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Preparation and lithium storage performances of g-C

Zhengxu BIAN, Zehua TANG, Jinfeng XIE, Junhao ZHANG, Xingmei GUO, Yuanjun LIU, Aihua YUAN, Feng ZHANG, Qinghong KONG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 759-766 doi: 10.1007/s11708-020-0810-0

摘要: As the anode material of lithium-ion battery, silicon-based materials have a high theoretical capacity, but their volume changes greatly in the charging and discharging process. To ameliorate the volume expansion issue of silicon-based anode materials, g-C N /Si nanocomposites are prepared by using the magnesium thermal reduction technique. It is well known that g-C N /Si nanocomposites can not only improve the electronic transmission ability, but also ameliorate the physical properties of the material for adapting the stress and strain caused by the volume expansion of silicon in the lithiation and delithiation process. When g-C N /Si electrode is evaluated, the initial discharge capacity of g-C N /Si nanocomposites is as high as 1033.3 mAh/g at 0.1 A/g, and its reversible capacity is maintained at 548 mAh/g after 400 cycles. Meanwhile, the improved rate capability is achieved with a relatively high reversible specific capacity of 218 mAh/g at 2.0 A/g. The superior lithium storage performances benefit from the unique g-C N /Si nanostructure, which improves electroconductivity, reduces volume expansion, and accelerates lithium-ion transmission compared to pure silicon.

关键词: magnesium thermal reduction     g-C3N4/Si nanocomposites     volume expansion     electroconductivity     lithium-ion battery    

Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic activity

《化学科学与工程前沿(英文)》 2023年 第17卷 第1期   页码 93-101 doi: 10.1007/s11705-022-2175-x

摘要: Defect construction and heteroatom doping are effective strategies for improving photocatalytic activity of carbon nitride (g-C3N4). In this work, N defects were successfully prepared via cold plasma. High-energy electrons generated by plasma can produce N defects and embed sulfur atoms into g-C3N4. The N defects obviously promoted photocatalytic degradation performance that was 7.5 times higher than that of pure g-C3N4. The concentration of N defects can be tuned by different power and time of plasma. With the increase in N defects, the photocatalytic activity showed a volcanic trend. The g-C3N4 with moderate concentration of N defects exhibited the highest photocatalytic activity. S-doped g-C3N4 exhibited 11.25 times higher photocatalytic activity than pure g-C3N4. It provided extra active sites for photocatalytic reaction and improved stability of N defects. The N vacancy-enriched and S-doped g-C3N4 are beneficial for widening absorption edge and improving the separation efficiency of electron and holes.

关键词: g-C3N4     nitrogen defect     sulfur doping     photodegradation     plasma    

g-CN-coated MnO hollow nanorod cathode for stable aqueous Zn-ion batteries

《化学科学与工程前沿(英文)》 2023年 第17卷 第2期   页码 217-225 doi: 10.1007/s11705-022-2214-7

摘要: Aqueous zinc-ion batteries are attracting considerable attention because of their high safety compared with conventional lithium-ion batteries. Manganese-based materials have been widely developed for zinc-ion batteries cathode owning to their low cost, high security and simple preparation. However, the severe volume expansion and poor stability during charging and discharging limit the further development of manganese-based cathodes. Herein, superior α-MnO2@g-C3N4 was successfully prepared for stable zinc-ion batteries (ZIBs) cathode by introducing g-C3N4 nanosheets. Compared with pure α-MnO2, α-MnO2@g-C3N4 has a specific capacity of 298 mAh·g–1 at 0.1 A·g–1. Even at 1 A·g–1, the α-MnO2@g-C3N4 still retains 100 mAh·g–1 (83.4% retention after 5000 cycles), implying its excellent cycling stability. The α-MnO2@g-C3N4-based cathode has the highest energy density (563 Wh·kg–1) and power energy density (2170 W·kg–1). This work provides new avenues for the development of a wider range of cathode materials for ZIBs.

关键词: α-MnO2 hollow nanorods     g-C3N4     heterojunction     aqueous Zn-ion batteries    

结构功能一体化的高性能陶瓷材料的研究与开发

江东亮

《中国工程科学》 2003年 第5卷 第2期   页码 35-39

摘要: 复合化、低成本制备等要求出发, 并就现有高性能陶瓷材料的基本性能和材料制备工艺上的优缺点进行了分析;简要介绍了碳化硅(SiC)陶瓷、 添加Nd的钇铝石榴子石(Nd-YAG)陶瓷、掺有稀土的氮化硅(RE-Si3N4)陶瓷等几种具有结构和功能一体化高性能陶瓷材料的优良性能,可能的应用以及目前存在的问题,特别是在基础研究和制备科学上今后应予以关注的方面。

