NANOTECHNOLOGY
·
2019
·Vol. 31
·期 6
·065603
·
IF 3.399
Chun Sun,Le Wang,Sijing Su,Zhiyuan Gao,Hua Wu,Zi-hui Zhang,Wengang Bi
White light-emitting diodes (WLEDs) based on all-inorganic perovskite CsPbX3 (X = Cl, Br, I) quantum dots (QDs) have attracted much attention and rely on mixing several colors of perovskites. However, this inevitably leads to a non-uniform light distribution and serious light loss. Here, a novel strategy was demonstrated to obtain white emission by combining the orange and blue emission from CsPb/Mn(Cl/Br)3 QDs. Notably, highly efficient white emission with a photoluminescence quantum yield of 94% was achieved by an anion exchange surface engineering (AESE) strategy. After AESE treatment the surface traps can be eliminated, resulting in improved exciton and Mn2+ emission. A prototype WLED device was fabricated and exhibited excellent optical stability, demonstrating great potential for perovskite QDs in the field of optoelectronics.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 3
·1270-1277
·
IF 3.049
Yufeng Zhang,Jie Xiong,Dingyi Shen,Wenpeng Xia,Jie Yu,Yanfei Zhang,Jun Yang,Shanshan Hu,Yuxin Wan,Haili Wen,Hang Ye,Yucan Liu
A series of color-tunable emitting Na3Sc2(PO4)3:Ce3+/Tb3+/Eu3+ (NSPO) phosphors were prepared by a combination of hydrothermal synthesis and low temperature calcination. The phase structure, photoluminescence and energy transfer properties of the samples were studied in detail. The tunable colors were obtained by co-doping the Tb3+ ions into the NSPO:Ce3+ or NSPO:Eu3+ phosphors with varying concentrations. Under UV excitation, the energy transfers from Tb3+ to Eu3+ in the NSPO host occurred mainly via a dipole–dipole mechanism, and the critical distances of the ion pairs (Rc) was calculated to be 17.94 Å by the quenching concentration method. And that, the emission colors of the NSPO:Tb3+,Eu3+ phosphors could be adjusted from green through yellow to red because of the energy transfer from Tb3+ to Eu3+. Based on its good photoluminescence properties and abundant emission colors, the NSPO:Ce3+/Tb3+/Eu3+ phosphors might be promising as potential candidates for solid-state lighting and display fields.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Yang Zhang,Zhenqian Zhang,Jingyu Li,Guoxin Sui
The uniform dispersion of Fe 3 O 4 nanoparticles and strong interfacial bonding with epoxy matrix are crucial for Fe 3 O 4 /epoxy composite with enhanced mechanical and thermal properties. Cube pure Fe 3 O 4 nanoparticles (PF NPs) by poly (dopamine) (PDA) coated and (3-aminopropyl) triethoxysilane (APTES) grafted (PAF NPs) are successfully prepared via co-precipitation and seed polymerization method with an aim to enhance the dispersion and interfacial bonding with the epoxy matrix. The tensile strength of PAF/epoxy (1 wt%) increases from 57.8 MPa to 65.5 MPa (a rise scope of almost 13.3%) compared to pure epoxy. The thermal stabilities of PAF/epoxy composites with various PAF contents (1 wt%, 2 wt%, 3 wt%) are higher than that of pure epoxy. The saturation magnetization (Ms) of PAF/epoxy increases from 0.125 to 0.7 emu/g with PAF loading contents increasing from 0.5 to 3 wt%. The results suggest that dispersion and interfacial bonding of nanoparticles make a pivotal contribution to the enhanced performances of composites.
