ACS Applied Nano Materials
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2019
·
IF 0
Fu Chen,Hui Luo,Yongzhi Cheng,Jieling Liu,Xian Wang,Rongzhou Gong
Electromagnetic (EM) interference and radiation affecting human health and the operation of precision electronic devices have drawn considerable attention in recent years. Herein, a promising microwave-absorbing material, Ag nanoparticles (AgNPs)-decorated Fe/Fe3O4@N-doped carbon (NC) composite, was designed and fabricated with the Fe2O3@polydopamine@Ag hexagonal plates as the precursor. Crystalline structure, phase conversion, micromorphology, static magnetic properties, and EM characteristics of the samples were studied by various analytical techniques. The EM parameters of the obtained samples could be manipulated by increasing the pyrolysis temperature, exhibiting gradually enhanced dielectric and magnetic loss. Optimizing the coating thickness turns out to be a critical factor for regulating microwave absorption. The product obtained at 600 °C performs a maximum reflection loss (RL) value of −37.5 dB (10.64 GHz, 1.6 mm) and an effective absorption bandwidth (RL < −10 dB) up to 7.36 GHz (10.64–18 GHz) with a thickness of only 1.4 mm. In addition, the possible EM wave absorption mechanisms were further investigated in detail. In sum, it has been confirmed that the as-obtained AgNPs-decorated Fe/Fe3O4@NC composite with ultrabroad absorption bandwidths and strong absorption capacity would be an attractive candidate material for effective EM absorption materials in the future.
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JOURNAL OF NANOPARTICLE RESEARCH
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2020
·Vol. 22
·期 1
·1-12
·
IF 2.132
Hou Junjie,Zhou Xuemei,Yang Zhi,Nie Huagui
Oxygen evolution reaction (OER) catalysts are of central importance for electrocatalytic water oxidation and fuel generation, while it is still an urgent requirement to design and develop efficient OER catalysts with rapid kinetics and low overpotentials. Herein, we report an electrochemical deposition method to fabricate carbon nanotubes/N-doped cuprous sulfide (CNTs/N-Cu 2 S) composites using thiourea and a CuSO 4 solution as the S and Cu sources, respectively. The advantages of this strategy include low cost, simple processing and the absence of templates or surfactants that can otherwise affect the electrochemical properties of the products. The N supplied by the thiourea can be used as a doping agent as a result of the in situ formation of small N-Cu 2 S particles, which can increase larger surface area and create more active sites to enhance OER catalytic activity, compared with that obtained with materials synthesized without adding the thiourea. The synergic interface of CNTs and N-Cu 2 S can improve conductivity and efficient chemical transfer in the composites electrodes by introducing CNTs. Under the optimal experimental conditions, the CNTs/N-Cu 2 S-5cyc composites present an excellent activity with the current density of 10 mA cm −2 at a low OER overpotential of 280 mV, the Tafel slope of 63 mV dec −1 and a strong electrochemical stability in 1.0 M KOH solution.
Graphical abstract
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高影响因子
MICROCHEMICAL JOURNAL
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2019
·
IF 3.206
Xu Chen,Jianliang Bai,Yusha Ma,Guojun Yuan,Jing Mei,Lu Zhang,Lili Ren
Recently, carbon dots (CDs) with long wavelength (i.e., orange and red-light) are gradually critical in the bioimaging and biomedical fields. In this paper, a simple one-pot hydrothermal method for preparing bright orange N-doped carbon dots (N-CDs) from p -phenylenediamine has been developed. The resulting N-CDs with abundant surface functional groups show strong orange fluorescence, certain water solubility property and obvious fluorescence quenching to Fe 3+ ions and pH. What's more, the fluorescence of the N-CDs displays a consequent color variation with the increasing concentration of Fe 3+ and pH. In short, N-CDs can be considered as an efficient and multifunctional fluorescent sensor for monitoring pH and Fe 3+ because of their prominent biocompatibility and low toxicity characteristics.
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JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
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2018
·Vol. 33
·期 3
·744-748
·
IF 0.524
Xu Renxin,Cheng Shixin,Zhou Jing,Shen Jie,Li Zheng,Tan Xing
A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-(4-hydroxyphenyl) terahydrophthalic anhydrideimide (HTAM) was synthesized. The structural characterization of the epoxy-imide resin was conducted by FT-IR spectra. 4,4’-diaminodiphneylmethane (DDM) was used as a curing agent for the epoxy-imide resin. The thermal properties of the cured resin were evaluated with dynamic mechanical analyses (DMA) and thermogravimetric analysis (TGA). The results showed that the cured resin exhibited a high glass transition temperature ( T g ) of 186 °C when the molar amount of HTAM was 0.04 mol in the resin. The yields of the cured resin at 800 °C raised from 16.45% to 19.41%. The flexural properties were also measured, the flexural strength raised from 79.4 to 95.7 MPa, and the flexural modulus exhibited from 2.6 to 3.0 GPa.
