JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Peng Zhao,Boxiong Shen,Guofei Shi,Jiancheng Yang,Fengju Lu,Qiqi Shi,Dongrui Kang,Chenguang Zhang
Zinc-ion batteries are receiving interest due to their high level of safety and eco-friendliness. However, the sluggish diffusion kinetics of zinc ions in the electrode limit its practical application. In this paper, rapid Zn 2+ diffusion in the MoS 2−X @NCNTs cathode is achieved by utilizing the S vacancies generated under a H 2 /Ar atmosphere and N-doped carbon nanotubes (NCNTs) derived from the pyrolysis of polyethylene and melamine. The presence of S vacancies significantly reduces the diffusion barrier of Zn 2+ , thereby promoting the transport of Zn 2+ ions. MoS 2−X @NCNTs cathode demonstrates an impressive discharge specific capacity of 220 mAh g −1 (0.1 A g −1 ) and a remarkable reversible capacity of 173 mAh g −1 (3 A g −1 ). Furthermore, the reduced adsorption energy of MoS 2−X nanosheets leads to Zn 2+ tending to preferentially insert S vacancies, resulting in a larger capacity than pure MoS 2 . This work realizes efficient storage of Zn 2+ in 2D disulfides through carbon frameworks and S vacancies. In addition, flexible zinc batteries with MoS 2−X @NCNTs cathodes have promising applications in wearable devices .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Zhongwei Wang,Xiangqian Chen,Xinlin Xie,Shuangxia Yang,Laizhi Sun,Tianjin Li,Lei Chen,Dongliang Hua
The utilization of lignin to produce high value-added chemicals remains a significant challenge, this study reports the synthesis of highly active nitrogen-doped carbon nanotubes to support nickel-based catalysts via a two-stage pyrolysis process using a mixture of melamine and nickel acetate. The catalyst morphology is controlled through the use of melamine, the doped pyridinic nitrogen serves as an anchoring site for Ni metal, facilitating the dispersion of Ni metal and the formed Ni-Nx bond enhanced the stability of the catalyst. Additionally, the electron transfer between Ni and N atoms promoting the activation of hydrogen on the metallic nickel surface, which together with the aforementioned factors, contributes to the cleavage of the C-O bond in lignin, with 23.1% monomer yield under mild conditions. The density functional theory (DFT) calculations reveal that doped nitrogen atoms can provide electrons to carbon atoms, resulting in an electron-rich state that facilitated the adsorption of hydrogen.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Kunpeng Song,Guanghui Li,Junchen Yu,Tianyue Zheng,Jingyu Wang
Efficient methods for preparing carbon nanotube (CNT)-confined metal catalysts are of great significance for electrocatalysis. Hence, in this study, Fe and Co promoters were added to the precursors of commercial carbon black and melamine to form N -doped CNTs confined bimetallic catalysts (FeCo@ N -CNTs) via in situ pyrolysis. The FeCo@ N -CNT catalysts exhibited a bamboo-like morphology with FeCo alloy nanoparticles encapsulated in the CNTs and high activity toward the oxygen reduction reaction, with a half-wave potential of 0.864 mV, higher than that of commercial Pt/C (0.827 mV) in alkaline solutions. The catalytic performance is attributable to the synergistic effects between the FeCo alloy and N -doped CNT structure. Moreover, the confinement of the FeCo nanoparticles inside the CNTs imparted the prepared catalysts with resistance to methanol poisoning and long-term stability. This versatile method of synthesizing CNTs directly from carbon black provides a new strategy for preparing high-performance non-precious-metal-based N -doped CNT catalysts for practical fuel cell applications.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Xiaoming Yu,Weixin Chen,Junjie Cai,Xia Lu,Zhipeng Sun
A modified separator for improving the electrochemical performance in Li-S batteries is fabricated by functional composites coating, comprised of MnO nanoflakes with rich oxygen vacancies and N doped carbon nanotubes (MnO-OVs/NCNTs). On the one hand, MnO as a polar material can anchor lithium polysulfides (LiPSs) on the interface via chemical bonding. In addition, introducing oxygen vacancies into MnO by heat treatment under a reducing atmosphere can regulate the electronic structure and provide extra active sites for further boosting the chemical adsorption capability of LiPSs, facilitating the redox reaction of LiPSs, as well as enhancing the electron transfer efficiency. On the other hand, the MnO-OVs/NCNTs layer is a barrier to block the LiPSs directly diffusing through the separator and acts as an upper collector to reduce the interface resistance reactivate the trapped sulfur species, thereby enhancing the sulfur utilization. Given these advantages, the MnO-OVs/NCNTs modified separator employed in Li-S batteries exhibit considerable capacity (1516 mAh g −1 at 0.1C), enhanced long-term cycling stability (capacity retention of 618 mAh g −1 for over 500 cycles at 1C), and rate performance (550 mAh g −1 at 3C).
