Journal of Cleaner Production
·
2022
·
IF 11.072
Shunan Yin,Jinxian Zhao,Shiping Wu,Xuhui Wang,Yanhong Quan,Jun Ren
Electrochemical reduction of CO 2 to valuable chemicals using electricity from renewable sources is a promising approach to realize the carbon cycle. Here, a novel bimetallic nitrogen-doped carbon catalyst (M-N-C, where M denotes the metal) CoCu–N–C electrocatalyst has been synthesized by pyrolyzing a copper-doped cobalt(II) acetate–phenanthroline complex formed from the metal acetates and 1,10-phenanthroline dissolved in ethanol. The optimal CoCu–N–C catalyst with molar ratio of Cu/(Co + Cu) = 0.15 displayed superior performance, enabling a faradaic efficiency of CO production of 76.5% at an overpotential of 0.57 V as well as an increased CO current density of 8.48 mA cm −2 at −0.98 V versus reversible hydrogen electrode (far superior than the Co–N–C of 4.20 mA cm −2 and Cu–N–C of 0.07 mA cm −2 ) and a decreased charge-transfer resistance compared with Co–N–C and Cu–N–C catalysts. The addition of Cu, which serves as a structure promoter to improve the dispersion of Co, thereby providing sufficient Co-N x active sites for the electrochemical CO 2 reduction reaction (CRR). Moreover, doping Cu changes the electronic environment around Co slightly and promotes the charge transfer capability so that reduces the energy barrier of potential-limiting energy, thereby improving the CRR performance of catalyst.
研究领域:
材料科学
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电化学
·
可再生能源
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
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IF 3.862
Faliang Luo,Juntao Ren,Chunyu Li,Yanming Hu,Guangyuan Zhou
A styrene derivative, 4-N,N-dimethylaminostyrene (MAS), serving as both catalyst and monomer was exploited in reversible complexation mediated polymerization (RCMP). Radical trap experiment and UV–vis spectroscopy analysis revealed that MAS as a catalyst could abstract iodine from iodine-containing compound to generate propagating radical species. Kinetic studies demonstrated that the polymerization of styrene in the presence of MAS proceeded in a “living”/controlled manner, affording polymers with controlled molecular weights and narrow molecular weight distributions. The livingness of the obtained polymer was confirmed by chain extension. Determined by water contact angle measurement, incorporation of MAS into the polymer led to the enhancement of surface energy. Moreover, using α,ω-bis(2-iodo-2-phenylacetoxy)-end functionalized cis -1,4-polyisoprene as a macroinitiator which was synthesized through cross-metathesis of cis -1,4-polyisoprene with cis -1, 4-bis(2-iodo-2-phenylacetoxy)-2-butene, the polymerization of styrene in the presence of MAS also exhibited typical features of “living”/controlled radical polymerization to yield polystyrene-block-polyisoprene-block-polystyrene.
研究领域:
高分子科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2021
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IF 4.076
Yunping Zhoujin,Xing Yang,Mingtao Zhang,Ju Guo,Sean Parkin,Tonglei Li,Faquan Yu,Sihui Long
A lactam–lactam dimer (LLD) and lactam NH···O═C (amide) catemer (LAC) are two competing motifs in N-phenyl-2-hydroxynicotinanilides (PHNAs). Steric effects play an important role in determining the outcome of this competition, and in general, PHNAs with no or negligible steric hindrance take on a near-planar conformation and form LLDs, rather than the widely observed amide NH···O═C hydrogen-bond chains. Conversely, those with significant steric hindrance are forced to take on a twisted conformation and form a lactam NH···O═C (amide) hydrogen bond. Nevertheless, steric factors are not the only criteria, as an LLD and an LAC have been observed in the two polymorphs (1-I and 1-II) of 2-hydroxy-N-m-tolyl-nicotinamide (namely 2-oxo-1,2-dihydropyridine-3-carboxylic acid m-tolylamide, compound 1), although the molecules in both forms have a nearly identical conformation, in contrast to five other newly synthesized PHNAs (2–6), whose crystal structures are sustained on the LLD. Thus, synthon polymorphism is possible in conformationally planar PHNAs. Theoretical studies were performed to provide an explanation for this observation. The lattice energies of the two forms of 1 showed only an insignificant difference. A Hirshfeld analysis revealed that the loss of stability due to less hydrogen bonding in 1-II is compensated by the participation of π–π stacking. Other than the commonly observed LLD in the crystals, π–π stacking provides a significant stabilization for each crystal, with its particular effects being dependent on the substitution pattern of the compound. A noncovalent interaction (NCI) analysis further provided a visual demonstration of the important intermolecular interactions. Potentially the other planar compounds could behave in a similar manner.
