INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Jianfei Li,Qichang Wang,Wenjie Zhang,Kai Zhang,Dekui Shen
The coupling of cobalt and cobalt phosphides has been demonstrated to be an efficient strategy to enhance the catalytic activity for hydrogen evolution reaction (HER). Herein, the lignin-based carbon encapsulated cobalt/cobalt phosphides heterojunctions (Co/Co 2 P@LGC) was synthesized successfully on the lignin-based carbon by carbothermal reduction integrated with post-phosphidation. The strong coupling interaction in the heterostructure promoted the establishment of a distinct synergy effect between Co and P atoms, resulting in the redistribution of electronic structure. The outstanding porous sheet structure of lignin-derived carbon facilitated the exposure of more accessible active sites and self-dopants were conducive to the formation of more carbon defects. As expected, the best catalysts, Co/Co 2 P@LGC-450 exhibited excellent HER performance in 0.5 M H 2 SO 4 , which afford a current density of 10 mA/cm 2 with only 150 mV and a Tafel slope of 86 mV dec −1 , as well as a robust stability for 120 h at 10 mA cm −2 . This research not only presented a facile method for heterostructure electrocatalysts preparation, but also offered crucial insights into the lignin valorisation.
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
Science Bulletin
·
2024
·
IF 18.8
Wei Lv,Zilei Shen,Junlin Liu,Xudong Li,Fang Ding,Dongyue Zhang,Licheng Miao,Xuefeng Lyu,Ruijie Li,Miaomiao Wang,Yiming Li,Jingwen Meng,Chao Xu
In this study, we successfully synthesized a δ-MnO 2 cathode with O vacancies, encapsulated by C derived from pyromellitic acid, using a facile hydrothermal method followed by annealing in an Ar atmosphere. The cathode’s structural stability and charge transfer kinetics are enhanced by inhibiting the formation of the by-product Zn 4 SO 4 (OH) 6 ·4H 2 O, regulating the Mn valence state, and suppressing the Jahn–Teller effect through the synergy of C encapsulation and O vacancies. This results in remarkable electrochemical performance, including a large capacity of 421.2 mAh g −1 at 0.1 A g −1 , a high specific energy density of 595.53 Wh kg −1 , and exceptional long-cycle life stability with 90.88% over 4000 cycles at 10 A g −1 , together with superior coulombic efficiency (∼100%) in pure ZnSO 4 electrolyte. Moreover, the cathode materials demonstrate specific antitumor efficacy. In brief, this work introduces an in situ synthetic C encapsulated δ-MnO 2 with O vacancies expected to be applied in both large-scale energy storage and biomedicine.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Tungsten
·
2025
·
IF 11.2
Li Ya-Ru,Jin Tao,Pan Kun-Ming,Xu Liu-Jie,Li Hao-Jie,Pan Sai-Fei,Ren Yong-Peng,Wei Shi-Zhong
The exploration of highly active and stable bifunctional catalysts based on structural adjustment and charge redistribution is imperative toward overall water splitting. The graphitized carbon encapsulation and the introduction of zinc atoms could enhance conductivity and optimize the electronic structure of catalysts, thereby improving the activities of the oxygen and hydrogen evolution reactions (OER and HER). Herein, a carbon-encapsulated CoS 2 and Zn 0.76 Co 0.24 S composite with porous structure (CoS 2 /Zn 0.76 Co 0.24 S@C) is constructed for overall water splitting by sulphurating a precursor of metanilic guest-intercalated Co Zn-layered double hydroxide (CoZn-LDH) host. Consequently, CoS 2 /Zn 0.76 Co 0.24 S@C reveals lower overpotentials of 260 and 152 mV at 10 mA·cm −2 for OER and HER, respectively, outperforming those of CoS 2 , CoS 2 @C and CoS 2 /ZnS. For overall water splitting, a CoS 2 /Zn 0.76 Co 0.24 S@C-based electrolysis cell exhibits a low cell voltage of 1.66 V at 10 mA·cm −2 with a retention of 81% after 40 h, indicating satisfactory stability. Density functional theory calculations further demonstrate that the encapsulated carbon layer could tune the d-band center of CoS 2 and Zn 0.76 Co 0.24 S. The cooperation of cobalt sulfide with zinc atoms could reduce the work function and promote electronic redistribution, thus enhancing conductivity and boosting the OER/HER kinetics of the catalyst. This work provides an effective strategy for obtaining high conductivity, acceptable activity, strong stability and cost-effective electrocatalysts for 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
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 1
·010536
·
IF 4.316
Huan Kang,Liming Xu,Yue Cai,Yao He,Jingkun Xu,Weiqiang Zhou
