Journal of Materials Research and Technology-JMR&T
·
2020
·
IF 5.289
Zepeng Lv,Yijie Wu,Jie Dang,Dong Liu,Liwen Hu,Kaiping Du,Haibo Sun
The effect of yttrium on the reaction of tungsten oxide with CO was studied for the preparing various morphologies and size of tungsten carbide. The reaction rate, phase composition, particles size and morphology, surface area of samples were studied by TG (thermogravimetry), XRD (X-ray diffraction), SEM (scanning electron microscopy) and BET (Brunauer–Emmett–Teller), respectively. It was found that the reaction route was following WO 3 → W 18 O 49 → WO 2 → WC at lower temperature, while at higher temperature, an intermediate phase W was formed and then carbonized to WC. During the reaction of pure WO 3 or mixtures (1 wt.% Y(NO 3 ) 3 + WO 3 ) with CO at lower temperature, the final products almost maintained the large irregular block shape. With the increase of temperature, the large WC particles were degraded and the obtained sub-particles became much more dispersed. After the addition of yttrium nitrate, the rod-like sub-particles were transformed into more stable polyhedral-shaped sub-particles with a smaller size. Furthermore, the mechanism of effect of yttrium on prepared tungsten carbides were analyzed in detail.
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 31
·5057-5066
·
IF 5.342
Jianrui Zhang,Xiaocui Han,Cheng Yue,Di Liu,Ziyu Lin,Yirong Sun,Liyuan Chen,Jinhui Pang,Zhenhua Jiang
A new diamine monomer with a dioxinyl bipyrimidine group was synthesized. Polyimide containing a bipyrimidine group was successfully homopolymerized by chemical imidization. Analyses to determine the structure and properties of these polymers were conducted using 1H NMR and FTIR spectroscopy and gel permeation chromatography (GPC). For the first time, cobalt acetate was incorporated into the synthesized polyimide to fabricate cobalt-complexed polyimide thin film composite membranes (TFCMs) by spin coating. To fully understand the behavior of cobalt complexed TFCMs, these membranes were synthesized and then characterized by FTIR spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC) to survey the effects of cobalt acetate on polyimide. The morphologies of TFCMs were determined using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Phase separations and defects were absent in all cobalt-complexed TFCMs; the average thickness of the films ranged from 550 to 600 nm. This strongly suggested that cobalt acetate has good compatibility with bipyrimidine polyimide. The gas separation performance for TFCMs was also determined with the following results: the CO2 permeance of DMD-PI-3.0 (mixing 3.0 wt% cobalt acetate) TFCMs was 69.9 GPU at 35 °C and 1.5 bar while the selectivity of CO2/CH4 was 44.79 for DMD-PI-15 TFCMs. In short, this work reports a promising method to utilize the separation characteristics of polyimide TFCMs by incorporating cobalt ions.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Yafei Guo,Guodong Wang,Xi Yao,Bingqian Liu
Several NiO–CuO–CeO 2 catalysts were prepared via different methods and characterized by different techniques. Structure-activity relationships of the catalysts were demonstrated, and the effect of preparation methods on CO oxidation behaviors was illustrated. Catalytic results evidenced that the NiCuCe-CP and NiCuCe-SG catalysts prepared by co-precipitation and sol-gel methods exhibited better CO oxidation activities and kinetic performance, as evidenced by their lower T 50 values (102 °C and 100 °C) and apparent activation energies (48.80 and 59.28 kJ/mol) as well as higher reaction rates (3.84 and 3.45 μmol/g/s). The XRD and HRTEM results suggested that the active species showed uniform dispersion with minimum crystallite size in the desired catalysts. The XRD, XPS , H 2 -TPR and Raman analysis suggested the formation of Ce 1- x Cu x O 2- δ and Ce 1- x Ni x O 2- δ solid solutions, indicating that the co-precipitation and sol-gel methods reinforced the interactions amongst the ternary metal oxides . This would afford the catalysts more oxygen vacancies for boosted CO oxidation activity. The mechanism was then proposed with the dual synergetic effects in solid solutions for facilitated oxygen mobility and the amorphous active metal oxides for promoted CO chemisorption . The desired NiCuCe-CP and NiCuCe-SG catalysts show potential application for CO abatement in closed-loop air revitalization.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2020
·
IF 4.389
Mengyao Liu,Manfei Fu,Xiaoye Yang,Guoyong Jia,Xiaoqun Shi,Jianbo Ji,Xianghong Liu,Guangxi Zhai
