MATERIALS RESEARCH BULLETIN
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2018
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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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ACS Applied Materials & Interfaces
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2018
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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
LANGMUIR
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2019
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IF 3.683
Lunqiang Jin,Xiang Zhang,Weifeng Zhao,Shengqiu Chen,Zhenqiang Shi,Jingxia Wang,Yi Xie,Feng Liang,Changsheng Zhao
Applications of effective and steady metal catalysts for the hydrogen evolution reaction (HER) via electrolysis of water have a huge potential to relax energy crisis and reduce carbon dioxide emission. Herein, we design a simple, facile, and general approach for the synthesis of a series of transition-metal phosphide nanoparticles embedded in N-doped carbon (NC) nanomaterials using metal salts, abundantly available hexamethylene diamine tetra(methyl phosphonic acid), and urea as precursors. The resultant transition-metal phosphide nanoparticles can serve as high-efficiency and steady HER catalysts. Particularly, when the current density is 10 mA cm–2, the overpotentials of the obtained RhP2@NC are 30, 85, and 70 mV in acid (0.5 M H2SO4), neutral (1 M PBS), and alkaline (1 M KOH) solutions, respectively. Besides, the RhP2@NC exhibits good stability after 10 h in aforementioned solutions. More importantly, it is suited to fabricate other transition-metal phosphide nanoparticles/NC heterostructures by this synthetic strategy. The obtained CoP@NC, FeP@NC, Ni2P@NC, and Cu3P@NC also show relatively high efficiency for HER. Hence, the versatile synthesis strategy opens a new route for the research and fabrication of transition-metal phosphide-based catalysts for HER.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Xiaoyan Liu,Guojun Lan,Yash Boyjoo,Lihua Qian,Sai Gu,Cameron Alexander Hurd Price,Liang Wang,Ying Li,Jian Liu
Ru/carbon catalyst has been considered as a very active catalyst in aqueous-phase hydrogenation of bio-resourced carbonyl compounds. High dispersion of Ru NPs on a carbon support could enhance catalytic performance. In this work, well dispersed Ru nanoparticles on the surface of carbon spheres have been developed by the introduction of nitrogen-doping. Compared with carbon spheres without N-doping, the incorporation of the N-dopant with in the carbon matrix effectively improved the dispersion of Ru nanoparticles, which was confirmed by X-ray photoelectron spectroscopy (XPS) and CO chemisorption characterizations, finding that the presence of quaternary N was responsible for the high dispersion of Ru nanoparticles. Through adjusting the carbonization temperature from 400 to 850 °C, we have shown that the absolute content of quaternary N can be modulated from 3.2 to 22.4 mg g −1 . As a result, the dispersion of Ru nanoparticles was improved from 29.8% to 70.9%. The Ru/N-CS-850 catalyst revealed excellent catalytic performance (9858 h −1 turnover frequency) for the hydrogenation of levulinic acid to γ-valerolactone, also demonstrated very high catalytic activity for other hydrogenation reactions.
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APPLIED SURFACE SCIENCE
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2019
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IF 5.155
Jinhe Shu,Qijian Niu,Nannan Wang,Jun Nie,Guiping Ma
Exploring biomass-derived non-precious metal carbon-based electrocatalysts have attracted intensive interest in the field of energy conversion due to their low-cost, ecofriendly and sustainable. Herein, we report a novel strategy for preparation of Co/N doped hierarchical porous carbon microspheres (Co/NHPCMS), via pyrolysis ZIF-67@SA/NaHCO 3 microspheres prepared by in-situ growth of ZIF-67 on electrospray Co-SA/NaHCO 3 microspheres. ZIF-67 nanocrystals were well distributed on the ions cross-linked alginate/NaHCO 3 microspheres. The pyrolysis of ZIF-67@SA/NaHCO 3 microspheres could provide abundant active sites and rich porous structure. More importantly, NaHCO 3 plays an essential role in obtaining large mesopores and high pore volume , which is benefit to facilitate the diffusion of reactants. With these merits, Co/NHPCMS-600 exhibits an outstanding ORR electrocatalytic performance with a half-wave potential of 0.827 V. Besides, Co/NHPCMS-600 catalyst exhibits superior catalytic stability and tolerance to methanol in the ORR. This work provides a promising route based on sustainable biomass toward high performance electrocatalyst in the field of energy conversion.
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CHEMICAL PHYSICS
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2018
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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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JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
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2018
·Vol. 33
·期 3
·744-748
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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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International Journal of Greenhouse Gas Control
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2017
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IF 3.741
Yan Zhou,Yiheng Rao,Tielin Wang,Klaus-J. Jens
Piperazine (PZ) based amine blends are promising solvents for post-combustion CO 2 capture, but PZ can form potential carcinogenic nitrosamines from nitrite. In this work, the kinetics of the reaction between nitrite and PZ to form N-nitrosopiperazine (MNPZ) was determined in 0.1–0.5 mol L −1 PZ in the presence of 17–170 mmol L −1 formaldehyde at 60–135 °C. The nitrosation of PZ can be catalyzed by formaldehyde, a primary degradation product of PZ. And the reaction involving nitrite and PZ is first order in nitrite, formaldehyde, and hydronium ion. A kinetic model was established, and the activation energy is 33.6 ± 1.8 kJ mol −1 with a rate constant of 2.3 × 10 3 ± 0.4 × 10 3 L 2 mol −2 s −1 at 100 °C. The kinetics will be helpful to develop strategies to reduce nitrosamine formation and accumulation in PZ based CO 2 capture systems.
