Molecular Catalysis
·
2020
·
IF 3.687
Kaikai Liu,Tiefeng Wang,Minghan Han
The catalytic isomerization of 2-methyl-3-butenenitrile (2M3BN), a model reaction in the DuPont process, has been performed using NiL 4 (L=tri- O - p -tolyl phosphite) as a catalyst. The lowered catalytic activity in the isomerization with coexistence of 2-pentenenitrile (2PN) and 2-methyl-2-butenenitrile (2M2BN) indicates that both 2PN and 2M2BN are the catalyst inhibitors , and the quantitative relationship between the conversion of 2M3BN and the content of 2M2BN and 2PN is provided. DFT calculation results suggest that the inhibition effect is attributed to the generation of dead-end intermediates (2PN)NiL 2 and (2M2BN)NiL 2 , both of which take nickel atom out of the catalytic cycle in the isomerization process. To suppress the inhibition effect, new catalytic intermediates are rationally designed based on their computational %V bur . An efficient method that adding extra ligand 1, 5-bis(diphenylphosphino)pentane (dppp5) to the NiL 4 catalyst is selected experimentally. Compared to the results obtained with NiL 4 as catalyst, the (dppp5)NiL 2 increases the conversion of 2M3BN from 74.5 % to 93.4 % at 3 h of reaction and provides a high selectivity to 3PN (> 98 %) at optimal conditions.
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Journal of Materials Chemistry B
·
2020
·Vol. 8
·期 41
·9601-9609
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IF 5.344
Xia Li,Jianpeng Li,Sijia Hao,Ailing Han,Yayu Yang,Xiaoyu Luo,Guozhen Fang,Jifeng Liu,Shuo Wang
Enzyme mimics have been developed by imitating and incorporating specific features of native enzymes to achieve catalytic activity, and are expectedly comparable to that of native enzymes. Here, inspired by the “catalytic triad” in serine proteases, a series of peptide-based enzyme mimics were designed to follow the rational design principle of peptides via self-assembly, and were further applied in the degradation of di(2-ethylhexyl)phthalate (DEHP). The relationship of the structure of enzyme mimics with their degradation activity was analyzed by transmission electron microscopy, fluorescence spectroscopy, circular dichroism, Raman spectroscopy, X-ray diffraction spectroscopy, and computational modeling. These results show that the hydrophobic skeleton, amino acid sequence, species, and periodic distribution have important effects on the structure of the peptide sequence and the number of hydrogen bonds; in addition, pH can also affect the self-assembly characteristics of peptides and the formation of stable fibers, which are all closely linked to the catalytic activity of the enzyme mimics. The self-assembled peptides had a stable fibrous morphology and secondary structure after the DEHP degradation assay. The enzyme mimics with high catalytic activity constructed from the self-assembled peptides may provide guidance for the future degradation of DEHP in food packaging or water treatment, and also give insights into the design of enzyme mimics in other related fields.
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高影响因子
Materials Research Express
·
2020
·Vol. 7
·期 10
·105304
·
IF 1.929
Yuanji Xiao,Xinqian Yang,Xinjian Cheng,Shuangyu Xiong,Rong Chen
Among nitroaromatic compounds with similar structures, 2,4,6-trinitrophenol (TNP) exhibits strong biological toxicity and explosion hazard. Therefore, detection of TNP is of great importance. In this work, two novel fluorescent macromolecular chemosensors P1 and P2 were prepared using boron-dipyrromethene (BODIPY) as the fluorophore. After the preparation of small BODIPY molecule M1, another small molecule M2 with two aldehyde groups was synthesized by two consecutive Vilsmeier-Haack reactions. Then, M2 reacts with trans-cyclohexane-1,4-diamine and 1,4-phenylenediamine respectively to obtain two macromolecules P1 and P2 via Schiff Base forming reaction. The results suggested that P1 and P2 could recognize TNP only while other aromatic/nitroaromatic compounds cannot cause significant fluorescence intensity response. When TNP exist, these fluorescent macromolecular chemosensors produce significant fluorescence quenching. At the same time, because the electron-rich Schiff base and the electron-deficient TNP have the structural basis of chemical interaction, these two macromolecular sensors also have excellent sensitivity to TNP, and the excellent recognition limit of detection reach as low as 0.017 μM. High sensitivity and selectivity have been applied to test TNP in lake water samples as well.
