CATALYSIS LETTERS
·
2021
·Vol. 152
·期 4
·1170-1181
·
IF 3.186
Zhang Xilun,Liu Lin,Feng Ji,Ju Xiaohua,Wang Jiemin,He Teng,Chen Ping
Abstract Development of efficient catalysts for ammonia decomposition is crucial for hydrogen production from ammonia. Herein, Ru nanoparticles (NPs) highly dispersed on Pr 2 O 3 (Ru/Pr 2 O 3 ) were prepared and investigated as catalyst for ammonia decomposition reaction. Under relatively high weight hourly space velocity (WHSV = 30,000 mL g cat −1 h −1 ), the Ru/Pr 2 O 3 achieves a H 2 production rate of 20.9 mmol g cat −1 min −1 at 450 °C, which is superior to Ru/Pr 6 O 11 and many other typical oxides supported Ru catalysts. Detailed characterization results demonstrate that Pr 2 O 3 has high density of basic sites, abundant oxygen vacancies, and strong interaction with Ru, which can modulate electronic properties of Ru NPs and enhance the intrinsic activity of the catalyst, making the catalyst highly active for ammonia decomposition. Moreover, the Ru/Pr 2 O 3 catalyst also exhibits excellent stability and can maintain its high activity for over 100 h. The use of Pr 2 O 3 as support offers opportunity to improve the catalytic performance of Ru-based catalysts for ammonia decomposition. Graphic Abstract
The high density of basic sites, abundant oxygen vacancies of Pr 2 O 3 , and the strong metal–support interaction effectively promote the electron donation to Ru nanoparticles, enabling the superior catalytic performance of Ru/Pr 2 O 3 for ammonia decomposition.
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RSC Advances
·
2021
·Vol. 11
·期 30
·18448-18457
·
IF 3.361
Ying Zhao,Xi He,Han Wang,Jiufu Zhu,Huimin Wang,Yan Zheng,Song Zhu,Zhanchen Cui
Hydrolysis resistance is essential to the durability of the dentin bonding interface. Urushiol is a natural monomer that has been used in different fields over thousands of years but has the disadvantage of a long drying time. In this study, we evaluated a novel photocurable derivative of urushiol as the main monomer for polymerization in dentin adhesive and its effect on hydrolysis resistance. The derivative was characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. Compared with the Adper Single Bond 2, the experimentally synthesized adhesives had higher contact angles. In particular, the water sorption/solubility of the experimental samples were significantly lower than that of Adper Single Bond 2. The microtensile bond strengths of the test groups were higher than that of the control group, even after 5000 thermocycles. Cytotoxicity test results showed that adhesives based on the original derivative induced low toxicity to L929 cells. The results of this study may shift the focus of future research to natural monomers and even their derivatives which may perform well in dentistry.
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NANOTECHNOLOGY
·
2021
·Vol. 32
·期 26
·265603
·
IF 3.874
Jianwei Zheng,Liying Zhang,Yang Li,Hong-Bin Sun,Gang Zhang,Qi Sun
Core–shell nanocomposites with a catalytic metal-organic framework (MOF) shell are more effective and stable than bare MOF. We have successfully designed an effective heterogeneous catalyst for the synthesis of benzimidazole by integrating acidic catalytic activity, and promoted the aerobic oxidation and magnetic recyclability of core–shell nanocomposite Fe3O4@SiO2@UiO-66. The Fe3O4@SiO2 core is encapsulated by the in situ-grown UiO-66 shell, and the UiO-66 shell retains the porous structure and crystallinity of UiO-66 with abundant exposed Lewis acid sites. It shows high catalytic ability for the synthesis of various benzimidazoles through the acid-catalyzed condensation and aerobic oxidation with in situ oxygen. The Fe3O4@SiO2 core provides magnetic recyclability of Fe3O4@SiO2@UiO-66, and maintains high catalytic ability and stability over six cycles.