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CARBON
·
2019
·
IF 7.466
Ruqun Guan,Lingyan Jing,Xiaoming Zhang,Shuai Chen,Nan Xue,Hengquan Yang
Carbon nanotube assemblies with controlled morphology and tailored architecture offer great potentials for myriad applications, but strategies for their production have remained a significant challenge. Here, we proposed a novel and simple microconfined-annealing strategy, in which a Pickering microdroplet patterned method and unique pyrolysis-stimulated-transformation processes were coupled unprecedentedly, for the fabrication of spherical nitrogen-doped carbon nanotube assemblies (NCNTA). Based on this strategy, the as-prepared superstructures not only retained the micrometer-size and well-defined morphology of the initial Pickering droplets, but also derived a hierarchical pomegranate-like structure where numerous interconnected NCNT particles were encapsulated by a carbon crust. More importantly, the interior architectures were shown to be manipulated through controlling synthesized parameters. Owing to the unique structure and composition of these assemblies, the yielded superstructures exhibited excellent performance and good recyclability in heterogeneous catalysis applications. This synthetic strategy provides new routes to access other micro- or macroscopic materials with novel structures and paves the way to expand their potential applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Yan Zhang,Yang Tan,Xiuxiu Wang,Liang Dong,Aihua Liu
Nickel oxide and nickel phosphide supported by nitrogen-doped multi-walled carbon nanotubes (NiO-Ni 12 P 5 /NCNTs) nanocomposites were reported as non-noble metal hybrid electrocatalysts for hydrogen evolution reaction (HER). First, an amorphous nickel phosphorous coating was facilely formed on the surface of pristine CNTs (aNi-P/CNTs) through a simplified electroless deposition without the pretreatment steps of purification, sensitization and activation. Then, aNi-P/CNTs were heated with melamine at 600 °C for 1 h under an Ar atmosphere to prepare NiO-Ni 12 P 5 /NCNTs. The as-fabricated NiO-Ni 12 P 5 /NCNTs electrocatalysts showed high HER electrocatalytic activity of -0.17 V at 10 mA cm −2 , a Tafel slope of 75 mV dec -1 and a high exchange current density of 0.049 mA cm -2 . Moreover, the NiO-Ni 12 P 5 /NCNTs electrocatalysts showed a much higher durability than Pt/C after the accelerated durability tests in 0.1 M KOH. The NiO-Ni 12 P 5 /NCNTs electrocatalysts displayed good activity and stability for HER, which may originate from the synergistic effect between the Ni compound and NCNTs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Nano Research
·
2024
·
IF 9.5
Li Jing,Jing Chuanyong,Wang Jin
Electrocatalytic CO 2 reduction to CH 4 remains challenging due to multi-electron transfer and intermediates adsorption. Herein, we synthesized electrocatalysts by growing Ni-Cu alloy structure on nitrogen-doped carbon nanotubes (Ni x Cu y -NCNT) for electrocatalytic CO 2 reduction reaction (CO 2 RR) via hydrothermal method followed by pyrolysis. The optimized Ni 1 Cu 1 -NCNT demonstrated a superior CO 2 RR performance, achieving 99.7% \(\text{FE}_{\text{CH}_{4}}\) (FE = Faradaic efficiency) and 11.54 mA • cm −2 current density at −1.2 V vs. reversible hydrogen electrode (RHE), which outperformed single metal counterparts. Its outstanding performance was due to the electrons transferred from Cu to Ni and Ni-Cu alloy shifted the d-band center toward the Fermi level, which was more conducive to the intermediate formation. In situ electrochemical attenuated total reflection (EC-ATR) and density functional theory (DFT) calculations revealed the appearance of *CHO intermediate and the pathway during the CO 2 RR process. The design of the bimetallic electrocatalyst in this study provides a new perspective for the highly selective reduction of CO 2 .