✓ 已验证
产品关联
DOI
高影响因子
CURRENT MICROBIOLOGY
·
2019
·Vol. 76
·期 6
·706-712
·
IF 1.595
Li Minghua,Meng Xiumei,Sun Zhiyang,Zhu Chunjie,Ji Huiying
It is well known that cofactors play a key role in the production of different compounds in bioconversion processes, while the high cost of cofactors limits their usage in industrial applications. In the present study, a NADH regeneration system was successfully developed in Lactobacillus plantarum by expressing the fdh gene coding for formate dehydrogenase (FDH) from Candida boidinii. Results indicated that the FDH was expressed with the highest activity of 0.82 U/mg of protein when cells entered early stationary phase. In addition, the expression of FDH increased the intracellular level of NADH and NADH/NAD + ratio in L. plantarum , and therefore, enhanced the NADH-dependent production of 3-phenyllactic acid (PLA) in repeated and fed-batch bioconversions. In brief, the results demonstrate that the NADH regeneration by expressing FDH is a promising strategy for producing NADH-dependent microbial metabolites in L. plantarum .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Hai-Bin Qiu,Yi Hu,Han-Juan Chong,Li Yuan,Guo-Ping Sheng
Ionic liquids (ILs) have been widely applied in chemical industry due to their unique properties. There is mounting evidence that they are toxic to various living organisms. Thus, it is crucial to develop methods to efficiently degrade and mineralize ILs to reduce their potential risks to the environment. In this work, the degradation of 1-butyl-3-methylimidazolium bromide ([C 4 MIM]Br), an imidazolium-based IL, was investigated in aqueous solution via 60 Co γ-ray irradiation. Results show that [C 4 MIM]Br could be effectively degraded by γ-ray irradiation. The irradiation-induced degradation of [C 4 MIM]Br fitted well to the pseudo-first-order kinetics model. The kinetic constant ( k ) increased linearly with the increase of irradiation dose rate (R 2 = 0.942) and solution pH value (R 2 = 0.974), and decreased with the increase of [C 4 MIM]Br concentration. Fourteen intermediates were detected using a liquid chromatography-mass spectrometry analysis. Based on these intermediate products, the degradation pathways and mechanisms of [C 4 MIM]Br were proposed. The free radicals (e.g., aqueous electron (e aq – ), hydroxyl radical ( OH), and hydrogen atom (H )) generated by γ-ray irradiation showed synergistic effects in the degradation and mineralization of [C 4 MIM]Br. Moreover, the toxicity assessment using C. elegans and Chlorella pyrenoidosa as model organisms demonstrates that sufficient γ-ray irradiation could effectively reduce the potential risks of [C 4 MIM]Br and its intermediates to the environment. These findings of this study may offer an efficient and environmentally friendly approach for effectively removing ILs and other persistent organic pollutants.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Hong-bo Huang,Shao-hua Luo,Cai-ling Liu,Yue Yang,Yu-chun Zhai,Long-jiao Chang,Ming-qi Li
Na super ionic conductor (NASICON)-type Na 3 V 2 (PO 4 ) 3 (NVP) has been considered as a potential positive electrode material for sodium ion batteries (NIBs) owing to its high theoretical specific capacity. Nonetheless, the practical application of NVP is hindered by the intrinsically poor electronic conductivity. Herein, polydopamine-derived nitrogen-doped carbon-covered Na 3 V 2 (PO 4 ) 3 /C composites (NVP/C/NC) have been prepared through a self-polymerization of dopamine on the NVP/C surface and subsequent calcination at high temperature. The as-synthesized NVP/C/NC composite cathode exhibits a high initial reversible capacity (109.2 mAh/g at 0.2C), superior rate performance (87.2 mAh/g at a rate up to 20C), and excellent cycling capability (91.2% of the initial capacity is kept after 500 cycles at 2C) in NIBs. Furthermore, compared with NVP/C electrode, the NVP/C/NC electrode presents low resistance and high sodium ions diffusion coefficient . The good performance can be ascribed to the nitrogen-doped carbon layer in improving the electronic conductivity, shortening diffusion length of Na + ions and electrons, and relieving the volume changes of electrode materials. These preliminary results suggest that the as-obtained NVP/C/NC composite is a novel promising electrode material for low-cost sodium energy storage.
✓ 已验证
产品关联
DOI
高影响因子
NANO LETTERS
·
2019
·
IF 12.279
Xiaolei Yuan,Yong Zhang,Muhan Cao,Tong Zhou,Xiaojing Jiang,Jinxing Chen,Fenglei Lyu,Yong Xu,Jun Luo,Qiao Zhang,Yadong Yin
Developing high-performance electrocatalysts for the ethanol oxidation reaction (EOR) is critical to the commercialization of direct ethanol fuel cells. However, current EOR catalysts suffer from high cost, low activity, and poor durability. Here we report the preparation of PdBi-Bi(OH)3 composite nanochains with outstanding EOR activity and durability. The incorporation of Bi can tune the electronic structure and downshift the d-band center of Pd while the surface decoration of Bi(OH)3 can facilitate the oxidative removal of CO and other carbonaceous intermediates. As a result, the nanochains manifest an exceptional mass activity (5.30 A mgPd–1, 4.6-fold higher than that of commercial Pd/C) and outstanding durability (with a retained current density of ∼1.00 A mgPd–1 after operating for 20 000 s). More importantly, the nanochain catalyst can be reactivated, and negligible activity loss has been observed after operating for 200 000 s with periodic reactivation, making it one of the best EOR catalysts.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 16
·4434-4442
·
IF 9.405
Teng Li,Shengqin Liu,Bing Wang,Jingen Long,Jun Jiang,Ping Jin,Yao Fu,Haizhu Yu,Weiran Yang
