CARBON
·
2025
·
IF 11.6
Han Yang,Chenxu Yang,Yibo Zhang,Qi Li,Jun Zhang,Ziyang Lu,Yue Chu,Quan-Hong Yang,Ying Tao
Defects in hard carbon are primarily associated with the slope capacity arising from sodium ion adsorption on defect sites for sodium storage. However, the impact of defects on plateau sodium storage remains poorly understood owing to the difficulties for hard carbon in precisely customizing carbon defects in the walls of closed pores without changing other structures such as pore geometry. Here, sieving carbon is selected as a model material to study the role of defects within closed pores in plateau sodium storage, considering that its pore forming and pore sealing by chemical vapor deposition are decoupled during material preparation. Specifically, vacancy-dominated defects are formed within closed pores by hydrogen reduction of porous carbon precursor and an identical external surface with deposited carbon covered is obtained by chemical vapor deposition. Such a vacancy-rich sieving carbon exhibits a high specific capacity of 470 mAh g −1 , along with an increased plateau capacity and improved cycling stability, remaining 72.3 % of its initial capacity after 400 cycles (342 mAh g −1 ). A series of spectroscopic studies demonstrate that increased carbon vacancies promote the formation of sodium clusters with higher reversibility in closed pores. This work provides new insights into the mechanism of plateau sodium storage and offers an effective strategy to improve the capacity and cycling stability of carbon anodes for sodium-ion batteries.
研究领域:
材料科学
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电化学
·
储能技术
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Kang Liu,Zibo Xu,Mengmeng Wang,Daniel S. Alessi,Yuanzhi Tang,Daniel C. W. Tsang
Resource recovery from retired electric vehicle lithium-ion batteries (LIBs) is a key to sustainable supply of technology-critical metals. However, the mainstream pyrometallurgical recycling approach requires high temperature and high energy consumption. Our study proposes a novel mechanochemical processing combined with hydrogen (H2) reduction strategy to accelerate the breakdown of ternary nickel cobalt manganese oxide (NCM) cathode materials at a significantly lower temperature (450 °C). Particle refinement, material amorphization, and internal energy storage are considered critical success factors for the accelerated decomposition of NCM cathode materials. In our proposed approach, NCM cathode materials can develop active sites with carbon defects (Cv) and oxygen vacancies (Ov), which improve the reduction and breakdown of H2. The adsorbed H2 on the surface of NCM decomposes into H* and combines with oxygen to form OH species, which can be facilitated by Ov via the enhanced charge transfer. The introduced Cv can enhance H2 cracking and generate *C–H species to promote the thermal decomposition of NCM. The presence of defects proves to foster the preferential reduction of Mn(IV) by H2, leading to a lower activation energy for the NCM decomposition (from 139 to 110 kJ/mol) with less H2 consumption. Life cycle assessment suggests a reduction of 4.42 kg CO2 eq for the recycling of every 1.0 kg of retired batteries. This study can promote material circularity and minimize the environmental burden of mining technology-critical metals for a low-carbon transition.