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CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Rong Wang,Qingfu Cai,Yunyang Zhu,Zhen Mi,Weijun Weng,Yicheng Liu,Jiaxun Wan,Jianhua Hu,Changchun Wang,Dong Yang,Jia Guo
Low-bandgap covalent organic frameworks (COFs) emerge as one of the most intriguing conjugated polymers for the development of electronic devices, while they often lack desirable electron affinity, thereby compromising the activity and stability in electrochemical transformation. Here, we report an n-type semiconducting two-dimensional (2D) COF, featuring a low bandgap (1.36 eV) and strong electron affinity (4.41 eV) as well as high crystallinity and porosity. The columnar stacking array of the benzobisthiadiazole moiety in 2D COFs plays a critical role in elevating electroactivity. It not only leads to the outstanding electrical conductivity and air stability upon reductive doping but also enables the boost of transformation kinetics for polysulfides on the separators of lithium–sulfur batteries causing a higher capacity and better cycling performance. The design strategy underpins the versatile development of electroactive COF materials with desirable electronic properties and promotes their applicability in energy storage and electronics.
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Nano Energy
·
2021
·
IF 17.881
Wei Xu,Jiayi Yang,Shuangshuang Liu,Yan Meng,Di Feng,Lingjie Jia,Sida Liu,Baolong Wang,Xiuhan Li
Liquid-solid triboelectric nanogenerator (LS-TENG) has emerged as a powerful tool in energy harvesting and motion detecting. There is a recognized need for improving the power output and signal-to-noise ratio of LS-TENG. The instantaneous discharging mechanism of LS-TENG is studied and experimentally realized by a controllable switch structure in this paper. The peak short circuit current and peak power output (at 1 MΩ) are increased by over 26 and 1700 times, respectively, with respect to the control LS-TENG working in the single electrode mode. This research provides a fresh insight in designing sensors with high signal-to-noise ratio and energy harvestors that have a superior performance in driving devices with low load resistance.
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JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2021
·Vol. 51
·期 5
·803-814
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IF 2.8
Zhao Ting,Jiang Liang,Liu Jinwei,Wu Hanqiang,Qin Na,Qian Linmao
Potassium persulfate was used as an effective oxidizer for chemical mechanical polishing (CMP) of GCr15 steel. The effects of pH, potassium persulfate content and chelating agents on the CMP performance of GCr15 steel were investigated, and the surface films formed in the potassium persulfate-based slurries were characterized accordingly. It is revealed experimentally that, with pH increasing from 2.0 to 9.0, the material removal rate (MRR) is independent of pH while the surface roughness R a decreases. At pH 8.0, as the potassium persulfate content increases, the MRR linearly increases with a slope of 48 nm min −1 mM −1 , but the surface quality continues to deteriorate accompanied with the black Fe 3 O 4 residue due to the severe corrosion by persulfate. In particular, Fe 2+ and Fe 3+ ions are continuously produced by oxidation of persulfate, and a significant part of Fe 2+ and Fe 3+ further reacts with OH − to form a non-uniform and rough surface film which primarily consists of Fe 3 O 4 . After adding an appropriate chelating agent EDTA, the R a reaches 1.7 nm without any black residue due to the chelation reactions between iron ions and EDTA. The findings suggest that a nano-precision surface finish of bearing steel could be achieved at weakly alkaline pH with persulfate-based slurries. Graphic abstract
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JOURNAL OF BIOLOGICAL CHEMISTRY
·
2021
·Vol. 297
·期 1
·
IF 5.157
Yi Zhang,Hai-Tao Ding,Wen-Xin Jiang,Xia Zhang,Hai-Yan Cao,Jing-Ping Wang,Chun-Yang Li,Feng Huang,Xi-Ying Zhang,Xiu-Lan Chen,Yu-Zhong Zhang,Ping-Yi Li
SGNH-type acetyl xylan esterases (AcXEs) play important roles in marine and terrestrial xylan degradation, which are necessary for removing acetyl side groups from xylan. However, only a few cold-adapted AcXEs have been reported, and the underlying mechanisms for their cold adaptation are still unknown because of the lack of structural information. Here, a cold-adapted AcXE, AlAXEase, from the Arctic marine bacterium Arcticibacterium luteifluviistationis SM1504T was characterized. AlAXEase could deacetylate xylooligosaccharides and xylan, which, together with its homologs, indicates a novel SGNH-type carbohydrate esterase family. AlAXEase showed the highest activity at 30 °C and retained over 70% activity at 0 °C but had unusual thermostability with a Tm value of 56 °C. To explain the cold adaption mechanism of AlAXEase, we next solved its crystal structure. AlAXEase has similar noncovalent stabilizing interactions to its mesophilic counterpart at the monomer level and forms stable tetramers in solutions, which may explain its high thermostability. However, a long loop containing the catalytic residues Asp200 and His203 in AlAXEase was found to be flexible because of the reduced stabilizing hydrophobic interactions and increased destabilizing asparagine and lysine residues, leading to a highly flexible active site. Structural and enzyme kinetic analyses combined with molecular dynamics simulations at different temperatures revealed that the flexible catalytic loop contributes to the cold adaptation of AlAXEase by modulating the distance between the catalytic His203 in this loop and the nucleophilic Ser32. This study reveals a new cold adaption strategy adopted by the thermostable AlAXEase, shedding light on the cold adaption mechanisms of AcXEs.