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JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Guanglu Li,Chang Liu,Zhao Zhang,Baihua Cui,Yanan Chen,Yida Deng,Wenbin Hu
Oxygen evolution and oxygen reduction are considered as essential processes in the energy conversion devices. The progress of cost-effective bifunctional catalysts has become a critical issue to be solved. Here, we report that Co(OH) 2 @N-doped carbon (NC) was facilely synthesized through the impregnation strategy of metal-organic frameworks derived carbon and cobalt ions. N-doped carbon with porous structure and cobalt hydroxide nanosheets play a synergistic effect role, representing excellent catalytic performance toward oxygen evolution and reduction reactions. The obtained Co(OH )2 @NC exhibits remarkable activity in terms of a lower overpotential of 330 mV@10 mA cm −2 for OER and a more positive half-wave potential (E 1/2 = 0.84 V) for ORR in alkaline medium, outperforming IrO 2 and Pt/C. Due to its superior bifunctional catalytic performance, Co(OH) 2 @NC catalyst is applied into a promising air electrode of Zn-air battery. This presented strategy of impregnation synthesis in this work provides a new design direction for practical electrochemical energy devices.
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高影响因子
ACS Applied Materials & Interfaces
·
2020
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IF 8.758
Xianshu Qiao,Hongjun Kang,Yang Li,Kai Cui,Xin Jia,Henghao Liu,Wei Qin,Max Pupucevski,Gang Wu
We report a highly efficient and stable electrode composed of a porous Fe-doped β-nickel hydroxide nanopyramid array supported on nickel foam (U–Fe-β-Ni(OH)2/NF) for overall water splitting. The unique structure is assembled via a self-templated strategy by utilizing the FeNi oxalate (FeNi–C2O4/NF) nanopyramid as the templates, followed by an anion-exchange reaction at room temperature. Due to the intrinsic activity of Fe-doped β-Ni(OH)2 along with unique porous array structures consisting of two-dimensional (2D) active materials on three-dimensional (3D) conductive substrates, the developed electrode exhibited outstanding electrocatalytic activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in an alkaline medium. The introduced amount of Fe plays a significant role in promoting OER and HER activity compared to the β-Ni(OH)2 electrode. The optimal electrode (U–Fe-β-Ni(OH)2/NF-2) generated a current density of 10 mA cm–2 at low overpotentials of 218 mV for the OER and 121 mV for the HER. The electrode also demonstrated considerably stable performance during the continuous water splitting process. Furthermore, we elucidated the promotion mechanisms of the active Fe-doped β-Ni(OH)2 compound for the OER and HER based on extensive characterization and electrochemical measurements. Hence, this work provides a facile approach to developing low-cost, efficient, and stable hydroxide-based electrodes for bifunctional OER and HER in water splitting.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 10
·4092-4098
·
IF 3.288
Yu-wei Liu,Ping Wang,Jun Wang,Bo Xu,Jin Xu,Jiu-gang Yuan,Yuan-yuan Yu,Qiang Wang
Poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels with high transparency and excellent mechanical properties are fabricated via in situ free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) in mixtures of water and 1-butyl-3-methylimidazolium chloride (BmimCl) followed by the exchange of BmimCl with water. Compared with the PHEMA hydrogels prepared without BmimCl, the obtained hydrogels display a denser and more homogeneous microstructure, which contributes to their highly transparent appearance and outstanding mechanical properties. The hydrogels could achieve elongation at break and tensile strength up to 705% and 173 kPa, respectively, at swollen equilibrium states. Furthermore, the hydrogels also reveal fast recovery in water after circle elongation, showing anti-fatigue properties owing to their quick reformation of hydrogen bonds between polymer chains. More importantly, the hydrogels are able to retain considerable mechanical strength in water over a wide pH range (1 to 13) due to their stable cross-linking structures. It is believed that this novel type of transparent PHEMA hydrogel exhibiting outstanding mechanical properties, superior stability and anti-fatigue properties would find extensive applications in biomedical and industrial fields.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
·
IF 3.99
Bin Yan,Ji Lan,Yueshan Li,Yinjie Peng,Lingying Shi,Rong Ran
In this paper, hexagonal Ni(OH) 2 nanosheets were prepared by hydrothermal method with nickel chloride hexahydrate as matrix and ammonia as precipitant. The lateral size of Ni(OH) 2 nanosheets was about 100–250 nm. The structure of the Ni(OH) 2 sheets was characterized by XRD , SEM , IR, TGA etc. Pickering emulsion was prepared by using Ni(OH) 2 nanosheets as stabilizer and dichloromethane (DCM) as oil phase. Furthermore, the stability factors of Pickering emulsion and the adsorption of Congo red (CR) on interface particle layer were studied. The adsorption equilibrium of CR was analyzed by Langmuir adsorption model and Freundlich adsorption model, and the adsorption process was researched by pseudo-first-order kinetics and pseudo-second-order kinetics. Compared with Ni(OH) 2 in the water phase, the Ni(OH) 2 in interface particle layer exhibited a much higher adsorption capacity and a faster deposition rate . The adsorption mechanism of CR can be mainly attributed to electrostatic interaction between the positively charged interface particle layer and the anionic CR molecules. It can be expected that as a promising adsorbent for CR removal in water treatment, the Ni(OH) 2 sheets in Pickering interface layer can provide a new strategy for dye adsorption.
