INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 19
·11256
·
IF 6.208
Bo Xu,Yanting Liu,Simiao Wei,Siheng Zhao,Lijun Qian,Yajun Chen,Hao Shan,Qinglei Zhang
A phosphorous-based bi-functional compound HPDAl was used as a reactive-type flame retardant (FR) in an epoxy thermoset (EP) aiming to improve the flame retardant efficiency of phosphorus-based compounds. HPDAl, consisting of two different P-groups of aluminum phosphinate (AHP) and phosphophenanthrene (DOPO) with different phosphorous chemical environments and thus exerting different FR actions, exhibited an intramolecular P-P groups synergy and possessed superior flame-retardant efficiency compared with DOPO or AHP alone or the physical combination of DOPO/AHP in EP. Adding 2 wt.% HPDAl made EP composites acquire a LOI value of 32.3%, pass a UL94 V-0 rating with a blowing-out effect, and exhibit a decrease in the heat/smoke release. The flame retardant modes of action of HPDAl were confirmed by the experiments of the scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetry–Fourier transform infrared spectroscopy–gas chromatograph/mass spectrometer (TG-FTIR-GC/MS). The results indicate that the phosphorous-based FRs show different influences on the flame retardancy of composites, mainly depending on their chemical structures. HPDAl had a flame inhibition effect in the gas phase and a charring effect in the condensed phase, with a well-balanced distribution of P content in the gas/condensed phase. Furthermore, the addition of HPDAl hardly impaired the mechanical properties of the matrix due to the link by chemical bonds between them.Keywords:flame retardant;intramolecular P-P synergy;aluminum phosphinate;phosphophenanthrene;epoxy resin
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Surfaces and Interfaces
·
2022
·
IF 6.137
Changjin Xu,Yinglei Liu,Baljeet Singh,Shiyuan Yi,Gaowu Qin,Song Li
Interfacial local environment of noble metal nanoparticles (NPs) and support is crucial for the development and design of thermally and chemically stable noble metal heterogeneous catalysts. The unique chemical environment can strengthen the NPs interaction with the support surface, which can effectively avoid the agglomeration of NPs . The strategy is developed to modulate the interfacial chemical environment of supported Pt NPs with the help of the unsaturated Al 3+ in Al 2 O 3 N (nanobelt) support, resulting in a sintering-resistant Pt/Al 2 O 3 N catalyst. Al solid-state MAS NMR characterization shows that Al 2 O 3 N support contains a large amount of unsaturated Al penta 3 + (about 22.6%). XAS confirms that Pt NPs deposited on the surface of Al 2 O 3 with rich unsaturated pentahedral coordinated Al 3+ sites have a unique coordination structure at the interface (more Pt-O coordination). When catalyzing the CO oxidation as a probe reaction, the catalytic activity and the particle sizes of Pt NPs do not change significantly even after the reaction at 400 °C for 15 days, and the complete CO conversion temperature increases only by 40 °C when the catalyst is screened at 600 °C for 5 days. This work demonstrates a new strategy to develop stable large-scale anti-sintering noble metal-based heterogeneous catalysts for many important high-temperature industrial applications.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
ACS Omega
·
2025
·
IF 4.3
Yujie Wen,Fang Wang,Heqing Zhu,Changju Yang,Xiaokang Ke,Wei Li,Hua Huo,Luming Peng
Noble metal oxides are highly valuable and act as a key component of metal-oxide interfaces in oxide-supported noble metal catalysts, which play a crucial role in modern industrial society. Here, we investigate the structure of four common and stable noble metal oxides using 17O solid-state NMR. The optimal isotopic labeling temperature ensures the highest labeling efficiency while preserving the structure of the oxides. The variation in characteristic signals for each noble metal oxide reveals oxygen species in different chemical environments, while the NMR parameters related to chemical shift anisotropy and quadrupolar interaction obtained from spectral fitting indicate more structural information. DFT calculations are used to assist spectral assignments for various oxygen species. This work serves as a prerequisite for studying solid-state NMR of oxide-supported noble metal catalysts.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Jingjie Luo,Enhui Qu,Yixue Zhou,Yanan Dong,Changhai Liang
Rhenium , although viewed as one of the noble metals with lower-price, has been commonly used as doping element in the bimetallic catalysts due to its middlebrow to activate hydrogen. Its major role as catalyst is less frequently mentioned. In this work, rhenium has been decorated on the surface of activated carbon and used for the selective hydrogenation of dimethyl 1, 4-cyclohexanedicarboxylate (DMCD) to 1, 4-cyclohexanedimethanol (CHDM). Characterizations suggested that ReO x particles were anchored occupying the surface oxygenated groups on pre-functionalized carbon. Rhenium decoration modified both the textural and chemical properties of the samples. Electrons were easily transferred from Re to the neighboring C atoms as a result of the formation of fine ReO x particles. Medium strong acid sites were generated and rhenium species in the reduced states could be still maintained under appropriate rhenium dispersion. The moderate hydrogenation ability of rhenium catalyst partially restrained the excessive hydrogenation of CHDM to other by-products. Rational decoration of 5 wt% Re performed the better catalytic performance with complete conversion of diester and 66 % yield of diol. The specific rate reached 9.5 × 10 2 m m o l D M C D ∙ g R e - 1 ∙ h - 1 at 220 °C under 10 MPa H 2 .