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Polymers
·
2018
·Vol. 10
·期 4
·441
·
IF 2.935
Weiqiu Wen,Jianwei Guo,Xi Zhao,Xiong Li,Hongmei Yang,Jem-Kun Chen
Considering the poor compatibility and water-resistance of sulfonate flame retardants for polycarbonate (PC), an efficient S/N-based flame retardant named 1,3,5,7-tetrakis(phenyl-4-sulfonyl-melamine)adamantane (ASN) has been developed. Fire properties studies of PC/ASN blends indicate that the addition of 0.10 wt % ASN imparts a V-0 rating and a limited oxygen index (LOI) value of 30.1% to PC specimens, and ASN can suppress the heat and toxic gas release of PC composites. Additionally, PC/ASN blends are believed to be exceptional materials for outdoor PC applications due to their superior water-resistance properties. Moreover, mechanical properties were further systematically investigated, and the correlative results indicate that the tensile strength and rigidity of specimens are improved with the addition of ASN.Keywords:flame retardant;adamantane;polycarbonate;fire properties;water-resistance
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PubMed
高影响因子
Small
·
2018
·Vol. 14
·期 19
·1800367
·
IF 9.598
Hui Li,Si-Min Xu,Hong Yan,Lan Yang,Sailong Xu
Exploring highly efficient and stable oxygen evolution reaction (OER) electrocatalysts such as transition-metal phosphides (TMPs) is critical to advancing renewable hydrogen fuel. TMP nanostructures typically involving binary or ternary TMPs tuned by cation or anion doping are suggested to be promising low-cost and durable OER catalysts. Herein, the preparation of CoP/CoP 2 composite nanoparticles encapsulated within N,P-doped carbon nanotubes (CoP/CoP 2 @NPCNTs) is demonstrated as a synergistic electrocatalyst for OER via the calcination of a CoAl-layered double hydroxide/melamine mixture and subsequent phosphorization. Facile visualization by scanning electron microscopy in conjunction with electron backscatter diffraction demonstrates the encapsulation of the CoP/CoP 2 nanoparticles within the N,P-codoped CNTs. Electrocatalytic evaluation shows that the composite electrode requires a low overpotential of 300 mV for the OER at 10 mA cm −2 in a 1.0 m KOH solution and, in particular, exhibits an excellent long-term durability of ≈100 h, which is superior to that of the state-of-the-art RuO 2 electrocatalyst. Density functional theory calculations reveal that the synergistic effect of CoP and CoP 2 can enhance the electrocatalytic performance. In addition, molecular dynamics simulations demonstrate that the generated O 2 molecules can readily diffuse out of the CNTs. Both the effects give rise to the observed OER enhancement.
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高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Peihao Li,Wei Wang,Sheng Gong,Fan Lv,Hanxin Huang,Mingchuan Luo,Yong Yang,Chao Yang,Jinhui Zhou,Chang Qian,Bin Wang,Qian Wang,Shaojun Guo
With its inherent zig-zag layered structure and open framework, Na2Ti3O7 (NTO) is a promising anode material for potassium-ion batteries (KIBs). However, its poor electronic conductivity caused by large band gap (∼3.7 eV) usually leads to low-performance KIBs. In this work, we synthesize the fluff-like hydrogenated Na2Ti3O7 (HNTO) nanowires grown on N-doped carbon sponge (CS) as a binder-free and current-collector-free flexible anode for KIBs (denoted as HNTO/CS). High-resolution X-ray photoelectron spectroscopy (XPS) and electron spin-resonance spectroscopy (ESR) confirm the existence of Ti–OHs and O vacancies in HNTO. The first-principles calculation discloses that both Ti–OHs and O vacancies are equivalent to n-type doping because they can shift the Fermi level up to the conduction band, thus leading to a higher electronic conductivity and better performance for KIBs. In addition, the N-doped CS can further reinforce the conductivity and avoid the aggregation of HNTO nanowires during cycling. As a result, the as-made HNTO/CS can deliver a capacity of 107.8 mAh g–1 at 100 mA g–1 after 20 cycles, and keep the capacity of 90.9% and 82.5% after 200 and 1555 cycles, respectively, much better than the samples without hydrogenation treatment or N-doped CS and reported KTixOy-based materials. Our work highlights the importance of hydrogenation treatment and N-doped CS in enhancing the electrochemical property for KIBs.
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高影响因子
MATERIALS RESEARCH BULLETIN
·
2018
·
IF 2.873
Xing Liu,Yunhong Jiang,Kefeng Li,Fu Xu,Ping Zhang,Yanhuai Ding
Electrochemically active SnO 2 materials are prospective alternatives for graphite toward better flexible LIBs. However, significant volume changes and structural pulverization restrict the cycling stability and high capacity of SnO 2 . Here, we report a binder and conductive additive free core-shell N-doped carbon @SnO 2 hybrid paper by a subtle coaxial-electrospinning method. Core-shell N-doped C@SnO 2 fibers not only offer rapid ionic transport and sufficient buffer space for the volume expansion during the Li insertion and extraction reactions, but also enable high flexibility against both compression and bending deformation. As an anode for LIBs, the hybrid materials delivered a large initial capacity of 1799 mAhg −1 with capacity retention of 729 mAhg −1 after 100 cycles at a current rate of 390.5 mAg −1 . More importantly, flexible N-doped C@SnO 2 fabrics exhibit excellent electrochemical performance even after a rough treatment, suggesting a facile strategy for the fabrication of electrochemically stable electrodes for flexible LIBs.