Glycerol, generated in abundance as the by-product in the process of biodiesel production and saponification, has seen attempts to convert it into value-added chemicals. However, due to the low selectivity of hydrogenolysis of the secondary hydroxyl group, valuable 1,3-substituted chemicals are difficult to obtain from glycerol by chemocatalysis. In this work, glyceric acid (GA), a renewable biomass from glycerol, was quantitatively converted to 3-iodopropionic acid (3-IPA) at 373 K in 3 h by hydroiodic acid mediated hydrogenation. As the reductant in this process, HI is oxidized to I2 and then regenerated in situ by metal catalysts and H2. The reaction pathway was proposed by intermediate identification and verified by a kinetics study and computational method. The catalytic system was shown to be stable and can be reused several times without loss in activity. As a 1,3-substituted chemical, 3-IPA is not only a potential monomer to form poly-3-hydroxypropionic acid, but also a good platform molecule to produce useful chemicals, e.g. 3-hydroxypropionic acid (3-HPA) and acrylic acid (AA), due to its highly reactive nature.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 43
·24904-24914
·
IF 3.049
Zengfeng Wei,Xin Chen,Jiang Duan,Caihong Mei,Dan Xiao,Aidong Zhang
Urushiol is a resource-limited natural coating material with diverse applications; however, the synthesis of urushiol analogues and the realization of their urushiol-like performance remain challenging. Herein, four urushiol analogues, namely, 3-((4-alkenoylpiperazin-1-yl)methyl)catechols with the precise 3-substitution pattern on a catechol as that found in urushiol were synthesized by employing the Mannich reaction of catechol with formaldehyde and N-Boc-piperazine as the key step in a two-step route. By using optimization, the advantages of convenience in operation, cost-effectiveness, and scalability could be obtained. The electropolymerization of these analogues on copper was found to be practical due to their higher aerobic stability than urushiol, affording robust coatings with desirable hardness, adhesion strength, hydrophobicity, and thermal stability. Furthermore, the coatings exhibited effective corrosion protection on copper with initial anticorrosion efficiency up to 99.9% and comparatively higher efficiency (more than 97%) after 4 weeks of immersion in 3.5 wt% NaCl solution. The evidence from the electrochemical and infrared spectroscopic characterization data revealed that the electropolymerization process mechanically involved the free radical coupling of phenoxyl radicals to themselves and to the CC bonds in the side chain, forming a robust crosslinking coating. This work paves a way for the synthesis of high-performance urushiol analogues with potential applications as metal protection materials.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 19
·48664
·
IF 2.188
Yuyang Gao,Shaoying Liu,Qingyin Wang,Gongying Wang
Aiming at meeting the specific market demands and expanding the downstream application of melamine–formaldehyde (MF) resins, a series of (3-aminopropyl) triethoxysilane (APTES) grafted MF (MF-Si) resins were synthesized via an effective method that minimized the hydrolysis of APTES and overcame the polarity discrepancy of APTES with MF resin matrix. The structure of MF-Si resins was characterized by FTIR spectroscopy, Raman spectroscopy, 1 H nuclear magnetic resonance (NMR), and solid state 13 C NMR. It was found that APTES moieties in MF-Si materials afforded increased hydrophobicity, water resistance, and the thermal stability was not affected. With the increasing amount of APTES, the water contact angle of MF-Si films increased from 70.56 to 105.92°and the surface free energy decreased from 46.8 to 23.5 mN/m. The temperature of maximum weight loss rate ( T dmax ) of MF-Si materials decreased slightly from 371.15 to 353.70 °C and the ultimate residual weight of MF-Si materials increased from 12.51 to 30.04% at 800 °C under N 2 . © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137 , 48664.
✓ 已验证
产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2018
·Vol. 296
·期 8
·1365-1372
·
IF 1.967
Zhang Rongli,Jin Zhenzhen,Zhang Cuige,Yang Renchun,Sun Mingyue,Wong Ching-Ping
A kind of electroactive nanoparticles (NPs) was prepared in solution by self-assembling amphiphilic 3-thiophenecarboxylic acid-modified starch (TPCA-St), which was synthesized through esterification reaction. By casting TPCA-St NPs on the surface of gold electrode and subsequent electropolymerization of the thiophene moieties in NP film, the electroconductive TPCA-St NP-based film was formed. After horseradish peroxidase and Nafion were sequentially cast on the film surface, a biosensor was successfully prepared. The prepared biosensor showed high sensitivity for H 2 O 2 detection. The linear range from 1 × 10 −10 to 1 × 10 −5 mol L −1 with a detection limit of 3 × 10 −11 mol L −1 was obtained for H 2 O 2 sensing. The biosensor also showed good repeatability and stability, and it has been successfully used to sense H 2 O 2 in commercial disinfector with satisfactory results.
✓ 已验证
产品关联
DOI
高影响因子
Canadian Journal of Chemistry
·
2018
·Vol. 96
·期 8
·
IF 1.084
Yongshu Li,Nizhou Xu,Guangyao Mei,Yun Zhao,Yiyong Zhao,Jinghui Lyu,Guofu Zhang,Chengrong Ding
A mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and aldoximes has been developed that utilizes Fe(NO3)3·9H2O as the single catalyst and molecular oxygen as the green oxidant. The environmentally benign protocol provides moderate to excellent yield and broad functional groups tolerance and is a valuable synthetic method for practical applications. According the relevant verification experiment, a plausible mechanism has been proposed.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）