研究领域:
晶体学
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理论化学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2021
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IF 4.354
Haopeng Wu,Chukai Shao,Di Wu,Liang Jiang,Hongquan Yin,Fu-Xue Chen
A highly regioselective protocol for intermolecular thiocyanation-amination of alkynes by N-thiocyano-dibenzenesulfonimide (NTSI) as the SCN and nitrogen sources has been developed. A C–S bond and C–N bond are simultaneously constructed in only one step. The reaction under simple mild conditions features a broad substrate scope, atom economy, high yields (up to 94%), and excellent functional group tolerance.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
PubMed
高影响因子
Nanoscale
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2013
·Vol. 5
·期 20
·9764-9772
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IF 6.233
Dongfang Hou,Xianluo Hu,Pei Hu,Wei Zhang,Mingfei Zhang,Yunhui Huang
A novel p–n junction photocatalyst of Bi4Ti3O12 nanofibers–BiOI nanosheets has been fabricated through a simple and economical technique of electrospinning combined with a successive ionic layer adsorption and reaction (SILAR) process. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectra (DRS), and photoluminescence (PL) spectroscopy. The as-formed Bi4Ti3O12 nanofibers are composed of inter-linked nanoparticles of 50–80 nm in size. The thickness of the as-grown BiOI nanosheets is about 10 nm and the size of the BiOI nanosheets increases with the SILAR cycles. In particular, many {001} facets of BiOI nanosheets are exposed, which is favorable to enhance the visible-light photocatalytic activity. The p–n junction photocatalyst exhibits enhanced visible-light-driven photocatalytic activity for decomposition of rhodamine B (RhB) and phenol. The enhanced photocatalytic activity can be attributed to the extended absorption in the visible light region resulting from the BiOI nanosheets and the effective separation of photogenerated carriers driven by the photo-induced potential difference generated at the Bi4Ti3O12–BiOI p–n junction interface.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Xiaohan Wang,Zhiqing Yu,Jinxiao Sun,Qiang Wei,Haoran Liu,Wenbin Huang,Luyuan Zhao,Meng Si,Yasong Zhou
A series of in situ dodecyl trimethyl ammonium bromide (DTAB)-modified small-crystal Y zeolites have been successfully synthesized by DTAB addition to the seed synthesis procedure, which was used to create the small crystal size Y zeolites. Compared to the Y zeolites prepared without DTAB, the Y zeolites prepared with DTAB have a uniform morphology and mesoporous structure, a larger specific surface area (up to 32.3 m2 g–1 increase), a smaller crystal size (up to 66 nm reduction), and more Brönsted acid sites (up to 55 μmol/g increase). After loading with NiW, the corresponding NiW catalysts were utilized in the hydrocracking of n-hexadecane. It is evident from the catalytic performance that the catalysts containing DTAB-modified small-crystal zeolites have a higher yield and selectivity of primary cracking products compared with the Y zeolites without DTAB modification. Moreover, the conversion of n-hexadecane is also higher due to its low mass-transfer resistance, high dispersion, and sulfation of W species. When the molar ratio of DTAB/Al2O3 is 0.15, the corresponding catalyst has the optimum balance between cracking and hydro–dehydrogenation activity. Therefore, it has the most excellent catalytic performance and a 7.3% increase in C8–C12 yield.