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高影响因子
CHEMICAL PHYSICS
·
2018
·
IF 1.707
Hang Zhang,Yan Zhang,Junwei Yin,Zhenzi Li,Qi Zhu,Zipeng Xing
In-situ N-doped mesoporous black TiO 2 photocatalyst is fabricated by a facile sol-gel method combined with an in-situ solid-state chemical reduction technique, using urea as nitrogen resource. The N-doped mesoporous black TiO 2 possesses high surface area of 96 m 2 g −1 , large pore size of 5.4 nm and narrow band gap of 2.05 eV. Meanwhile, the optical absorption extends to visible light region because of Ti 3+ and N co-doping. The N-doped mesoporous black TiO 2 exhibits higher photocatalytic activity than that of others under visible light irradiation for photocatalytic degradation of methyl orange (MO) and rhodamine B (RhB), which is up to 93.27% and 93.64%, respectively. The enhancement is ascribed to the synergistic effect of the N and Ti 3+ co-doping extending the visible light absorption, the separation efficiency of photogenerated charge carriers, and the mesoporous structure with large surface area offering more surface active sites, which is beneficial for improving the photocatalytic activity.
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ACS Applied Nano Materials
·
2018
·
IF 0
Shengshuai Gao,Qingda An,Zuoyi Xiao,Shangru Zhai,Dongjiang Yang
Microwave absorption materials with great reflection loss and wide absorption band that can provide electromagnetic waves (EMWs) absorption with minimal thickness are highly desirable, particularly when they could be controllably fabricated through a facile process. Herein, N-doped three-dimensional (3D) carbonaceous composites with highly dispersed nickel nanoparticles (N-SA/Ni-X, X = 3%, 6%, 9%) were successfully prepared by a facile one-step encapsulation process and carbonization. The performance of the absorber has a significant enhancement due to the introduction of nitrogen elements into a carbon network for controlling the dispersion and size distribution of Ni nanoparticles. When a 6% Ni2+ mass percentage was used, the maximum reflection loss (RL) could reach −42.2 dB at 9.8 GHz. Moreover, the effective absorption (below −10 dB) bandwidth can be increased by 2.3 GHz, from 8.5 to 10.8 GHz, with the absorber thickness of only 2 mm, and it can be tuned from 2.8 to 14.4 GHz by adjusting the thickness from 1.5 to 5 mm. The excellent electromagnetic-wave-absorbing performance could be assigned to the combinatorial advantages of the lightweight conductive porous network with favorable dielectric loss and magnetic loss features induced by highly dispersed Ni nanoparticles. These newly fabricated N-SA/Ni-X composites could be regarded as promising candidates for lightweight and high-performance microwave absorption materials.
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ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Wei Ma,Lin Li,Xinghuan Lin,Yingfeng Wang,Xuehong Ren,Tung-Shi Huang
Cutaneous hemorrhage often occurs in daily life which may cause infection and even amputation. This research aims to develop a novel chitosan dressing impregnated with ZnO/N-halamine hybrid nanoparticles for quick antibacterial performance, outstanding hemostatic potential, high porosity, and favorable swelling property through combining sonication and lyophilization processing. After 30 days of storage, about 90% bacterial cell viability loss could be observed toward both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli O157:H7 within 30 min of contact by colony counting method. The hybrids assembled much more platelet and red blood cell as compared with pure chitosan control. Moreover, the lower blooding clotting index value gave evidence that these composites could control hemorrhaging and reduce the probability of wound infection. No potential skin irritation and toxicity were detected using in vitro cytocompatibility and a skin stimulation test. Therefore, this work demonstrated a facile and cost-effective approach for the preparation of N-halamine-based hybrid sponges which show promising application for wound dressings.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Yuwei Shen,Dingchang Shi,Liangbin Liu,Fan Liao,Wenxiang Zhu,Mingwang Shao
The electrocatalytic activity is closely associated with the electronic structure of catalysts. Electron-deficient palladium (Pd) has been proved to show better oxygen reduction reaction performance than the electrophilic one due to the downshift of the d-band center. In this work, Pd nanoparticles are uniformly dispersed in F, N-doping graphene with the assistant of silicon nanowires and hydrofluoric acid (Pd/F, N-doping G). A strong interaction between the metal and doped-graphene leads to the electron-deficiency of the modified Pd, which is beneficial for obtaining proper adsorption energy of oxygen species. The as-prepared Pd/F, N-doping G-3 catalyst shows a four-electron oxygen reduction pathway with large half-wave potential of 0.87 V and high onset potential of 0.99 V in 0.1 M KOH. In addition, the Pd/F, N-doping G-3 based zinc-air battery exhibits an open potential of 1.40 V and a high power density of 229 mW·cm–2.
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高影响因子
危险品化学品经营许可证（带存储）