研究领域:
材料科学
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环境科学
·
能源工程
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Xin Yu,Zhengyi Zhao,Guofei Zhang,Sirong Li,Yanzhi Yang,Zhiyong Yan,Xin Tian,Xuechun Xiao
In this study, a one-step preparation of carbon-rich MnCo 2 O 4.5 precursors are achieved by adding glucose in a hydrothermal environment. Subsequently, MnCo 2 O 4.5 catalytic materials with different carbon defect contents are obtained by controlling the calcination temperature, which enables the simultaneous release of great heat during the thermal decomposition of catalytic AP. This specially designed MnCo 2 O 4.5 catalytic material has a hollow structure and exhibits good dispersion and a large specific surface area. The high-temperature decomposition temperature ( T HTD ) of ammonium perchlorate (AP) is reduced from 473.48 ℃ to 301.32 ℃ after adding 2 wt% catalytic materials. The catalytic materials resulte in a threefold increase in the decomposition heat release of AP (from 888.26 J·g −1 to 2616.98 J·g −1 ). It also reduced the activation energy ( E a ) by half, from 296.8 kJ·mol −1 to 146.2 kJ·mol −1 , greatly facilitating the reaction. Consequently, the reaction rate ( k ) is doubled, from 0.44 s −1 to 0.97 s −1 . The bimetallic synergistic effect of MnCo 2 O 4.5 itself, combined with the carbon material, significantly improved its performance in catalysing the thermal decomposition of AP. In addition, the combustion of carbon materials not only provides additional heat for AP pyrolysis but also further enhances the combustion of the Hydroxy Terminated Polybutadiene Composite Solid Propellant (HTPB-CSP) system. The introduction of this catalytic material reduces the CSP ignition delay time by 13 ms, allowing for a faster and more intense combustion process.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 4
·386
·
IF 3.444
Wenjing Yuan,Fuhua Zhang,Yaoyao Wu,Xiaotao Chen,Chihhsiang Fang,Chuanhao Li
Exploring a novel approach for the synthesis of oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) catalysts with inexpensive and high-activity is desirable. Herein, we report a bubble templating method to synthesize the graphene-like mesoporous carbon sheets with point defects as ORR/HER bifunctional electrocatalysts. The typical product shows excellent ORR performance including the positive onset potential (740 mV) and high diffusion-limiting current density (4.07 mA cm−2). Along with small Tafel slopes, the overpotential is determined to be about −453 and −378 mV at 10 mA cm−2in both alkaline and acidic media, which suggests a good candidate for HER reaction as well. The superior catalytic activities are derived from the abundant point defects on the mesoporous carbon sheets surface, especially the existence of pyridinic and pyrrolic nitrogen species. This study may be an alternative route to prepare the novel functional materials for the applications of ORR and HER.Keywords:bubble templating approach;carbon defect;oxygen reduction;hydrogen evolution
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 CATALYSIS A-GENERAL
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2021
·
IF 5.706
Huihuang Fang,Lijie Wu,Weikun Chen,Youzhu Yuan
Transition-metal carbides are attractive heterogeneous catalysts for the transformation of lignin-derived compounds. However, the effects of the surface carbon defect (C-defect) remain unclear due to coke deposition and exposed C terminations. Herein, we transform inert tungsten carbides (WC) into active catalysts via surficial C-etching using transition metals in the presence of H 2 . An optimized 1% Pt–WC catalyst with synergy of Pt and C-defects can perform a 78.6% conversion in the selective hydrogenolysis of guaiacol to phenol with 89.0% selectivity at 300 °C, while the intact WC only gives a 7.1% guaiacol conversion with 51.0% phenol selectivity under the same conditions. As a result, the 1% Pt–WC catalyst exhibits 19-fold higher reaction rate and 12.6-fold higher turnover frequency than those of WC. Moreover, no substantial loss of catalytic performance has been observed with 1% Pt–WC for 50 h on stream. A rational reaction pathway is accordingly proposed through in-depth characterizations.
研究领域:
化学工程
·
催化材料
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 12
·8564-8573
·
IF 3.3
Xiaoying Jiang,Yan Zhang,Feiyang Zhang,Jiashuo Tian,Liuping Zhang,Xinrui Zhao,Fengling Cui
Defect engineering has become a significant research area in recent years; however, little has been reported on the biological method for modulating the intrinsic carbon defects of the biochar framework. Herein, a fungi-enabled method for the fabrication of porous carbon/Fe3O4/Ag (PC/Fe3O4/Ag) composites was developed, and the mechanism underlying the hierarchical structure is elucidated for the first time. By regulating the cultivation process of fungi on water hyacinth biomass, a well-developed interconnected structure and carbon defects acting as potential catalytic active sites were formed. This new material with antibacterial, adsorption and photodegradation properties could be an excellent choice for treating the mixed dyestuff effluents with oils and bacteria, also guiding pore channel regulation and defect engineering in materials science. Numerical simulations were carried out to demonstrate the remarkable catalytic activity.