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2015
·
IF 1.766
Xijia He,Xuhui Xu,Dacheng Zhou,Cuiqiong Yan,Jianbei Qiu
The copper (Cu) atoms were incorporated into the bismuth (Bi) doped silicate glasses by the copper for sodium (Cu–Na) ion exchange method. After the ion exchange process, the Cu ions were introduced into the glass matrix with different copper valence states, namely, Cu 0 , Cu + , and Cu 2 + . Bi 3 + ions could be reduced to lower valence states of Bi containing Bi near infrared (NIR) active centers with the incorporation of the Cu ions, resulting in the enhancement of the Bi NIR luminescence intensity. During the heat treatment process, some lower valence states of Bi containing Bi NIR active centers could be oxidized, resulting in the attenuation of the NIR luminescence of Bi. Our research may extend the understanding of chemical environment modulation in Bi valence states and offer a valuable way to enhance the NIR luminescence intensity of Bi in glasses.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Geomechanics for Energy and the Environment
·
2023
·
IF 5.1
Jing Chen,Manman Hu
During the operation of hydraulic fracturing as used in many geo-energy and geo-environment applications, chemical stimulation is often incorporated for cracking enhancement in low-permeability geological formations for the purpose of an optimization of energy recovery. The mechanism of subcritical crack propagation in a chemically reactive environment is essential for understanding of the involved coupled chemo-mechanical process and a better control of acid-assisted hydraulic fracturing. It has been postulated that the rate of crack propagation under environmental loads is inherited from the chemical processes involved including the reaction and the diffusive transport. However, laboratory explorations focusing on the evolving interplay between the propagation of a fluid-pressurizing individual crack and the environment it is subject to via a variable chemical intensity imposed have been rare. Here we present an experimental investigation on a single tensile crack propagation in alginate hydrogel as an analogue material for brittle rocks, driven by the injection of a chemically reactive fluid kept at constant pressure using a Hele-Shaw cell setup. We show that an intensified chemical environment can accelerate tensile crack propagation in both subcritical crack growth and fracturing regimes, while leading to the Region III fracturing of less brittle characteristics. During the experiment, crack-tip blunting upon injection of reactive solutions was observed, suggesting a competing mechanism between the crack-tip geometry induced toughening and the chemically induced softening within the process zone as the crack advances. Our results provide quantitative insights into how a chemically reactive environment facilitates the growth of a single macroscopic crack of mode I opening in a low-permeability matrix through coupled chemo-mechanical feedback. The imposed chemical environment promotes crack propagation while alleviating the stress concentration at the advancing crack tip, suggesting a more energy-efficient method compared to pure water fracturing. We anticipate our experimental investigation presented here to be a starting point of sound laboratory support for future studies towards a more controllable technique of chemical stimulation in geomaterials as well as complementing the ongoing modeling efforts in reactive chemo-mechanics.