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JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2020
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IF 5.647
Shuo Li,Jia Liu,Tianwei Tan,Jiapei Nie,Huili Zhang
To reduce the emission of greenhouse gases, the substitution of fossil fuel by renewable energy sources is increasingly important. Matching energy supply and demand is however required, even more so if intermittent renewable energy sources are employed. Thermal energy storage then offers significant advantages. Thermo-chemical energy storage systems, using reversible reactions, have a high reaction enthalpy that exceeds the storage capacities of sensible and latent heat modes. Magnesium hydroxide is a candidate TCES material for such a system at temperature around 300 °C, and adaptable when doping Mg(OH) 2 with metal salts. Both pure Mg(OH) 2 and its composites with 1, 3, 6 and 10 wt% LiNO 3 are studied. The present work validates this TCES process and develops reaction rate equations needed for its design. The LiNO 3- doping significantly reduces the onset temperature of dehydration. For pure Mg(OH) 2 , the temperature is 325 °C. It is reduced to 289 °C when 1 wt% LiNO 3 is present, and further reduced to 269 °C at a dosage of 10 wt% LiNO 3 . Whereas the dehydration of pure Mg(OH) 2 is slow, with a rate constant k of 1.72 10 −5 s −1 at 300 °C, adding increasing amounts of LiNO 3 progressively increases the reaction rate constant to ~10 −2 s −1 at 300 °C when 10 wt% LiNO 3 is present. The kinetic expressions enable to predict the conversion yield and amount of heat stored or released for any desired temperature and selected duration of the heat-induced dehydration. LiNO 3- doped Mg(OH) 2 have a high potential in TCES applications when the heat source is available at temperatures between 250 and 400 °C, since the equilibrium temperature and the extent of de-hydration Mg(OH) 2 can be tuned to the required temperature range by adding different wt% of LiNO 3 .
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CHINESE CHEMICAL LETTERS
·
2021
·
IF 6.779
Min Xie,Chaobo Huang,Yongqi Liang,Shuang Li,Liping Sheng,Yi Cao
MoS 2 nanosheets (NSs) are novel 2D nanomaterials (NMs) with potential uses in many areas, and therefore oral exposure route to MoS 2 NSs is plausible. Currently, MoS 2 NSs are considered as biocompatible NMs , but there is lacking of systemic investigations to study the interactions of MoS 2 NSs with intestinal cells. In this study, we exposed the 3D Caco-2 spheroids to MoS 2 NSs or MoS 2 powders (denoted as MoS 2 -bulk), and investigated the potential adverse effects of MoS 2 -materials based on transcriptomics and lipidomics analysis. As expected, both MoS 2 NSs and MoS 2 -bulk were dose-dependently internalized into 3D Caco-2 spheroids but did not induce cytotoxicity, membrane disruption or decrease of thiols. However, the Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis indicated that nutrient absorption and metabolism was decreased. One of the most significantly decreased KEGG pathways is fat digestion and absorption (map04975), and Western blotting analysis further showed that fatty acid binding protein 1 and apolipoprotein A1 , key proteins involved in fat digestion and absorption, were down-regulated by MoS 2 NSs or MoS 2 -bulk. In addition, BODIPY 493/503 staining suggested that exposure to MoS 2 NSs and MoS 2 -bulk decreased lipid levels in the spheroids. However, lipidomics data indicated that MoS 2 materials only decreased 8 lipid classes, including lysophosphatidylcholine , lysodimethylphosphatidylethanolamine, N -acylethanolamine, ceramide phosphoethanolamines , gangliosides , lysosphingomyelin and sulfatide, whereas most of the lipid classes were indeed increased. In addition, MoS 2 NSs was more potent to decrease the lipid classes compared with MoS 2 -bulk. Combined, the results from this study showed that MoS 2 NSs and bulk materials were non-cytotoxic but altered lipid profiles in 3D Caco-2 spheroids.