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CELLULOSE
·
2021
·Vol. 28
·期 10
·6481-6498
·
IF 5.044
Lang Daning,Shi Ming,Xu Xia,He Shixue,Yang Chao,Wang Lu,Wu Ronglan,Wang Wei,Wang Jide
Abstract 4-Nitrophenol is a highly toxic environmental pollutant. It is a challenge to selectively remove it from a mixture of various pollutants. Herein, we report a study on the selective adsorption of 4-nitrophenol by using molecularly imprinted polymers (MIPs). The imprinted polymer was synthesized using cellulose as a framework, onto which, the complex of the imprinting molecule (i.e., 4-nitrophenol) and a candidate material [namely, 2-(dimethylamino)ethyl methacrylate. DMAEMA] was grafted. The obtained MIP showed an excellent adsorption capacity with good selectivity. Also, the adsorption of 4-nitrophenol by the obtained MIP was fast and the adsorbent exhibited good recyclability. The thermodynamics and kinetics of the adsorption process of 4-nitrophenol by MIP was thoroughly studied, where an otherwise-equivalent non-imprinted polymer was used as a control in the experiments. The selectivity of the MIP adsorbent for 4-niteophenol was evaluated by two types of experiments: (1) adsorption experiments in single-component adsorbate systems (containing 4-nitrophenol, 3-nitrophenol, catechol, or hydroquinone), and (2) competitive adsorption experiments in binary adsorbate systems (containing 4-nitrophenol plus either 3-nitrophenol, catechol or hydroquinone). The selectivity coefficient for 4-nitrophenols was twice of those of other phenols (that were all around 2), indicative of the extent of the affinity of MIPs to these phenolic compounds. The recyclability of the adsorbent was evaluated for 5 adsorption–desorption cycles, where the adsorption capacity of the last cycle remained over 90.2% of that of the first cycle. Graphic Abstract
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Song Ma,Yanzheng Ji,Yongjie Dong,Siqi Chen,Yingjie Wang,Shaoyu Lü
Stimulus-responsive pesticide or fertilizer systems have been emerged to improve the use efficiency of agrochemicals , reduce over-application and ensuing environmental problems. However, environmental-friendly synthesis of these systems still remain challenging. In this work, an environmental-friendly synthesis strategy has been developed to form a pesticide and fertilizer combination to achieve the integration of plant protection and nutrient supply. This pesticide-fertilizer combination system was fabricated using ammonium zinc phosphate (ZNP) and in-situ synthesized zeolitic imidazolate framework-8 (ZIF-8) as nutrients resources, and dinotefuran (DNF) as a pesticide. DNF was encapsulated in-situ (loading capacity of 12.32 ± 0.46%) during the ZIF-8 crystal synthesis process, rather than loaded by further adsorption, which improved its stability and prevented premature or rapid release. The hydrophobic ZIF-8 provided a pH-responsive slow-release behavior. The cumulative released DNF within seven days at pH 4.0, 7.0 and 10.0 was 66.30%, 40.41%, and 37.44%, respectively. The pesticide-fertilizer combination system showed significant effects on corn seed pre-cultivation, soil cultivation and pest control. This work provides a strategy for the integration of pesticide and fertilizer, which will reduce negative environmental effects caused by their over-applications and have great potential in modern sustainable agriculture.