Binder-free and flexible oxygen-vacancy CeO2@C core–shell nanocomposites directly anchored on carbon cloth (CC) are prepared via a simple two-step process, in which CeO2 nanoparticles are hydrothermally fabricated and mixed with polyvinylpyrrolidone (PVP) composites, subsequently, as-formed CeO2@PVP composites coated on CC are calcined at 700 °C. The morphologies, structures and electrochemical properties of as-obtained CeO2@C nanocomposites are studied by SEM, HRTEM, XRD, XPS and electrochemical techniques, respectively. The CeO2@C nanocomposites are composed of the CeO2 core with diameter of about 10 nm and the carbon shell with thickness of about 1.5 nm. The electrochemical results reveal that the CeO2@C nanocomposites show a wide electrochemical active window of −1.0 ∼ 0.8 V and a specific capacitance of 141.56 F g−1 at 1 A g−1 in 1.0 M Na2SO4 electrolyte. In addition, an asymmetric supercapacitor (ASC) assembled with CeO2@C and poly(3,4-ethylene dioxythiophene) (PEDOT) can work in the wide operational voltage region of 2.0 V and deliver the energy density of 11.12 Wh kg−1 at 2000 W kg−1. The present study indicates that the CeO2@C will have a greater advantage in terms of energy density for CeO2 and its carbon-based composites supercapacitor electrodes.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Bolong Jiang,Yuhan Zhang,Huan Wang,Kun Liu,Nan Jiang,Jiayou Li,Hua Song,Yanguang Chen
Hydrodeoxygenation (HDO) plays a crucial role in upgrading pyrolysis-oil derived from biomass. Here we describe a method for fabricating a carbon-encapsulated nickel metal–acid bifunctional catalyst (Ni@C/RCS-Al) supported on aluminum-doped radial channel silica (RCS-Al). This catalyst exhibits a large surface area and highly dispersed accessible active sites, achieved through a combination of salicylate- and MOF-assisted strategies. The RCS-Al was prepared by a one-pot salicylate-assisted hydrothermal method in an aqueous phase containing an Al source, which is simple, has a high yield, and saves time. The results show that Ni@C/RCS-Al displays a well-defined radial channel pore structure with a mesopore diameter of 31.1 nm, which can significantly increase the number of accessible active sites and accelerate mass transfer. The MOF-assisted strategy leads to the formation of highly dispersed smaller carbon-encapsulated nickel nanoparticle active sites, and Al doping contributes to the adjustable acid sites, demonstrating that Ni@C/RCS-Al is a metal–acid bifunctional catalyst. Importantly, the kinetics study revealed a high reaction constant for the constructed Ni@C/RCS-Al catalyst. Ni@C/RCS-Al demonstrates remarkable performance in HDO, achieving complete m -cresol conversion and 100 % selectivity to the target product methylcyclohexane within a brief period of 75 min (T = 250 °C p = 2 MPa, m-cresol/catalyst (g) = 7.5). This exceptional performance stems from its radial channel pore structure and optimization of metal–acid sites. The thin carbon layer on the Ni surface contributes to its superior stability and water resistance, as verified by an experimental study and DFT calculations. This work opens up a new idea for the application of radial channel silica-supported catalysts in various reactions.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Zhimin Ren,Zhiyu Wang,Chao Chen,Jia Wang,Xinxin Fu,Chenyao Fan,Guodong Qian
ABSTRACT In this paper we report a novel architecture of three-dimension (3D) carbon framework to encapsulate tetrahedron ZnO nanocrystals that serves as an anode material for lithium-ion batteries (LIBs). The ZnO@C composites are prepared via a simple internal-reflux method combined with subsequent calcination in argon. The amorphous carbon is formed on the surface of the ZnO crystals by in situ carbonization of the surfactant, which leads to a strong connection between the carbon framework and the active materials and guarantees faster charge transfer on the electrode. The ZnO crystal calcined at 500°C (ZnO@C-5) possesses regular tetrahedron shape with a side length of 150-200 nm and all of them are uniformly anchored among the network of amorphous carbon. The developed ZnO@C structures not only improve the electronic conductivity of the electrode, but they also offer a larger volume expansion of ZnO during cycling. As a result, the ZnO@C-5 demonstrates a higher reversible capacity, ultralong cycle life and better rate capability than that of the ZnO@C-7 and pure ZnO crystals. After 300 cycles, the ZnO@C-5 demonstrates a high capacity of 518 mAhg −1 at a current density of 110.7 mAg −1 . Moreover, this simple approach prepared the 3D composites architecture could shed light on the design and synthesis of other transition metal oxides for energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Feiming Chen,Zilong Chen,Ziyang Dai,Shaofeng Wang,Zhenbao Zhang,Dengjie Chen