Multidrug resistance (MDR) in tumor has long been considered a major factor in the failure of tumor chemotherapy. P-glycoprotein (P-gp)-mediated drug efflux plays a significant role in the MDR of tumor. Herein, paclitaxel (PTX) and P-gp inhibitor quercetin (QC) co-loaded and chondroitin sulfate (ChS)-coated mesoporous silica nanoparticles (MSNs) ( [email protected] ) were developed to reverse MDR in breast cancer and improve chemotherapy efficacy. The dual drug-loaded nanoparticles (NPs) showed a nanoscale size of ∼ 227.2 nm and redox-responsive drug release property. In vitro cell experiments showed that NPs exhibited CD44 receptor-mediated active targeting in MCF-7/ADR cells. The dual drug-loaded NPs had lower IC 50 value, higher apoptosis rate, obvious G2M phase arrest as well as stronger microtubule destruction in MCF-7/ADR cells compared to PTX-loaded NPs, suggesting that QC addition, significantly, improved the sensitivity of MCF-7/ADR cells to PTX. Further study found that QC-loaded NPs down-regulated the expression of P-gp. Notably, the dual drug-loaded NPs exhibited tumor-targeting ability, prolonged tumor retention time and effective anti-tumor effect without obvious toxicity to normal tissues in vivo . Taken together, our research provides a viable approach to overcome MDR in breast cancer.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 27
·14863-14869
·
IF 6.895
Shuli Yin,You Xu,Songliang Liu,Hongjie Yu,Ziqiang Wang,Xiaonian Li,Liang Wang,Hongjing Wang
The development of doped noble metal catalysts with nonmetal elements to improve the catalytic performance toward the oxygen reduction reaction (ORR) is significant for proton exchange membrane fuel cell technology. Here, we report a one-pot for dual-nonmetal-doping strategy for the synthesis of S and P-co-doped mesoporous PtPd nanocages (PtPdSP mNCs) by using pre-synthesized mesoporous PtPd nanocages (PtPd mNCs) as the precursor and triphenylphosphine sulphide as both S and P sources. Benefitting from the combined advantages of metal–nonmetal incorporation, hollow cavity and surface porosity, the resultant quaternary PtPdSP mNCs exhibit outstanding ORR activity and long-term stability. This research work provides a good strategy for the doping of two or more selected nonmetallic elements into metallic nanocrystals with a controllable structure and composition.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Yueying Wang,Xuetao Hu,Wenting Li,Xiaowei Huang,Zhihua Li,Wen Zhang,Xinai Zhang,Xiaobo Zou,Jiyong Shi
A novel fluorescent probe based on the static quenching and the inner filter effect between boron nitrogen co-doped carbon quantum dots (B, N-CDs) and Cr(VI) was developed for the quantitative determination of Cr(VI) in real water samples. B, N-CDs were prepared using the hydrothermal method with ammonium citrate and bis(pinacolato) diboron as raw materials. Compared with undoped CDs, the fluorescence properties of the B, N-CDs were improved. The fluorescence quantum yield of the B, N-CDs was as high as 59.01%. After optimization of the experimental parameters, the B, N-CDs could be used as a fluorescence probe to detect Cr(VI). Strong linear correlation ( R 2 = 0.9986) was established in the Cr(VI) concentration range 0.3–500 μM, and a detection limit of 0.24 μM was achieved. Moreover, the B, N-CDs successfully detected Cr(VI) in real water samples, indicating that they have broad application prospects in the sensitive detection of Cr(VI).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2019
·
IF 10.159
Yawei Sun,Zhao Liu,Fang Chen,Mi Xu,Jinli Zhang,Wei Li
It is a great challenge to regulate the mechanical properties precisely with both softness and toughness so as to match the requirements of various flexible device applications. Inspired by the three-dimensional network of collagen in connective tissues, a novel biopolymer poly(caprolactone-co-urethane) with hierarchical cross-links was synthesized on the basis of polycaprolactone (PCL) and composite chain extenders of tannic acid (TA) and 1,4-butanediol (BDO). The biopolymer P(CL-TAx/BDOy) possesses both physical and chemical cross-links in coordination with phase separation microstructure, sensitive to the molar ratio of TA/BDO. The optimal P(CL-TA1/BDO1) shows connective tissue-like properties, possesses an initial modulus less than 0.5 MPa but high toughness (61.2 MJ m–3), unique adhesive property, and shape memory behavior. A flexible actuator was prepared by P(CL-TA1/BDO1), exhibiting the shape transformation behavior by an electricity stimulation. This work provides a novel facile method to design biopolymers, including tuning the mechanical properties and integrating multifunctions through the hierarchical cross-link strategy.
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Penghui Chen,Qiang Liu,Xiaoying Li,Yagang Feng,Xiaopu Chen,Xin Liu,Lexiang Wu,Jiang Li
Y 0.16 Zr 0.84 O 1.92 nanopowders were co-precipitated from the mixed solution of zirconium oxychloride and yttrium nitrate using ammonia as the precipitant. The influences of terminal pH value on the chemical composition and morphology of the Y 0.16 Zr 0.84 O 1.92 precursors and powders were characterized. The precursors with terminal pH = 8.5–9.25 completely transform to cubic ZrO 2 phase when calcined at 800 °C. The Y 0.16 Zr 0.84 O 1.92 powder with terminal pH = 9.0 shows the best dispersity, which is beneficial to the fabrication of transparent ceramics. Using the synthesized nanopowders as starting materials, Y 0.16 Zr 0.84 O 1.92 ceramics were prepared by pre-sintering at 1350 °C for 2 h in air and HIP post-treatment at 1800 °C for 3 h under 200 MPa Ar without sintering additives. The Y 0.16 Zr 0.84 O 1.92 ceramic sample fabricated from the powder with terminal pH = 9.0 shows the best optical quality, and its in-line transmittance exceeds 56.4% in the region of 400–850 nm, reaching 67.8% at 800 nm.