研究领域:
材料科学
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环境生物学
·
微生物学
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DOI
PubMed
高影响因子
Fundamental Research
·
2025
·
IF 6.3
Fengquan Li,Yuan Liu,Yan Dong,Haozhi Wang,Tongzhou Wang,Junda Lu,Wenjie Huang,Xiangqi Chen,Yuanyuan Guo,Xuerong Zheng,Yida Deng
Pt-carbon materials are identified as state-of-the-art electrocatalysts for oxygen reduction reaction (ORR). However, it is still a big challenge to reduce the usage of Pt while maintaining the high efficiency and durability of the catalysts. Herein, we report a topologicallly defective nanoparticle carbon (DPC) supported PtCo nanoparticles (PtCo NPs) catalyst (denoted as PtCo-DPC) with a low Pt loading for efficient ORR. The topological carbon defects with a low work function can serve as anchoring sites to trap and stabilize PtCo NPs for driving ORR. Meanwhile, the presence of topological carbon defects leads to the electron structure regulation and the lattice contraction for the PtCo NPs. The prepared PtCo-DPC demonstrates an increased half-wave potential (E 1/2 , 0.85 V vs. RHE) with a low Pt loading (4.74 μg Pt cm -2 ) and delivers a superior mass activity (MA) with 1.02 A mg pt -1 . Furthermore, the PtCo-DPC maintains a high stability after 100,000 cycles of accelerated durability test (ADT).
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2023
·
IF 3.8
Xiaoying Jiang,Yan Zhang,Feiyang Zhang,Fengling Cui
A new strategy about the biological way to modulate intrinsic carbon defects of the biochar framework was developed. Herein, the porous carbon/Fe3O4/Ag (PC/Fe3O4/Ag) composites are first prepared using a novel fungi-enabled method, and the mechanism underlying their excellent catalytic and adsorption properties was elucidated. Customization of microstructures and introducing defects in the carbon-based nanomaterial can be achieved through regulation of the fungus growth process on biomass, thereby improving the catalytic performance greatly. This work also opened a new area in materials science based on fungi-enabled defect engineering and pore channel regulation, providing unique insights into environment treatment. Theoretical calculations and simulations were carried out to understand the remarkable catalytic and adsorption performance.
研究领域:
环境科学
·
材料科学
·
生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Chang Liu,Guijuan Wei,Honglei Chen,Weiqiang Sun,Xixia Zhao,Xin Zhao
Charge redistribution strategy driven by geometry regulation of metal cores or carbon defect engineering is an effective approach to optimize the electronic structure of traditional carbon, which can boost hydrogen evolution reaction (HER) activity to inert carbon. The synergistic effect of these two methods is anticipated to more effectively manipulate the charge distribution of carbon materials. Herein, a facile low-temperature methane plasma strategy is developed, from which highly dispersive hexagonal close-packed (hcp) NiPt alloy encapsulated in the defect-rich carbon shell grown on the Ni foam (C@hcp-NiPt/NF) can be fabricated. The optimized C@hcp-NiPt/NF displays low overpotentials of 60, 110, and 60 mV at 100 mA cm −2 in 1.0 M KOH, 1.0 M PBS, and 0.5 M H 2 SO 4 , respectively. Furthermore, it demonstrates exceptional stability under alkaline, neutral and acidic conditions. Raman spectroscopy, in-situ electrochemical impedance spectroscopy (EIS), combined with theoretical calculations have unequivocally validate that the incorporation of carbon defects and the regulation of geometric structure in NiPt cores significantly augment the charge density on the carbon shell, thereby optimizing the binding affinity of carbon with H 2 O and hydrogen, ultimately resulting in improved HER performance.