关键词: 结构和功能一体化     高性能陶瓷     碳化硅     Nd-YAG     RE-Si3N4    

Performance of iron-air battery with iron nanoparticle-encapsulated CN composite electrode

《能源前沿(英文)》 doi: 10.1007/s11708-023-0913-5

摘要: Highly efficient and stable iron electrodes are of great significant to the development of iron-air battery (IAB). In this paper, iron nanoparticle-encapsulated C–N composite (NanoFe@CN) was synthesized by pyrolysis using polyaniline as the C–N source. Electrochemical performance of the NanoFe@CN in different electrolytes (alkaline, neutral, and quasi-neutral) was investigated via cyclic voltammetry (CV). The IAB was assembled with NanoFe@CN as the anode and IrO2 + Pt/C as the cathode. The effects of different discharging/charging current densities and electrolytes on the battery performance were also studied. Neutral K2SO4 electrolyte can effectively suppress the passivation of iron electrode, and the battery showed a good cycling stability during 180 charging/discharging cycles. Compared to the pure nano-iron (NanoFe) battery, the NanoFe@CN battery has a more stable cycling stability either in KOH or NH4Cl + KCl electrolyte.

关键词: energy storage and conversion     metallic composites     nanocomposites     iron-air battery     iron anode    

GO-modified flexible polymer nanocomposites fabricated via 3D stereolithography

Chi Him Alpha Tsang, Adilet Zhakeyev, Dennis Y.C. Leung, Jin Xuan

《化学科学与工程前沿(英文)》 2019年 第13卷 第4期   页码 736-743 doi: 10.1007/s11705-019-1836-x

摘要: Graphene oxide (GO) induced enhancement of elastomer properties showed a great deal of potential in recent years, but it is still limited by the barrier of the complicated synthesis processes. Stereolithography (SLA), used in fabrication of thermosets and very recently in “flexible” polymers with elastomeric properties, presents itself as simple and user-friendly method for integration of GO into elastomers. In this work, it was first time demonstrated that GO loadings can be incorporated into commercial flexible photopolymer resins to successfully fabricate GO/elastomer nanocomposites via readily accessible, consumer-oriented SLA printer. The material properties of the resulting polymer was characterized and tested. The mechanical strength, stiffness, and the elongation of the resulting polymer decreased with the addition of GO. The thermal properties were also adversely affected upon the increase in the GO content based on differential scanning calorimetry and thermogravimetric analysis results. It was proposed that the GO agglomerates within the 3D printed composites, can result in significant change in both mechanical and thermal properties of the resulting nanocomposites. This study demonstrated the possibility for the development of the GO/elastomer nanocomposites after the optimization of the GO/“flexible” photoreactive resin formulation for SLA with suitable annealing process of the composite in future.

关键词: graphene oxide     polymer     flexible     3D printing     stereolithography    

Recent advances in special morphologic photocatalysts for NO removal

《环境科学与工程前沿(英文)》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1573-0

摘要:

● Systematic information of recent progress in photocatalytic NO x removal is provided.

关键词: NOx removal     Photocatalyst     Graphene     C3N4     Bi-based compounds.    

Pd/Fe3O4 supported on bio-waste derived cellulosic-carbon as a nanocatalyst for CC coupling and electrocatalytic

《化学科学与工程前沿(英文)》 2022年 第16卷 第10期   页码 1514-1525 doi: 10.1007/s11705-022-2158-y

摘要: The current work describes the synthesis of a new bio-waste derived cellulosic-carbon supported-palladium nanoparticles enriched magnetic nanocatalyst (Pd/Fe3O4@C) using a simple multi-step process under aerobic conditions. Under mild reaction conditions, the Pd/Fe3O4@C magnetic nanocatalyst demonstrated excellent catalytic activity in the Hiyama cross-coupling reaction for a variety of substrates. Also, the Pd/Fe3O4@C magnetic nanocatalyst exhibited excellent catalytic activity up to five recycles without significant catalytic activity loss in the Hiyama cross-coupling reaction. Also, we explored the use of Pd/Fe3O4@C magnetic nanocatalyst as an electrocatalyst for hydrogen evolution reaction. Interestingly, the Pd/Fe3O4@C magnetic nanocatalyst exhibited better electrochemical activity compared to bare carbon and magnetite (Fe3O4 nanoparticles) with an overpotential of 293 mV at a current density of 10 mA·cm–2.