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2019
·Vol. 13
·期 1
·79-85
·
IF 8.515
Wang Tian-Jiao,Liu Xiaoyang,Li Ying,Li Fumin,Deng Ziwei,Chen Yu
Electrochemical water splitting (EWS) is a highly clean and efficient method for high-purity hydrogen production. Unfortunately, EWS suffers from the sluggish and complex oxygen evolution reaction (OER) kinetics at anode. At present, the efficient, stable, and low-cost non-precious metal based OER electrocatalyst is still a great and long-term challenge for the future industrial application of EWS technology. Herein, we develop a simple and fast approach for gram-scale synthesis of flower-like cobalt-based layered double hydroxides nanosheet aggregates by ultrasonic synthesis, which show outstanding electrocatalytic performance for the oxygen evolution reaction in alkaline media, such as preeminent stability, small overpotential of 300 mV at 10 mA·cm −2 and small Tafel slope of 110 mV·dec −1 .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2019
·Vol. 323
·期 2
·993-1002
·
IF 1.186
Ma Zhili,Wang Yanfei,Luo Yige,Xie Xiaoqing,Xiong Zeng
Highly crosslinked organic–inorganic hybrid polymer poly(cyclotriphosphazene-co-melamine) microspheres (PZM) were synthesized by a simple method. The microspheres was characterized by FTIR, SEM and EDX. It was applied to eliminate thorium(IV) from aqueous solution under various conditions, i.e., pH, initial concentration, dosage and contact time. The experimental data were well-imitated via the pseudo-second-order kinetic model and its adsorption processes comply with the Langmuir isotherm model. Adsorption thermodynamic studies demonstrated that the adsorption process, in essence, was spontaneous and endothermic. Furthermore, the maximum experimental adsorption capacity was 98.6 mg g −1 for initial thorium(IV) concentration 50 mg L −1 . When pH = 0.0, the thorium(IV) removal efficiency reached at 76.9%, which indicates that the adsorbent can also was used in a peracid environment. Adsorption behavior of thorium(IV) onto the microspheres were weakly affected via temperature, implying that adsorption would be done at room temperature.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Jianian Chen,Mingyu Chu,Fenglei Lyu,Jin Gong,Linzhong Wu,Lijia Liu,Yong Xu,Qiao Zhang
Two-dimensional (2D) metal carbides, carbonitrides, and nitrides (MXenes) have recently emerged as promising candidates in catalysis due to their unique properties. In this work, we composited Ti3C2 with Co-embedded N-doped carbon nanotubes (CNTs) via the pyrolysis of zeolitic imidazolate frameworks (ZIF-67) for propyne selective hydrogenation. Detailed characterizations show that strong synergistic effects are observed between the Ti3C2 and Co-embedded N-doped CNTs in the composite catalysts. This work provides an efficient strategy to achieve N-doping on Co nanoparticles, which play a vital role in the propyne selective hydrogenation. The optimized catalyst gives a high propyne conversion (∼99%) and high propene selectivity (∼96%) on propyne selective hydrogenation at 150 °C, which surpasses the reported non-noble metal catalysts in literature works. This work may not only open an avenue for obtaining active and selective catalysts for propyne selective hydrogenation but also promote research on the role of MXenes in catalysis.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 58
·33997-34003
·
IF 3.049
Xiao Zhou,Haoran Yu,Yang Liu,Yong Kong,Yongxin Tao,Yong Qin
Co, Al and N tri-doped graphene (CANG) was successfully fabricated via annealing N-doped graphene with Co and Al precursors. The material was characterized by scaning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, physical adsorption, and X-ray photoelectron spectroscopy (XPS). It was found that the as-prepared CANG features a robust three-dimensional hierarchically porous structure. The contents of Co and Al can achieve the maximum value of 2.18 at% and 0.51 at% at the annealing temperature of 950 °C. Upon using the electrocatalyst for the hydrogen evolution reaction (HER), the CANG exhibited remarkable electrocatalytic performance in both acidic (η10 = 105 mV) and alkaline media (η10 = 270 mV), and outperforms Co,N-codoped graphene and Al,N-codoped graphene, respectively. In combination with the density functional theory (DFT) calculations, it was revealed that the introduction of the Al heteroatom can decrease the absolute value of hydrogen adsorption free energy (ΔG(H*)) of Co–N–C catalysts, thus greatly enhancing the HER activity. This discovery will provide new guidance to the design of advanced and inexpensive carbon materials for fuel cell, water-splitting and other electrochemical devices.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）