研究领域:
催化材料
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石油化学工程
✓ 已验证
DOI
高影响因子
JACS Au
·
2024
·
IF 8.5
Xixi Liu,Liang Huang,Yurong He,Peng Zhou,Xuedan Song,Zehui Zhang
It remains challenging to construct C═N bonds due to their facile hydrogenation. Herein, a single Co atom catalyst was discovered to be active for the selective construction of C═N bonds toward the synthesis of imines and N-heterocycles via reductive coupling of nitroarenes with various alcohols, including inert aliphatic ones. DFT calculations and experimental data revealed that the transfer hydrogenation proceeded via the intramolecular hydride transfer and the transfer of H from the α-Csp3-H bond to the nitro group was the rate-determining step. The single Co atoms served as a bridge to transfer the electrons from the catalyst to the adsorbed alcohol molecules, resulting in the activation of the α-Csp3-H bond. Unlike metal nanoparticles, the C═N bonds in imine products can be reserved due to the large steric hindrance from substituents on C and N. DFT calculation also confirmed that transfer hydrogenation of the C═N bonds in imines is thermodynamically unfavored with a much higher energy barrier compared with the transfer hydrogenation of the –NO2 group (1.47 vs 1.15 eV).
研究领域:
化学
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催化反应
·
理论计算
✓ 已验证
DOI
PubMed
高影响因子
POLYMER SCIENCE SERIES B
·
2022
·Vol. 64
·期 5
·644-650
·
IF 1.023
Zheng X. C.,Wu C. L.,Xiong J.,Lei H.
Abstract Poly( N -isopropylacrylamide) was grafted onto the surface of polypropylene by a two-step surface photo-grafting method using benzophenone as a photosensitizer to impart surface temperature sensitivity to polypropylene. The structure of graft-copolymer was characterized by infrared spectroscopy and scanning electron microscopy. Its temperature sensitivity was investigated by modulated differential scanning calorimetry and surface water contact angle determination. The effects of initiator concentration, photoreduction time, monomer concentration and light exposure time on grafting rate are discussed. The results showed that graft-copolymer is temperature-sensitive hydrophilic/hydrophobic, and its low critical solubility temperature is around 33°C. The grafting rate could be increased by increasing the initiator concentration, monomer concentration, extending the photoreduction time and irradiation time; and the grafting rate could be controlled by adjusting these four factors.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Shuyue Yang,Dongmei Zhang,Jie Xu,Zongping Zhang,Shibing Ni
High theoretical capacity and safety performance endow Li 3 VO 4 with great promising as anode material for Li-ion batteries. However, approaches and inner mechanisms to advance the performance of Li 3 VO 4 are limited. Herein, we demonstrate for the first time, continuously-high pseudocapacitive charge storage triggered by N doped MXene in a Li 3 VO 4 -based electrode, resulting in excellent comprehensive electrochemical performance. The hybrid electrode delivers high discharge capacity of 515.2 mAh g −1 after 500 cycles at 0.1 A g −1 . After periodic rate performance test from 0.1 to 2.0 A g −1 for 410 cycles, the capacity of the hybrid electrode can be fully recovered. Followed by additional 1000 cycles at 0.5 A g −1 , the hybrid electrode still delivers high discharge capacity of 457.6 mAh g −1 . The robust capacitive charge storage induced by N doped MXene and the remarkable comprehensive electrochemical performance are referential for the design of high performance Li 3 VO 4 -based anode material, and the facile approach is beneficial for mass production toward practical application. Graphical abstract Download : Download high-res image (210KB) Download : Download full-size image N doped MXene induced robust pseudocapacitive charge storage in a Li 3 VO 4 electrode is firstly demonstrated responsible for the excellent comprehensive electrochemical performance.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Miao Zhang,Ruijin Zheng,Ying Ma,Ruiping Chen,Xun Sun,Xuan Sun
