ACS Nano
·
2020
·
IF 14.588
Lu Guan,Han Hu,Linqing Li,Yuanyuan Pan,Yifan Zhu,Qiang Li,Hailing Guo,Kai Wang,Yunchun Huang,Mengdi Zhang,Yingchun Yan,Zhongtao Li,Xiaoling Teng,Junwei Yang,Jiazhi Xiao,Yunlong Zhang,Xiaoshan Wang,Mingbo Wu
Despite their promising potential, the real performance of lithium-sulfur batteries is still heavily impeded by the notorious shuttle behavior and sluggish conversion of polysulfides. Complex structures with multiple components have been widely employed to address these issues by virtue of their strong polarity and abundant surface catalytic sites. Nevertheless, the tedious constructing procedures and high cost of these materials make the exploration of alternative high-performance sulfur hosts increasingly important. Herein, we report an intrinsic defect-rich hierarchically porous carbon architecture with strong affinity and high conversion activity toward polysulfides even at high sulfur loading. Such an architecture can be prepared using a widely available nitrogen-containing precursor through a simple yet effective in situ templating strategy and subsequent nitrogen removal procedure. The hierarchical structure secures a high sulfur loading, while the intrinsic defects strongly anchor the active species and boost their chemical conversion because of the strong polarity and accelerated electron transfer at the defective sites. As a result, the lithium-sulfur batteries with this carbon material as the sulfur host deliver a high specific capacity of 1182 mAh g–1 at 0.5 C, excellent cycling stability with a capacity retention of 70% after 500 cycles, and outstanding rate capability, one of the best results among pure carbon hosts. The strategy suggested here may rekindle interest in exploring the potential of pure carbon materials for lithium-sulfur batteries as well as other energy storage devices.
研究领域:
材料科学
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能源存储技术
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL RESEARCH
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2024
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IF 7.7
Mingqi He,Haiqian Zhao,Jiuyang Jia,Wei Zhou,Zhonghua Wang,Kaibo An,Yiyang Jiao,Xue Yang,Xiaolong Zhang,Tianhang Fan
Porous carbon adsorption represents a critical component of CCUS technologies, with microporous structures playing an essential role in CO 2 capture. The preparation of porous carbon introduces intrinsic defects, making it essential to consider both pore size and these defects for a comprehensive understanding of the CO 2 adsorption mechanism. This study investigates the mechanisms of CO 2 adsorption influenced by intrinsic defects and pore size using multiscale methods, incorporating experimental validation, Grand Canonical Monte Carlo simulations, and Density Functional Theory simulations. Intrinsic defects increase structural disorder and microporous content in porous carbon by distorting the graphene framework, thereby creating additional spaces for CO 2 adsorption. Moreover, atomic charge redistribution induced by intrinsic defects disrupts the balance of van der Waals and electrostatic potentials, generating more active adsorption sites and enhancing the strength of CO 2 adsorption. This research aims to clarify the facilitative mechanisms of intrinsic defects and pore size on CO 2 adsorption in porous carbons and to provide a theoretical basis for designing efficient carbon-based adsorbents.
研究领域:
材料科学
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环境科学
·
计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Energy Materials
·
2020
·Vol. 10
·期 9
·1903652
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IF 25.245
Ruiqi Guo,Chunxiao Lv,Wenjia Xu,Junwei Sun,Yukun Zhu,Xianfeng Yang,Junzhi Li,Jin Sun,Lixue Zhang,Dongjiang Yang
Due to their high conductivity and low cost, carbon materials have attracted great attention in the field of energy storage, especially as anode material for sodium ion batteries. Current research focuses on introducing external defects through heteroatom engineering to improve the sodium storage performance of carbon materials. However, there is still a lack of systematic investigation of the effects of intrinsic defects prevalent in carbon materials on sodium storage performance. Herein, template-assisted method was used to design carbon materials with different degrees of intrinsic defects and explore their sodium storage properties. The experimental results show that the intrinsic defects in the carbon materials facilitates the adsorption behavior of Na + during the surface induction capacitance process. Among them, the best carbon anode material exhibits high reversible capacity (221 mAh g −1 at 1 A g −1 ) and excellent rate performance. In addition, the density functional theory calculations also show that the existence of intrinsic defects can optimize the distribution of electron density, thereby increasing the Na-adsorption capacity. This work makes an important contribution to understanding the role of intrinsic defects in the sodium storage performance of carbon materials.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Xiaozeng Miao,Xiliang Chen,Wenhao Wu,Daohui Lin,Kun Yang