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高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Liangjun Zhou,Wenxi Wang,Dekang Xu,Zhenyu Wang,Zhibin Yi,Min Wang,Zhouguang Lu
Thermal quenching of luminescence is the most critical problem for rare earth doped phosphors used in light-emitting diodes (LEDs). Herein, we demonstrate that thermal quenching can be considerably suppressed via the negative thermal expansion effect in Zr(WO 4 ) 2 that serves as host for Eu 3+ red emission. The photoluminescence (PL) intensity is surprisingly enhanced by 130% when the temperature is raised from room temperature to 100 °C. As temperature further increases to 160 °C, the PL intensity turns to reduce, which is still 1.4 times of that at room-temperature. Moreover, Zr(WO 4 ) 2 :15%Eu phosphor has good durability, which still exhibits strong red luminescence (only 13% loss) after being kept in 85 °C/85% relative humidity chamber for 240 h. The anti-thermal quenching of Eu 3+ luminescence can be ascribed mainly to the following two factors: first one is the thermal-enhanced energy transfer between Eu 3+ ions induced by the contraction of Zr(WO 4 ) 2 unit-cell volume that leads to the strong structural rigidity of host lattice; second one would be electron traps in the host that favors the increase of electrons on the excited energy levels. This important anti-thermal quenching effect induced from the negative thermal expansion of the host matrix may stimulates a novel and efficient approach to design highly thermal stable phosphors for next-generation LEDs.
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RSC Advances
·
2021
·Vol. 11
·期 53
·33626-33636
·
IF 3.361
Leliang Wu,Yiting Lin,Yimin Zhang,Peng Wang,Mingjun Ding,Minghua Nie,Caixia Yan,Shiyao Chen
Alkaline substances could activate peroxymonosulfate (PMS) for the removal of organic pollutants, but relatively high alkali consumption is generally required, which can cause too high pH of the solution after the reaction and lead to secondary pollution. Within this study, PMS activated by a relatively low dosage of Ca(OH)2 (1 mM) exhibited excellent efficiency in the removal of bisphenol S (BPS). The pH of the solution declined to almost neutral (pH = 8.2) during the reaction period and conformed to the direct emission standards (pH = 6–9). In a typical case, BPS was completely degraded within 240 min and followed the kinetics of pseudo-first-order. The degradation efficiency of BPS depended on the operating parameters, such as the Ca(OH)2, PMS and BPS dosages, initial solution pH, reaction temperature, co-existing anions, humic acid (HA), and water matrices. Quenching experiments were performed to verify that singlet oxygen (1O2) and superoxide radicals (O2˙−) were the predominant ROS. Degradation of BPS has been significantly accelerated as the temperature increased. Furthermore, degradation of BPS could be maintained at a high level across a broad range of pH values (5.3–11.15). The SO4−, NO3− did not significantly impact the degradation of BPS, however, both HCO3− and HA inhibited oxidation of BPS by the Ca(OH)2/PMS system, and Cl− had a dual-edged sword effect on BPS degradation. In addition, based on the 4 identified intermediates, 3 pathways of BPS degradation were proposed. The degradation of BPS was lower in domestic wastewater compared to other naturals waters and ultrapure; nevertheless, up to 75.86%, 77.94% and 81.48% of BPS was degraded in domestic wastewater, Yaohu Lake water and Poyang Lake water, respectively. Finally, phenolic chemicals and antibiotics, including bisphenol A, norfloxacin, lomefloxacin hydrochloride, and sulfadiazine could also be efficiently removed via the Ca(OH)2/PMS system.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Hang-bo Zheng,Yu-ling Li,Yuan-li Wang,Feng Ma,Peng-zhao Gao,Wen-ming Guo,Hang Qin,Xiao-pan Liu,Han-ning Xiao
The development of efficient, inexpensive, and stable hydrogen evolution reaction (HER) electrocatalysts is the key to large-scale water electrolysis technologies for hydrogen production. Constructing heterojunction electrocatalysts has become one of the effective strategies for designing high-performance HER electrocatalysts due to their unique heterogeneous interfaces. Herein, a new strategy of PH 3 assisted synthesis of metaphosphate is reported, which is used to construct Co(PO 3 ) 2 @NPC/MoS 2 heterostructures (where NPC is N-doped porous carbon). The results show that the formation of Co(PO 3 ) 2 @NPC/MoS 2 heterogeneous interfaces can optimize the electronic structure of the electrocatalyst and greatly improve its HER performance. As a result, a lower overpotential of 119 mV at 10 mA cm −2 is obtained in alkaline electrolyte . This work provides a new perspective for the design of high-performance electrocatalysts for electrocatalytic water splitting.
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