Carbon-encapsulated SnO 2 hollow spheres were fabricated by a self-templating method from Sn spheres for lithium-ion batteries (LIBs). High-temperature annealing (e.g., 700 °C) inevitably led to the formation of Sn on the exterior surface, which was disadvantageous for long-term cycling. In contrast, the preparation at an optimal annealing temperature of 600 °C coupled with subsequent acid etching completely encapsulated the SnO 2 within a carbon shell while maintaining a stable hollow structure. The as-prepared carbon-encapsulated SnO 2 hollow spheres after acid etching (SnO 2 @C–6H) exhibited enhanced electrochemical performance for LIBs characterized by high cycling stability and rate capacity. Specifically, SnO 2 @C–6H displayed a reversible capacity of 897.9 mA h g −1 at 200 mA g −1 after 120 cycles and a promising rate capacity of 549.8 mA h g −1 at a high current density of up to 2000 mA g −1 . The obtained high-performance could be attributed to the formation of a unique hollow structure with an enlarged specific surface area of 215.18 m 2 g −1 and a relatively high degree of graphitization (i.e., I D /I G = 0.84) of the carbon shell. A plausible cause for this performance was that the acquired hollow spheres not only provide a barrier effect for volume expansion and the aggregation of SnO 2 , but also promote lithium storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
NEW CARBON MATERIALS
·
2019
·
IF 1.387
Hai-feng Chen,Juan-juan Wu,Ming-yue Wu,Hui Jia
Copper nanoparticles encapsulated by carbon (Cu-NPs@C) were synthesized by a two-step method by mixing cupric chloride and glucose in a solution, followed by carbonization. The microstructures and antibacterial activities of the Cu-NPs@C samples were characterized by TEM, XRD, XPS, nitrogen adsorption and antibacterial activity tests. Results indicated that the as-synthesized Cu-NPs had a FCC crystal structure and a spherical morphology of diameter 4-46 nm and were well dispersed in the porous graphitic carbon layers. When the mass ratio of cupric chloride to glucose was less than 1:5, the Cu-NPs@C were of pure metallic copper without any oxides, and were stable against ambient air oxidation. The Cu-NPs@C synthesized with a mass ratio of cupric chloride to glucose of 1:5 had a specific surface area of 418 m 2 /g, which showed much higher antibacterial activities against three different common bacteria (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) than pure nano-copper powder. It was believed that the carbon layers are responsible for capturing the bacteria while the copper ions released from the copper nanoparticles kill them. The outer carbon layers effectively protected the metallic copper inside from oxidation. These findings indicate that Cu-NPs@C can be used as a stable antibacterial agent in biomedical applications.
研究领域:
材料科学
·
微生物学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 5
·1586-1597
·
IF 6.177
Shuai Wang,Nan Jiang,Tianhan Zhu,Qiang Zhang,Chunlei Zhang,Huan Wang,Yanguang Chen,Feng Li,Hua Song
Hydrodeoxygenation (HDO) of phenolic compounds is a promising technology to convert biomass materials to value-added chemicals and fuels. However, the development of highly efficient catalysts remains a great challenge. In this work, a facile one-step pyrolysis–phosphidation strategy for the synthesis of carbon-encapsulated nanostructured Ni2P@C(x) catalysts (x is the initial mass ratio of NaH2PO2 to Ni-MOF-74) under a N2 atmosphere from a metal–organic framework (Ni-MOF-74) was proposed and the prepared catalysts were used for HDO of phenol. The effects of different values of x and reaction conditions on the phenol HDO performance as well as product distribution were investigated. The results showed that as compared to the Ni@C catalyst (4.2%), the de-oxygenated product selectivity was enhanced 22.8 times by the introduction of the P species due to the promoted dehydration of cyclohexanol over Ni2P@C(x) catalysts. Ni2P@C(3) exhibited the best catalytic performance at the temperature of 250 °C, pressure of 2 MPa, and reaction time of 2 h; the conversion of phenol was 100%, and the total yield of deoxygenated products reached 100%. The HDO of phenol over the Ni2P@C(x) catalyst mainly proceeded via the HYD pathway (hydrogenation of the aromatic ring to cyclohexanol, and dehydration of cyclohexanol to give rise to cyclohexene followed by hydrogenation to cyclohexane).