研究领域:
地质力学
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2012
·
IF 2.474
Zhujian Huang,Pingxiao Wu,Xing Zhang,Xiaorong Wang,Nengwu Zhu,Jinhua Wu,Ping Li
In this study, intercalation of Fe(III) complexes [Fe(Ox) 3 ] 3− and [Fe(Cit) 2 ] 3− in Mg 2 Al layered double hydroxides (LDHs) had been carried out by different routes: direct self-assembly, reconstruction and anion exchange. The result of XRD indicated that these two kinds of Fe(III) complexes intercalated LDHs (LDHs/Fe-complexes) could be successfully synthesized by anion exchange obtaining two well crystallized LDHs both with a large basal spacing. The chemical environment of iron ion in the intercalated Fe complexes was determined by FTIR , XPS and XAFS, the results of which concertedly proved that the intercalated Fe complexes were well preserved in the interlayer of LDHs. The arrangement of the Fe(III) complexes anions in the galleries of LDHs was studied by one-dimensional electron density projection. The results showed that the [Fe(Ox) 3 ] 3− anions were probably accommodated in the gallery of LDHs as an interdigitated bilayer arrangement, and the [Fe(Cit) 2 ] 3− were perpendicularly arranged against the LDHs sheets. Through the research, it is proved that the obtained LDHs/Fe-complexes markedly enhanced the UV–vis absorption ability of Fe complexes.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Man Yang,Shuhao Qin,Youchang Yang,Mingmi Wu,Ting Lei,Yufei Liu,Huiju Shao
Owing to the global transition toward carbon neutrality, lithium-ion batteries (LIBs) are experiencing unprecedented demand growth as key energy storage components. A contact-electro-catalysis (CEC) method has been utilized in recycling spent LIBs for some time due to the process economy, efficiency and environmental sustainability. However, systematic investigations into the effects of the microstructure and surface chemical environment of dielectric materials on their catalytic activity in the CEC process remain scarce. Here, we demonstrated that the metal leaching efficiency simultaneously depended on the size and porous structure of SiO2 microspheres. Appropriate size and narrow distribution could dominantly diminish the scattering intensity of ultrasonic waves to gather energy and then facilitate the formation of cavitation bubbles to generate abundant electrons and radicals. Similarly, the porous structure also promoted the generation of electrons and radicals by enhancing aqueous-phase contact interfaces. Moreover, we manipulated the surface chemical environment of porous SiO2 microspheres by incorporating sodium alginate (SA) and polyethyleneimine (PEI). Hydroxyl, carboxyl and amino groups and –COO−/–NH3+-microstructures not only accelerated electron transfer from water molecules to SiO2 microspheres, inducing hydroxyl radicals, but also boosted electron transfer from SiO2 microspheres to O2, generating superoxide radicals. Consequently, under the experimental conditions established in this study, approximately 100% leaching efficiency of metals in the spent ternary cathode was achieved in 8 h at 80 °C due to the synergistic effect of hydroxyl and superoxide radicals. We anticipate this innovative strategy will significantly expand the applicability of CEC in LIB recycling, thereby addressing the growing global demand for sustainable LIBs.
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Tianliang Xie,Litao Han,Liangli Chu,Mingtao Han,Yue Jian,JinJin Chi,Xinyi Zhong,Tong Liu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yuena Meng,Yafang Qi,Sixin Wu
Insufficient selenization and uneven distribution of elements caused by the poor diffusion and reaction activity of selenium clusters is one of the main issues limiting the efficiency of Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells. Here, this work designs a simple and feasible strategy to improve the activity of selenium (Se) by implementing high-temperature treatment on graphite boxes loaded with Se pellets. The rapid adsorption/desorption characteristics of graphite on active gaseous small-molecule selenium have successfully introduced hyperactive Se 4 , Se 3 , and Se 2 into the selenization process. The results indicate that the adsorbed non-toxic gaseous active Se 3 and Se 4 can quickly and uniformly diffuse into the precursor film at low temperatures, thereby inducing nucleation and grain growth at both surface and back interface simultaneously, which inhibits the upward migration and aggregation of cations, especially Cu, and promotes the homogenization of elements. The overall relatively Cu-poor chemical environment suppresses the formation of Cu Zn defects and [2Cu Zn +Sn Zn ] defect clusters, and also promotes the generation of favorable V Cu . The band tail states and non-radiative recombination are then optimized. Finally, the CZTSSe solar cells achieve a power conversion efficiency (PCE) of 14.5%, with V OC / V OC SQ of 67% being one of the highest in the literature.