关键词: bio-waste     cellulosic-carbon     Pd/Fe3O4     Hiyama cross-coupling     hydrogen evolution reaction     recyclability    

Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要: Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词: Rh2O3     CePO4     N2O decomposition    

Novel mutation c.1210-3C>G in with a poly-T tract of 5T affects mRNA splicing in a Chinese patient

《医学前沿(英文)》 2022年 第16卷 第1期   页码 150-155 doi: 10.1007/s11684-021-0846-5

摘要: Cystic fibrosis (CF) is a rare autosomal recessive disease with only one pathogenic gene cystic fibrosis transmembrane conductance regulator (CFTR). To identify the potential pathogenic mutations in a Chinese patient with CF, we conducted Sanger sequencing on the genomic DNA of the patient and his parents and detected all 27 coding exons of CFTR and their flanking intronic regions. The patient is a compound heterozygote of c.2909G>A, p.Gly970Asp in exon 18 and c.1210-3C>G in cis with a poly-T of 5T (T5) sequence, 3 bp upstream in intron 9. The splicing effect of c.1210-3C>G was verified via minigene assay in vitro, indicating that wild-type plasmid containing c.1210-3C together with T7 sequence produced a normal transcript and partial exon 10-skipping-transcript, whereas mutant plasmid containing c.1210-3G in cis with T5 sequence caused almost all mRNA to skip exon 10. Overall, c.1210-3C>G, the newly identified pathogenic mutation in our patient, in combination with T5 sequence in cis, affects the CFTR gene splicing and produces nearly no normal transcript in vitro. Moreover, this patient carries a p.Gly970Asp mutation, thus confirming the high-frequency of this mutation in Chinese patients with CF.

关键词: cystic fibrosis     CFTR     splicing mutation     minigene    

NiCo2O4@quinone-rich NC core–shell nanowires as composite electrode for electric double layer capacitor

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 373-386 doi: 10.1007/s11705-022-2223-6

摘要: The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo2O4 nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo2O4 nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF∙cm–2 at the current density of 1 mA∙cm–2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW∙h∙cm–3 at a power density of 180 mW∙cm–3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA∙cm–2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.

关键词: carbon cloth     NiCo2O4 nanowires     core−shell structure     quinone-rich     electric double layer capacitor    

Effect of noble metal nanoparticle size on CN bond cleavage performance in hydrodenitrogenation: a study

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1986-2000 doi: 10.1007/s11705-023-2337-5

摘要: Breakage of the C–N bond is a structure sensitive process, and the catalyst size significantly affects its activity. On the active metal nanoparticle scale, the role of catalyst size in C–N bond cleavage has not been clearly elucidated. So, Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature, and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o-propylaniline with different C–N bond hybridization patterns as reactants. Results showed a 13 times higher reaction rate for sp3-hybridized C–N bond cleavage than sp2-hybridized C–N bond cleavage, while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size increased. Different concentrations of terrace, step, and corner sites were found in different sizes of Ru nanoparticles. The relationship between catalytic site variation and C–N bond cleavage activity was further investigated by calculating the turnover frequency values for each site. This analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C–N bond cleavage activity, and the step atoms are the active sites for the C–N bond cleavage. When Ru nanoparticles are smaller than 1.9 nm, they have a strong adsorption effect on the reactants, which will affect the catalytic performance of the Ru catalyst. Furthermore, these findings were also confirmed on other metallic Pd/Pt catalysts. The role of step sites in C–N bond cleavage was proposed using the density function theory calculations. The reactants have stronger adsorption energies on the step atoms, and step atoms have d-band center nearer to the Fermi level. In this case, the interaction with the reactant is stronger, which is beneficial for activating the C–N bond of the reactant.

关键词: sp3/sp2-hybridized C–N bond     noble metal nanoparticle     catalytic active site     turnover frequency     DFT    

过硫酸盐诱导的缺陷氮化碳中三配位氮(N3C)空位增强光催化产过氧化氢 Article

缪蔚, 王奕杰, 刘莹, 秦贺贺, 褚成成, 毛舜

《工程(英文)》 2023年 第25卷 第6期   页码 214-221 doi: 10.1016/j.eng.2021.12.016

摘要: 其中石墨氮化碳(g-C3N4)被认为是最有前途的合成过氧化氢的光催化剂之一;并且,在g-C3N4中引入氮空位已被证明是提高其光催化活性的有效策略在此,本文提出了一种简便的过硫酸钠共晶聚合方法,制备了具有丰富三配位氮空位(N3C)的g-C3N4。这种类型的氮空位在g-C3N4光催化产过氧化氢的研究中尚未得到重视。富含N3C空位的g-C3N4的光催化过氧化氢产量是原始g-C3N4的4.5倍。本研究提出了在g-C3N4中引入N3C空位的新策略,为开发光催化产过氧化氢的活性催化剂提供了一种新方法。

