high potential heterogeneous cobalt-based carbon catalyst for three model reactions. Moreover, the magnetic character on Co@NC is profitable in the advanced recyclability process over the heterogeneous catalyst.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 31
·14726-14732
·
IF 3.3
Lingting Huang,Yuqing Ren,Zhen Yang,Ruijin Zeng,Dianping Tang
Based on the electro-oxidation mode, electrochemical sensors provide an appealing evaluation tool for uric acid (UA) detection. However, improvements in the field of high-performance electrocatalysts remain necessary to enable wide-range and ultrasensitive detection of UA in this way. In recent years, the research and development of thermally treated metal (M) and nitrogen (N) co-doped carbon (M–N–C) catalysts, along with the usage of metal–organic framework materials as precursors, has substantially increased the performance of non-precious metal oxygen reduction catalysts, rendering them a potential species of the active substance. In this work, we synthesized cobalt metal-embedded nitrogen-doped carbon frameworks (Co–CN) through a host–guest synthetic strategy. An electrochemical sensing system was constructed for the accurate detection of UA molecules utilizing the excellent UA electrooxidation performance of Co–CN. The electro-oxidation reaction exhibits double electron/double proton transfer, and a response current signal can be obtained using differential pulse voltammetry (DPV), establishing a correlation between the measured UA concentration and the strength of the DPV current. The target UA concentration and DPV current density exhibited a dose-dependent relationship with a dynamic range of 2–120 μM and a limit of detection of 0.55 μM. During measurement, this sensing approach revealed good accuracy, high specificity, and adequate storage stability. It is worth noting that this detection system introduces a fresh approach for the development of sensitive, portable, and reasonably priced human metabolite analysis in wearable health monitoring devices.
研究领域:
分析化学
·
生物医学工程
·
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）