Three 2D N-rich COFs linked by –C=N– bond, named COF-SDU1, COF-SDU2, COF-SDU3, have been synthesized via the Schiff-base condensation reaction . Tri-(4-formacylphenoxy)-1,3,5-triazine (TRIF) is employed as N-rich aldehyde building block, and p-phenylenediamine (PA), hydrazine hydrate, and terephthalic dihydrazide (TPDH) are as the amine building blocks, respectively, which results in high crystallinity, high BET surface area, and abundant N-atom sites for COF-SDU1, COF-SDU2, and COF-SDU3. COF-SDU1 exhibits large CO 2 uptake of 741 mg g −1 at 298 K under 45 bar, while COF-SDU2 is 484 mg g −1 and COF-SDU3 is only 331 mg g −1 , which are closely related to their specific surface area but irrespective of the absolute N-content. The result clearly reveals the impact of various factors, including N-content, BET surface area and pore size on CO 2 storage performance. It shows that N-content determines capacities at low pressure (<1 bar), BET surface area plays the decisive role under relative low pressure (<25 bar) and large pore size helps enhance the capacity under relative high pressure (>25 bar). Among all factors, BET surface area plays the crucial role in determining the high-pressure CO 2 storage capacity, which is well verified by theoretical modeling.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xue Ma,Xin Dong,Baosheng Li,Qiuyue Zheng,Rui Li,Chaobo Huang,Lihua Huo,Xianfa Zhang,Xiaoli Cheng,Yingming Xu
n-Pentanol, a commonly used Volatile organic compounds (VOCs) in industry, is harmful to the environment security and human health. Thus, it is necessary to develop n-pentanol sensors. Herein, spherical (ZTO-S), cubic (ZTO-C) and pseudo-cubic (ZTO-PC) ZnSnO 3 were obtained by changing the ratio of solvent in hydrothermal/solvothermal process. By contrast, the ZTO-PC sensor had a high sensitivity of 135.2 to 100 ppm n-pentanol at 170 °C, a short response time of 0.8 s, and a low detection limit of 10 ppb. Meanwhile, the ZTO-PC sensor displayed superior reproducibility, good humidity resistance and excellent long-term stability. The outstanding sensing performance response of the ZTO-PC sensor is attribute to its high surface adsorbed oxygen content, fast electron mobility and good conductivity, providing abundant active sites and effective gas adsorption platform. In addition, the mechanism of the ZTO-PC sensor for n-pentanol was studied by XPS , GC-MS, and in-situ DRIFTS . After contact with ZnSnO 3 , n-pentanol was first oxidized to n-pentanal and then decomposed into CO 2 and H 2 O. This work well-designed three types of ZnSnO 3 through morphological engineering, providing a hopeful strategy for improving the gas sensitive performance.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Tiantian Fang,Xifan Chen,Changyu Yang,Yaqi Cao,Junshi Zhang,WenChao Peng,Yang Li,Fengbao Zhang,Xiaobin Fan
Smart hydrogels with good flexibility and biocompatibility have been widely used. The common near-infrared (NIR) photothermal agents are facing a trade-off between good photothermal-conversion efficiency and high biocompatibility. Therefore, developing new metal-free photothermal agents with low cost, high biocompatibility and excellent phase stability is still in urgent need. In this study, we successfully combined poly( N -isopropylacrylamide) (PNIPAM) with the two-dimensional (2D) silicene nanosheets via the in situ polymerization method. Attributed to the thermal-responsive nature of PNIPAM and the excellent photothermal properties of 2D silicene, the obtained silicene/PNIPAM composite hydrogels exhibited dual thermal and NIR responsive properties. This smart hydrogel showed rapid, reversible and repeatable NIR light-responsive behaviors. The volume of this smart hydrogels can shrink significantly under NIR irradiation and recover to its original size without the NIR irradiation. Remote near-infrared light-controlled microfluidic pipelines and electronic switches based on obtained silicene/PNIPAM composite hydrogels were also demonstrated. This work significantly broadens the application prospects of silicene-based hydrogels in remote light-controlled devices.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）