关键词: 氮化碳     N3C空位     过氧化氢     光催化     过硫酸盐    

一种用于用户端设备且工作在2G/3G/4G/IMT/5G频段的小型化超宽带交叉振子天线 Correspondences

郭景丽1,崔伦1,刘英1,孙保华1,李肖锋2

《信息与电子工程前沿(英文)》 2022年 第23卷 第2期   页码 339-345 doi: 10.1631/FITEE.2000456

摘要: 设计了一种用于用户端设备(CPE)且工作在2G/3G/4G/IMT/5G频段的小型化超宽带交叉振子天线。此外,通过在交叉振子下方增加开缝的寄生贴片,天线整体的带宽能够扩展到5G sub-6 GHz频段。此外,对天线结构进行了加工和测试。

关键词: 5G;交叉振子;双极化天线;终端天线;超宽带    

Adsorption characteristics of ciprofloxacin onto g-MoS2 coated biochar nanocomposites

Zhenyu Yang, Rong Xing, Wenjun Zhou, Lizhong Zhu

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-019-1218-0

摘要: The g-MoS2 coated composites (g-MoS2-BC) were synthesized. The coated g-MoS2 greatly increased the adsorption ability of biochar. The synergistic effect was observed for CIP adsorption on g-MoS2-RC700. The adsorption mechanisms of CIP on g-MoS2-BC were proposed. The g-MoS2 coated biochar (g-MoS2-BC) composites were synthesized by coating original biochar with g-MoS2 nanosheets at 300°C(BC300)/700°C (BC700). The adsorption properties of the g-MoS2-BC composites for ciprofloxacin (CIP) were investigated with an aim to exploit its high efficiency toward soil amendment. The specific surface area and the pore structures of biochar coated g-MoS2 nanosheets were significantly increased. The g-MoS2-BC composites provided more π electrons, which was favorable in enhancing the π-π electron donor-acceptor (EDA) interactions between CIP and biochar. As a result, the g-MoS2-BC composites showed faster adsorption rate and greater adsorption capacity for CIP than the original biochar. The coated g-MoS2 nanosheets contributed more to CIP adsorption on the g-MoS2-BC composites due to their greater CIP adsorption capacity than the original biochar. Moreover, the synergistic effect was observed for CIP adsorption on g-MoS2-BC700, and suppression effect on g-MoS2-BC300. In addition, the adsorption of CIP onto g-MoS2-BC composites also exhibited strong dependence on the solution pH, since it can affect both the adsorbent surface charge and the speciation of contaminants. It was reasonably suggested that the mechanisms of CIP adsorption on g-MoS2-BC composites involved pore-filling effects, π-π EDA interaction, electrostatic interaction, and ion exchange interaction. These results are useful for the modification of biochar in exploiting the novel amendment for contaminated soils.

关键词: Adsorption     Ciprofloxacin     g-MoS2 nanosheets     Biochar     Soil remediation    

标题 作者 时间 类型 操作

Preparation and lithium storage performances of g-C

Zhengxu BIAN, Zehua TANG, Jinfeng XIE, Junhao ZHANG, Xingmei GUO, Yuanjun LIU, Aihua YUAN, Feng ZHANG, Qinghong KONG

期刊论文

Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic activity

期刊论文

g-CN-coated MnO hollow nanorod cathode for stable aqueous Zn-ion batteries

期刊论文

结构功能一体化的高性能陶瓷材料的研究与开发

江东亮

期刊论文

Performance of iron-air battery with iron nanoparticle-encapsulated CN composite electrode

期刊论文

GO-modified flexible polymer nanocomposites fabricated via 3D stereolithography

Chi Him Alpha Tsang, Adilet Zhakeyev, Dennis Y.C. Leung, Jin Xuan

期刊论文

Recent advances in special morphologic photocatalysts for NO removal

期刊论文

Pd/Fe3O4 supported on bio-waste derived cellulosic-carbon as a nanocatalyst for CC coupling and electrocatalytic

期刊论文

Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

Huan Liu, Zhen Ma

期刊论文

Novel mutation c.1210-3C>G in with a poly-T tract of 5T affects mRNA splicing in a Chinese patient

期刊论文

NiCo2O4@quinone-rich NC core–shell nanowires as composite electrode for electric double layer capacitor

期刊论文

Effect of noble metal nanoparticle size on CN bond cleavage performance in hydrodenitrogenation: a study

期刊论文

过硫酸盐诱导的缺陷氮化碳中三配位氮(N3C)空位增强光催化产过氧化氢

缪蔚, 王奕杰, 刘莹, 秦贺贺, 褚成成, 毛舜

期刊论文

一种用于用户端设备且工作在2G/3G/4G/IMT/5G频段的小型化超宽带交叉振子天线

郭景丽1,崔伦1,刘英1,孙保华1,李肖锋2

期刊论文

Adsorption characteristics of ciprofloxacin onto g-MoS2 coated biochar nanocomposites

Zhenyu Yang, Rong Xing, Wenjun Zhou, Lizhong Zhu

期刊论文