Enhanced oxidation process via non-radical pathway in biochar (BC)/persulfate system is an important technology in environmental remediation because of its selectivity toward electron-rich organic compounds. The current methods are focused on heteroatom doping to improve the catalytic performance of BC, while the role of intrinsic defects remains unclear. Herein, graphitic biochar (GBC) was firstly prepared and then post annealed to tailor the degree of intrinsic defects. The annealed GBC exhibited a superior activity in the activation of peroxydisulfate (PDS) for tetracycline (TC) degradation than the pristine one. In particular, product derived at 1000 °C (GBC-1000) exhibited the highest catalytic efficiency and degradation rate, which was 2.6-fold of the pristine GBC. The contribution of free radicals ( SO 4 •− , HO•) and singlet oxygen ( 1 O 2 ) to the oxidation process were excluded by electron paramagnetic resonance and quenching test. A positive linear correlation between the pseudo first order rate constants ( k obs ) and carbon defects (I D /I G ) was established, implying the crucial role of intrinsic defects in PDS activation. The analysis of in situ Raman and linear sweep voltammetry (LSV) experiments indicated that intrinsic defects act as active sites by combining PDS molecules to form metastable surface-confined reactive species (BC-PDS*), which involved in the nonradical oxidation path. Together with chronoamperometry tests and electrochemical impedance spectroscopy, it was revealed that the catalytic mechanism of intrinsic defects in PDS activation was a BC-PDS* meditated electron transfer pathway. This study provides a new alternative method for regulating the electron transfer pathway of biochar/peroxydisulfate system.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Tao Wang,Lu Xue,Yonghong Liu,Tao Fang,Lu Zhang,Baoshan Xing
Due to their high adsorption capacity and low cost, carbon-based materials have experienced great progress in the removal of tetracyclines. Unfortunately, the nature of the adsorption site is far from clarified. Especially, it is still a great challenge to systematically explore the impact of intrinsic defects of carbon-based adsorbents on the adsorption of tetracyclines. Herein, carbon-based adsorbents with different defects were designed and prepared, and their adsorption properties of tetracyclines were systematically studied. From microscopic characterization of carbon-based adsorbents and batch adsorption experiments, the intrinsic defects of carbon-based adsorbents facilitated the adsorption performance of tetracyclines. The best adsorbent (SSG-C) had a very high adsorption capacity (526.9 mg/g for tetracycline (TTC); 360.9 mg/g for oxytetracycline (OTC)). Additionally, density functional theory simulation results show that the ring defects of sp 2 species promoted the adsorption performance more than sp 3 edge defects, and the adsorption performance increased with increasing ring defect of sp 2 species. Based on the above analysis, we proposed that intrinsic carbon defects activate the π electrons of sp 2 carbon and facilitate π-π interaction between carbon-based adsorbents and tetracyclines, particularly the ring defects of sp 2 species. This study provides a decisive contribution to better understanding of the role of intrinsic defects in carbon-based adsorbents for removal of tetracyclines.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Guojuan Qu,Peng Jia,Tao Zhang,Shuai Tang,Md. Nahid Pervez,Yixiong Pang,Bin Li,Chengjin Cao,Yaping Zhao
Doping nonmetallic heteroatoms into carbonaceous materials is a proven strategy for enhancing peroxymonosulfate (PMS) activation in the degradation of endocrine-disrupting compounds (EDCs). Understanding the role of heteroatom doping defects and intrinsic defects (topological, vacancies, or edge defects) on PMS activation is crucial for designing more efficient carbon catalysts. Herein, we synthesized nitrogen (N) and phosphorus (P) co-doped carbon microspheres (NPCs) through the pyrolysis of aminophosphonic acid resin (D418) precursors and utilized them to activate PMS for bisphenol A (BPA) degradation. The pyrolysis temperature was found to regulate the type and degree of defects, as well as the configuration of N and P. NPC-1000 (pyrolysis temperature at 1000 °C) exhibited the highest reaction rate constant ( k ) (1.20 × 10 −1 min −1 ) with the lowest N and P doping defects and the highest intrinsic defect intensity resulting from the removal of N and P during pyrolysis. Density functional theory (DFT) calculations and correlation analysis between defect sites and k suggest that the adsorption of PMS was facilitated by graphitic N-coordinated C and intrinsic defect sites rather than P doping defect sites, resulting in the degradation of BPA through electron transfer and radical mechanisms, specifically superoxide radicals (O•–2). Excess halide anions led a significant increase of k with only a limited formation of trichloromethane (TCM) (disinfection byproducts) in presence of 100 mM Cl − . This research offers fundamental insights into constructing intrinsic defects through regulating heteroatom configuration, intending to enhance the catalytic activity of metal-free materials.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 17
·5408-5417
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IF 6.177
Wenhua Li,Shule Zhang,Bo Peng,Qianqiao Chen,Qin Zhong
Typically, the more intrinsic defects of carbon materials are unfavorable to conductivity, while they are considered to be the active sites of carbon materials in the field of electrocatalysis. Therefore, seeking a balance between conductivity and active sites is the key to improve the catalytic performance of unadulterated carbon materials. Herein, the hierarchical porous carbon (HPC) prepared by the soft-templating approach is accurately adjusted via the facile hydrothermal method using H3BO3 and H3PO3 as structural modulators. The structural characterization indicates that both H3BO3 and H3PO3 reagents can drive the carbon catalyst to produce more intrinsic defects, and H3PO3 can reduce the amount of oxygen-containing groups in the carbon surface to improve conductivity. The structurally optimized HPC used as a counter electrode in polysulfide electrolytes exhibits a charge transfer resistance as low as 2.25 Ω, and the CdS/CdSe quantum dot sensitized solar cell (QDSSC) has a power conversion efficiency of 4.62%. These confirm that the reduction activity towards Sn2− ions in QDSSCs can be effectively improved by adjusting the degree of carbon defects. This report provides a new perspective on intrinsic defects for improving the electrocatalytic activity of the unadulterated carbon material.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）