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
Catalysis Science & Technology
·
2022
·Vol. 12
·期 12
·3982-3991
·
IF 6.177
Guang-Rong Ding,Yao-Feng Wang,Guo-Yi Duan,Tao Guo,Xiao-Feng Xu,Chun-Shan Li,Bao-Hua Xu
Adiponitrile (ADN) is a key intermediate for the industrial production of polyamides represented by nylon 66. In this study, the chemoselective nitrilation of dimethyl adipate (DMA) with ammonia (NH3) under continuous flow conditions was studied on carbon encapsulated oxygen-deficient WOx<3 catalysts (WOx@C/C). A combination of dispersed anchor sites at a poly(ionic liquid) (PIL) template, the porosity of active carbon support, and the calcination procedure allows the formation of effective WOx@C-600-0.25-A1, persisting high BET specific surface area and WO2.83 active phase of appropriate size. It delivers ADN and methyl 5-cyanopentanoate (MCP) with an excellent selectivity of up to 95.8% at a weight hourly space velocity of DMA (WHSVDMA) of ∼0.64 gDMA gcat−1 h−1 and an NH3/DMA molar ratio of 13 : 1. A tandem reaction route from DMA to ADN via MCP was elucidated, wherein the second nitrilation of MCP to ADN proceeds very slowly. Besides, both CDMA and TONADN/TONMCP are significantly influenced by the physical dispersion and size of the active WO2.83 phase in WOx@C/C.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Jiajin Li,Minglei Lu,Yuxin Ge,Weiwei Lu,Zidi Liu,Hongde Xu,Yu Zhang,Zhihui Li,Zhuoyu Zheng,Pengxiang Gao,Qian Zhang,Tiejun Wang
Aqueous-phase reforming of methanol (APRM) is an important method for H 2 production, widely used in energy fields like polymer electrolyte membrane fuel cells (PEMFCs). However, traditional noble metal catalysts , being expensive and vulnerable to CO poisoning, restrict their practical application. Therefore, developing robust non-noble metal catalysts for efficient and sustainable H 2 production with low CO levels in APRM at low temperatures is highly significant. In this study, a novel approach was employed to synthesize carbon-encapsulated Cu catalyst via controlled pyrolysis , leading to Cu@CA-Val catalyst with excellent low-temperature catalytic activity. The optimal Cu@CA-Val-300 catalyst exhibited a high hydrogen production rate of 0.2–27.0 μmolH 2 /g cat /s over a wide temperature of 135–180 °C (base-free), surpassing the most Cu-based and Pt-based catalysts. The Cu@CA-Val-300 catalyst exhibited exceptional hydrothermal stability during continuous operation in a fixed reactor for 200 h. Efficient H 2 production was attributed to good wettability , enabling the diffusion of CH 3 OH and H 2 O molecules into Cu + /Cu 0 sites for activation, with CO being suppressed and transformed through the formate formation.
研究领域:
能源化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Materials and Technologies
·
2025
·
IF 9.2
Yanxu Lu,Meiqing Guo,Zhuoya Zhang,Weijia Meng,Chunli Guo,Zhongchao Bai,Genwei Wang,Xiaojun Wang,Jiaye Ye
Antimony-based anodes, due to their high theoretical capacity, receive significant interest, but their further application in LIBs has been hindered by the large volumetric variation during lithiation/delithiation. To identify potential candidates with superior stability, COMSOL Multiphysics simulations are performed to analyze the voltage changes, lithium-ion concentrations, and stress distribution of solid rod, single-layer hollow tube, and dual-layer hollow tube model. It is obvious that the battery voltage changes and lithium-ion concentrations of these models are virtually the same. However, the stress distribution of the first two models presents the feature of small stress in the middle and large stress near the ends, while for the dual-layer hollow tube model, the closer to the end, the smaller the stress value is instead. In the meantime, the dual-layer hollow tube can effectively decrease the stress of the electrode more than 30 %. Herein, inspired by the theoretical prediction results, a carbon-encapsulated Sb nanotube (Sb@C) anode material is designed and fabricated by a simple hydrothermal method and subsequent treatments. Besides the alleviation of vast expansion of the Sb volume, the small pores of the encapsulated carbon layer provided more channels for Li + transport, which boosted the electrochemical performance of the Sb@C nanotube electrode. Consequently, under 0.1 A g −1 after 1000 cycles, the cell with the Sb@C nanotube anode retains the discharged capacity is 226.1 mAh g −1 with 99.7 % CE indicating good cycling stability. This study provides a fundamental insight into Sb-based electrodes and offers meaningful guidance for designing high-capacity and high-performance Sb-based nanotube anodes for lithium storage and beyond.
研究领域:
材料科学
·
电化学
✓ 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）