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Inorganic Chemistry Frontiers
·
2021
·Vol. 8
·期 17
·4035-4043
·
IF 6.569
Ruxin Liu,Wenjun Zhang,Guojing Li,Wenjing Liu
Advanced anti-counterfeiting materials have great research significance in the fields of economy, safety and human health. Compared with independent color mixed anti-counterfeiting materials, ultraviolet (UV) excitation wavelength-dependent discoloration, which can realize the change of the emission peak shape and color under different excitation wavelengths, is more attractive. In this work, the Sb-doped Cs2ZrCl6 vacancy-ordered double perovskite was designed and synthesized for anti-counterfeiting materials. Due to the singlet and triplet transitions of Sb3+ ions and self-trapping exciton (STE) emission of the Cs2ZrCl6 host, the material showed emission variability from blue to orange-yellow color. In addition, room temperature synthesis and excellent air and humidity stability further enhanced the potential of Sb-doped Cs2ZrCl6 for application.
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ENERGY & FUELS
·
2021
·
IF 3.605
Congsu Niu,Lianyuan Ji,Yao Chen,Shuai Ma,Yiwei Zhang,Xiaomin Liu,Hui Yang
Sodium–metal chloride batteries are usually operated at a relatively high temperature (270–350 °C) to achieve adequate electrochemical performance. Such a high operating temperature may cause several issues and limit their widespread applications. Lowering the operating temperature may alleviate these issues, which can be achieved by reducing the ohmic resistance of a Na−β″-Al2O3 solid electrolyte (BASE) and incorporating a low-melting-point catholyte. Herein, a planar sodium–copper chloride battery is evaluated at intermediate temperatures (from 100 to 175 °C) with a thin BASE disk (500 μm) and a room-temperature ionic liquid (RTIL). The RTILs at various concentrations (0.1–0.75 mol L–1) are prepared by dissolving different amounts of sodium bis(trifluoromethanesulfon)imide (NaTFSI) into 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][TFSI]) and used as the catholyte. The effect of NaTFSI addition in [EMIm][TFSI] on the physical properties of the catholyte is examined. With 0.5 mol L–1 NaTFSI in [EMIm][TFSI] ionic liquid to assemble the Na/CuCl2 battery, the fabricated cell delivers a capacity up to 146.5 mAh g–1 when cycled at 175 °C with the current density of 2 mA cm–2 and retains 94.5% capacity after 20 cycles. Moreover, the battery can run steadily at 130 °C and show a reversible capacity of 79.2 mAh g–1 when the operation temperature is set as low as 100 °C. To the best of our knowledge, these are the lowest operation temperatures reported thus far for sodium–metal-chloride-based cells.
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Molecular Catalysis
·
2021
·
IF 5.062
Xiao Li,Liusha Li,Tingting Qin,Gong Gun,Tiejun Lin,Liangshu Zhong
Tandem hydroaminomethylation is an efficient and green route for one-pot synthesis of amines directly from olefins. Herein, heterogeneous hydroxyapatite (HAP) supported single-atom Rh catalyst was prepared and used for tandem hydroaminomethylation of olefins. Characterization techniques confirmed the atomic dispersion of Rh species on HAP. Up to 99% conversion of 1-hexene with high selectivity to the desired amines (93.2%) was obtained over 0.5Rh 1 /HAP catalyst. Mechanism study demonstrated that the first hydroformylation step during the tandem catalytic process was rate-determining. Compared with the Rh nanoparticles on other oxide supports (Mg 3 Al, MgO and Al 2 O 3 ), the atomically dispersed Rh sites on HAP ensured the high hydroformylation activity, thereby guaranteed the outstanding catalytic performance for the total tandem process. Furthermore, various corresponding amines can be obtained with satisfactory yields over 0.5Rh 1 /HAP catalyst from a wide scope of olefins or amines substrates.
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