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
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Jianmin Wang,Ruoyu Huang,Haitao Huang,Haijin Li,Zhijie Chen,Jiajia Cai,Hao Zhang,Yongtao Li,Xiaofang Liu,Xiaolong Deng
Developing effective strategies to improve the electrocatalytic activity of carbon-based materials is significant for Zn-air batteries (ZABs). Herein, nitrogen-doped carbon with abundant sp3-hybridized carbon defects (NC-CTS) were synthesized through a nonthermodynamic equilibrium carbonization process called carbon thermal shock (CTS). The NC-CTS catalyst exhibited a superior oxygen reduction reaction (ORR) activity with a half-wave potential of 0.81 V vs RHE and good stability in alkaline electrolyte, exceeding the NC-Furnace catalyst, which was fabricated by a thermodynamic equilibrium process. The better ORR performance originated from the increased density of sp3-hybridized carbon defects as the active sites and the optimized adsorption energy of intermediate species. The sp3-hybridized carbon defects were attributed to the obstruction of atom mobility and aggregation due to the ultrashort duration time of CTS. Furthermore, the ZABs using NC-CTS catalysts as the cathode showed good discharge performance and high cycling stability with a power density of 110 mW cm–2. This study demonstrated an effective strategy to modulate the ratio of sp3/sp2 of carbon-based electrocatalysts for the development of advanced carbon-based electrocatalysts to enhance the ORR performance and for the development of ZABs.
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
·
2025
·
IF 13.2
Faze Chen,Zilian Liu,Rongrong Miao,Huajing Zhou,Liang He,Sheng Liang,Xin Lei,Qingqing Guan
Direct oxidation of organic pollutants by visible-light-generated holes is considered a promising technique for remediating contaminated water bodies. However, random and rapid recombination of photogenerated holes and electrons hampers the accumulation of holes on catalyst surface. To address this challenge, a strategy involving the co-etching of bagasse pith parenchyma cells with iron and nitrogen was proposed, creating an Fe-N-C catalyst with a web-like fibrous structure and abundant carbon defects. This iron and nitrogen co-etching strategy endowed the Fe-N-C catalyst with not only ultrafast photogenerated electron transfer and capture capabilities but also enabled it to have abundant and accessible surface-active sites, co-facilitating rapid and efficient electron transfer between pollutants and holes. Thus, compared to pure bagasse pith carbon or nitrogen-doped carbon, the optimized Fe-N-C single-atom catalysts (SACs) exhibited a significant enhancement in the photocatalytic oxidation kinetics of tetracycline (TC) by 16.47 and 5.38 times, respectively, with the maximum degradation efficiency increasing from 25.6% and 48.6% to 99.6%. Based on theoretical and experimental analyses, the toxicity of TC-contaminated water was significantly reduced after treatment with the Fe-N-C catalyst. Through analyzing the material characterization and photocatalytic behavior, a structure-performance correlation that links intrinsic carbon defects to effective surface hole transfer in Fe-N-C was established and validated. From the perspective of holes as the primary active sites, this work offered a promising approach to enhancing the overall photocatalytic oxidation efficiency of Fe-N-C SACs.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 3
·669-678
·
IF 3.186
Niu Ling,Du Jianmei,Jiang Daochuan,Du Haiwei,Lin Xiangang,Xu Jiahui,Li Zhongjun,Zhu Chuhong,Gu Lina,Bi Hong,Yuan Yupeng
Carbon defects in graphitic carbon nitride (g-CN) can modulate the electronic structure for efficient separation of electron–hole pairs, and thereby potentially enhance the photocatalytic H 2 generation. However, the mechanism on the separation of electrons and holes in C defect-modified g-CN still remains unclear. Here we report an autogenic ammonia gas route via in-situ urea decomposition to create carbon defects in g-CN for realizing increased photocatalytic H 2 generation rate of 36.62 µmol h −1 under visible light exposure, which is 10 times higher than that of g-CN obtained in the absence of autogenic ammonia gas (~ 3.63 µmol h −1 ). Illustrated by the density functional theory calculations, the C defects can not only reduce the band gap for increased light harvesting, but also delocalize the π electrons in valence band (VB) and conduction band (CB) for efficient charge transfer. Such delocalization of π electrons facilitates the efficient separation of electrons in LUMO and holes in HOMO, then promoting the photocatalytic H 2 generation. Therefore, the creation of C defects can be used as an effective route to delocalize the π electrons in g-CN for efficient photocatalytic H 2 generation. Graphical Abstract
研究领域:
材料科学
·
物理化学
✓ 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）