研究领域:
材料科学
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太阳能
·
半导体物理
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Yusheng Gao,Aiqun Kong,Mao Peng,Ye Lv,Menghui Liu,Wei Li,Jinli Zhang,Yan Fu
It is particularly challengeable to achieve C=O selectivity for Pd catalysts in thermal catalytic hydrogenation of cinnamaldehyde (CAL). This work offers a new electrochemical strategy that enables an unexpected switch toward C=O bond for CAL hydrogenation, based on the specific interaction between CAL and electrolyte-modulated Pd surface. Under galvanostatic electrolysis, guanosine 5′-monophosphate-modulated Pd electrode affords a record cinnamyl alcohol (COL) selectivity of 90.3% in neutral catholyte with no sacrifice of CAL conversion, showing the faradaic efficiency of 68.2%. It is of great interest to find that the aromatic moiety of CAL determines the preferential activation toward C=O bond over Pd surface under electric field. It is reported for the first time that selective hydrogenation of α, β-unsaturated aldehydes can be altered by electrochemical environment located between Pd electrode and surrounding electrolyte involving alkali cation along with organic solvent.
研究领域:
电化学
·
催化
·
有机化学
✓ 已验证
DOI
高影响因子
Energy Storage Materials
·
2021
·
IF 17.789
Xiaoya Gao,Zicheng Zuo,Fan Wang,Qian Chang,Houhe Pan,Liang Li,Feng He,Yuliang Li
Low-strain nanoarchitectures are the precondition for offering a stable electrochemical environment towards high-performance lithium-ion battery anode in the compaction system. Realizing the zero-strain for each particle of high-capacity anode is a scientific challenge, because of huge volume changes arising during the insertion/extraction process of Li + . Herein, we develop a facile and general strategy to construct a freestanding transition metal oxides (TMOs) anode with consecutive nanoarrays of yolk-shell nanorods . By confining the dehydration process in the ion-selective carbon-ene‑yne (CEY) nanotubes , free space can be precisely created for alleviating the excessive volume expansion of internal particles. The all-carbon CEY not only conducts the electrons and supports the nanoarchitecture of the anode, but also provides the high-areal-density atomic-level selective channels for Li + diffusion and prevents the electrolyte from decomposition. The as-obtained strainless anode demonstrates an ultra-stable architecture and interface during cycling, leading to a high specific capacity and enhanced cycling ability. Our result demonstrates the significant advantages to largely produce zero-strain architecture, towards ideally solving the crucial issues confronted in the high-volume-change electrode.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 38
·17999-18009
·
IF 3.3
Jinghua Yu,Yueling Guo,Yajie Dai,Ziren Jin,Zhiqian Wang,Fanghui Wang,Hong Zhu
A coated polypyrrole modified carbon carrier material was prepared by low-temperature oxidation in situ polymerization, which improved the defects, such as impurities on the surface, low functionalization, and easy corrosion in a harsh electrochemical environment, of traditional carbon carriers. The modification of polypyrrole onto the traditional carbon carriers was confirmed using techniques, such as TEM, FTIR, XPS, and SEM. The results showed that when the amount of pyrrole was 0.4 mL, the mass and specific activity of Pt3Cu/C@PPy catalyst were 0.45 A mgPt−1 and 0.51 mA cmPt−2, respectively, which are 3.2 and 4.7 times higher than those of the JM Pt/C catalyst. Compared with the Pt3Cu/C catalyst without polypyrrole modification, the modified catalyst also exhibited higher catalytic activity, electrochemical durability, and higher battery power than the JM Pt/C catalyst. The coating of polypyrrole on the carbon carrier can protect the carbon carrier from corrosion, effectively disperse and anchor the metal particles, and enhance the interaction between the metal and the carrier, thereby improving the catalytic activity.
研究领域:
材料科学
·
电化学
·
催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）