研究领域:
材料科学
·
电化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2025
·
IF 7.2
Yong Jiang,Qiang Wang,Yaping Du
It is crucial to design highly active, durable, and low precious metal mass-loaded hydrolysis ionization catalysts to promote slow water dissociation for hydrogen production. Herein, a series of armor-like catalyst heterogeneous structures of rare earth (RE) oxide/alloy confined within carbon nanotubes (RuCo/CeO 2 -NCNTs) was prepared using a one-step pyrolysis phase separation strategy. The prepared catalysts need only overpotentials of 12 and 51 mV for hydrogen evolution reaction (HER) and 141 and 192 mV for oxygen evolution reaction (OER) to achieve a current density of 10 mA/cm 2 in 1.0 mol/L KOH and 0.5 mol/L H 2 SO 4 electrolytes. Under alkaline conditions, both HER and OER can work steadily for 1000 h. The turnover frequency (TOF) values of HER and OER are 33.08 s –1 (@100 mV) and 12.75 s –1 (@300 mV) in alkaline environments, respectively. The in situ electrochemical impedance spectroscopy (EIS) test results further confirm that the introduction of cerium oxide optimizes the mass transfer process during the electrochemical process and enhances catalytic activity. The synergistic effect of the RuCo and CeO 2 heterostructure confined within NCNTs, combined with the increased conductivity resulting from the expansion of the conductive channels, accelerates reaction kinetics and enhances performance. This study also demonstrates the confinement of RE oxide heterostructures within NCNTs, providing a new solution for the development of novel RE-based catalysts and the high-value utilization of RE.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·
IF 2.93
Pei Song,Xiangjie Bo,Anaclet Nsabimana,Liping Guo
Novel phosphorus-doped polypyrrole functionalized nitrogenous carbon nanotubes (P/NCNTs) was developed for the first time as metal-free electrocatalyst for enhancing the oxygen reduction reaction (ORR) activity in alkaline medium . The P/NCNTs was successfully synthesized by pyrolyzing PPy and triphenylphosphane (TPP) under N 2 , using pyrrole as carbon and nitrogen precursors, TPP as phosphorus precursor. Various characterizations such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectra , Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) reveal that the P/NCNTs material has covalently bound P atoms with carbon framework, which can introduce defect sites and can induce uneven charge distribution . Moreover, the content of pyridine N increased after P-doping, which is of great significance in improving the ORR activity. The electrochemical behavior of the resultant material shows that the P/NCNTs has much enhanced electroactivity and better stability for ORR. Additionally, a direct four-electron pathway occurred efficiently on P/NCNTs modified electrode . These enhanced performances indicate that P/NCNTs catalyst may be an excellent cathode catalyst for ORR.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Min Ji,Siqi Niu,Yunchen Du,Bo Song,Ping Xu
Molybdenum carbide materials are considered to be promising hydrogen evolution reaction (HER) electrocatalysts due to their similar electronic structures and catalytic activities to Pt-based catalysts. Here, we report a facile synthesis of β-Mo2C nanoparticles supported on nitrogen-doped carbon nanotubes (Mo2C/N–C) through a one-step carbonization of Mo-containing anion-doped polyaniline nanotubes. It has been revealed that the size of the obtained Mo2C nanoparticles can be effectively tuned by applying different Mo-containing anions. With MoO42– from Na2MoO4, the as-prepared Mo2C/N–C(S) with ultrasmall (2–3 nm) Mo2C nanoparticles shows excellent electrocatalytic HER activity in acidic media, with an overpotential of 189 mV vs reversible hydrogen electrode (RHE) at a geometric current density of −10 mA cm–2 and a Tafel slope of 58 mV dec–1. This study opens up a new avenue for the size-controllable synthesis of transition metal carbide nanoparticles loaded on carbon supports for energy conversion applications.
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 Materials Chemistry A
·
2015
·Vol. 3
·期 43
·21451-21459
·
IF 7.443
Jianbing Zhu,Meiling Xiao,Changpeng Liu,Junjie Ge,Jean St-Pierre,Wei Xing
Non-platinum (NP) electrocatalysts with high activity and durability for oxygen reduction reactions (ORR) are required for fuel cells and other renewable systems. To avoid trial-and-error methods and achieve the rational design and synthesis of efficient NP catalysts, in-depth knowledge of the formation/growth mechanism of nanocatalysts and the origin of active sites is highly desirable. Here, we report a new class of NP catalysts with a novel structure of Fe3C encapsulated in N-doped carbon nanotubes/C. We study the formation mechanism of the nanostructure to pave the way for controlled fabrication of high-performance NP catalysts. The encapsulation of iron into carbon occurs during the first step of CNT growth and the surface functional groups on carbon black are identified as being essential for forming CNTs. The catalyst shows ultrahigh catalytic performance in both acid and alkaline media. We also examine the structure–performance dependency. The catalytic performance is highly dependent on the nanostructure and the encapsulation of Fe3C. Fe affects the catalytic performance through electronic effects rather than by directly participating in the active sites. This result is confirmed by DFT calculations, which show an increase in the density of states and a reduction in the local work function, XPS studies, and electrochemical measurements. The likelihood of N participating in the active sites is low because the catalytic performance does not depend on pyridinic and graphitic N.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Peng Wang,Fengtao Zhang,Cailing Wu,Jianji Wang,Buxing Han,Zhimin Liu
Herein, we report CoCO3-coated nitrogen-doped carbon nanotubes (NCNTs) with a sea cucumber-like morphology for water splitting. The sample with a CoCO3 content of 26.8 wt % (CoCO3/NCNT-1) exhibits excellent performance for the hydrogen evolution reaction in 1.0 M KOH electrolyte with an overpotential of 58 mV to reach 10 mA cm–2, better than the most non-noble metal catalysts reported; meanwhile, it exhibits superior electrocatalytic activity for the oxygen evolution reaction. The excellent performance of the catalyst is attributed to the nanotip effect caused by the sea-cucumber-like morphology. Notably, CoCO3/NCNT-1 can attain turnover frequencies of 2.7 s–1 at an overpotential of 50 mV, higher than that of Pt/C (1.5 s–1). A cell constructed using CoCO3/NCNT-1 as the catalyst of the electrode pair needs a low cell voltage of 1.54 V at 10 mA cm–2, superior to most reported cells. In addition, CoCO3/NCNT-1 can maintain 10 mA cm–2 for overall water splitting for 100 h without activity loss.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）