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ELECTROCHIMICA ACTA
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2017
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IF 4.798
Rui Jiang,Jinhang Fan,Liangyou Hu,Yanpeng Dou,Xuhui Mao,Dihua Wang
An efficient catalyst for hydrogen evolution reaction (HER), nanostructured nitrogen-doped molybdenum carbide (β-Mo 2 C), is reported in this work. The catalyst is prepared via a novel one-step solid-state electrolytic reduction of a mixture of MoS 2 and polypyrrole nanofiber in molten CaCl 2 at 850 °C. As comparison, a series of Mo 2 C materials are prepared by the method using different carbon precursors. TEM tests show that the as-prepared N-doped Mo 2 C is composed of near-spherical nanoparticles with the particle sizes of about 40–60 nm. Nitrogen-doping of Mo 2 C is shown to facilitate the exposure of active centers on the surface of the sample, concurrently modify the electronic property of Mo 2 C to promote electron transfer for HER. As a result, the optimized N-doped Mo 2 C (Mo 2 C- PPyF -1/1) displays a low onset potential of 78.1 mV for HER and a Tafel slope of 59.6 mV dec −1 in 0.5 M H 2 SO 4 , meanwhile exhibits high activity and stability in a broad pH range (0–14). Furthermore, the synthesis method is extended to fabricate other N-doped transition metal carbides (NbC, TaC and TiC). All of the N-doped materials exhibit significantly enhanced activity compared to the undoped ones.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2017
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IF 2.323
Ying Zhang,Yutian Chen,Yu Zheng,Xinxin He,Maogang He
The speed of sound in n-octane and isooctane (2,2,4-trimethylpentane) was measured by the Brillouin light scattering (BLS) method. The examined regions for n-octane are T = (297–580) K along five isobaric lines at p = 0.1, 4.0, 7.0, 10.0, and 12.0 MPa for liquid and T = (573–673) K along ten isobaric lines with p = (3.0–10.0) MPa for supercritical fluid. The examined regions for isooctane are T = (294–525) K along five isobaric lines at p = 0.1, 3.0, 6.0, 10.0, and 12.0 MPa for liquid and T = (543–630) K along six isobaric lines with p = (3.0–10.0) MPa for supercritical fluid. The relative expanded uncertainty of the speed of sound is estimated less than 1.3%. Polynomial representations for the speed of sound in liquid n-octane and isooctane were fitted to the experimental results, respectively. The AADs are 0.27% for n-octane and 0.19% for isooctane. The influence of temperature and pressure on the speed of sound was also analyzed. Moreover, the data were also used to assess the predicted ability of three equations of state for n-octane.
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CERAMICS INTERNATIONAL
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2017
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IF 2.986
Hanqin Liang,Kaihui Zuo,Yongfeng Xia,Dongxu Yao,Jinwei Yin,Yuping Zeng
Lu-Al-Si-O-N tapes with different thickness were used to join gas pressure sintered Si 3 N 4 ceramics. The microstructure of the joints and the influences of the joint thickness and joining temperature on the bonding strength of the as-joined Si 3 N 4 ceramics have been investigated. The highest bonding strength about ~ 300 MPa of the joined specimens was achieved by using 450 µm interlayer at 1450 °C. The existence of Si 3 N 4 nanowires was beneficial for the improvement of the bonding strength by interweaving the oxynitride glass matrix in the joint region.
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Nanomaterials
·
2017
·Vol. 7
·期 10
·338
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IF 3.553
Xiaobo Pan,Xinyue Liang,Longfang Yao,Xinyi Wang,Yueyue Jing,Jiong Ma,Yiyan Fei,Li Chen,Lan Mi
TiO2nanoparticles modified with phthalocyanines (Pc) have been proven to be a potential photosensitizer in the application of photodynamic therapy (PDT). However, the generation of reactive oxygen species (ROS) by TiO2nanoparticles modified with Pc has not been demonstrated clearly. In this study, nitrogen-doped TiO2conjugated with Pc (N-TiO2-Pc) were studied by means of monitoring the generation of ROS. The absorbance and photokilling effect on HeLa cells upon visible light of different regions were also studied and compared with non-doped TiO2-Pc and Pc. Both N-TiO2-Pc and TiO2-Pc can be activated by visible light and exhibited much higher photokilling effect on HeLa cells than Pc. In addition, nitrogen-doping can greatly enhance the formation of1O2and •O2−, while it suppresses the generation of OH•. This resulted in significant photodynamic activity. Therefore, N-TiO2-Pc can be an excellent candidate for a photosensitizer in PDT with wide-spectrum visible irradiation.Keywords:titanium dioxide;phthalocyanine;reactive oxygen species;photodynamic therapy
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