ACS Nano
·
2023
·
IF 17.1
Shiyong Chu,Caoyang Shao,Jiaming Tian,Jingyang Wang,Yuan Rao,Chengrong Xu,Haoshen Zhou,Shaohua Guo
Layered oxides are widely accepted to be promising cathode candidate materials for K-ion batteries (KIBs) in terms of their rich raw materials and low price, while their further applications are restricted by sluggish kinetics and poor structural stability. Here, the high-entropy design concept is introduced into layered KIB cathodes to address the above issues, and an example of high-entropy layered K0.45Mn0.60Ni0.075Fe0.075Co0.075Ti0.10Cu0.05Mg0.025O2 (HE-KMO) is successfully prepared. Benefiting from the high-entropy oxide with multielement doping, the developed HE-KMO exhibits half-metallic oxide features with a narrow bandgap of 0.19 eV. Increased entropy can also reduce the surface energy of the {010} active facets, resulting in about 2.6 times more exposure of the {010} active facets of HE-KMO than the low-entropy K0.45MnO2 (KMO). Both can effectively improve the kinetics in terms of electron conduction and K+ diffusion. Furthermore, high entropy can inhibit space charge ordering during K+ (de)insertion, and the transition metal–oxygen covalent interaction of HE-KMO is also enhanced, leading to suppressed phase transition of HE-KMO in 1.5–4.2 V and better electrochemical stability of HE-KMO (average capacity drop of 0.20%, 200 cycles) than the low-entropy KMO (average capacity drop of 0.41%, 200 cycles) in the wide voltage window.
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高影响因子
FUEL
·
2023
·
IF 7.4
Deng Zhao,Haoyuan Feng,Yu Wang,Fei Wang,Huashan Wang,Hua Liu,Hui Liu
The influence mechanism of alkali metal potassium (K) on cellulose pyrolysis is a vague and fundamental key topic in the field of biomass thermal conversion. In this study, the pyrolysis of cellulose and K-impregnated cellulose was compared by in-situ DRIFTS (Diffused Reflectance Infrared Fourier Transform Spectroscopy) and TG (Thermal Gravimetric)–MS (Mass Spectrum) experiment, and quantum chemical calculations were used to verify the peak position and pyrolysis mechanism of infrared (IR) spectroscopy. Stepwise isothermal in-situ DRIFTS was designed to study the reaction path at high temperatures. It was found that in the early stage of pyrolysis, K accelerated the activation of cellulose by attacking the hydrogen bond (H-bond) in the crystal structure of cellulose, increased the dehydration rate between molecules, and promoted the decomposition of cellulose. Simultaneously, it weakened the epoxy–ether bond, inhibited the formation of dehydrated sugar, and promoted the formation of furan. Subsequently, K combined with carbonyl groups to form C–O–K structures, which improved the thermal stability of certain oxygen-containing functional groups such as carbonyls/aldehydes, so that these structures were retained until higher temperature. K promoted the conversion of dehydrated sugars to straight-chain ketones/aldehydes, which led to an increase in carbon conversion. During the coke generation stage, K promoted the formation of disordered carbon and residues, thereby inhibiting coke aromatization. The isothermal in-situ DRIFTS method proposed in this study was demonstrated to better inhibit the high temperature drift of IR spectrum during pyrolysis. It clarified the conversion between functional groups at high temperatures, which is expected to promote the development of other high-temperature pyrolysis mechanism.
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JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
·
2023
·Vol. 128
·期 24
·e2023JD039971
·
IF 4.4
Lanxiadi Chen,Soleil E. Worthy,Wenjun Gu,Allan K. Bertram,Mingjin Tang
Mineral dust is one of the most abundant types of ice nucleating particles in the atmosphere. During atmospheric transport, mineral dust particles can become coated with inorganic and organic solutes, which can impact their ice nucleation activity. Aminium cations formed from amines are one type of organic solute that can coat mineral dust particles in the atmosphere, but their effects on the ice nucleation activity of mineral dust have not been studied. We investigated the effects of primary, secondary, and tertiary aminium cations with methyl and ethyl groups, as well as ammonium cations, on the ice nucleation activity of K-feldspar, an important type of mineral dust, in the immersion freezing mode at low cation concentrations (0.2–20 mM) using a droplet-freezing apparatus. Ammonium cations substantially increased the ice nucleation activity of K-feldspar, consistent with previous studies. In contrast, primary aminium cations significantly reduced K-feldspar ice nucleation activity, and secondary and tertiary aminium cations had no significant effect (the effect was less than the uncertainty of our measurements). Our combined results are consistent with the following mechanisms: ammonium cations undergo ion exchange with K-feldspar, providing exposed N–H groups for hydrogen bonding with ice; primary aminium cations undergo ion exchange with K-feldspar, exposing a hydrophobic tail that is not effective at nucleating ice; secondary and tertiary aminium cations do not undergo ion exchange with K-feldspar due to steric effects caused by the multiple hydrophobic groups on the cation. Key Points Ammonium cations significantly increased the ice nucleation activity of K-feldspar Primary aminium cations substantially reduced the ice nucleation activity of K-feldspar Secondary and tertiary aminium had limited effects on the ice nucleation activity of K-feldspar due to their inability for ion exchange Plain Language Summary Ice nucleating particles are particles in the atmosphere that can initiate the formation of ice in liquid clouds, impacting cloud properties, precipitation, and climate. Mineral dust is a dominant type of ice nucleating particles in the atmosphere. During atmospheric transport, aminium cations, formed from amine gases which can be abundant in the atmosphere, can coat mineral dust particles altering their ability to nucleate ice. However, the effect of aminium cations on the ice nucleation ability of mineral dust particles has not been studied. We investigated the effects of aminium and ammonium cations on the ice nucleation ability of K-feldspar, an important type of mineral dust and ice nucleating particles in the atmosphere. Our results show that secondary and tertiary aminium cations have no effect on the ice nucleating ability of K-feldspar, but primary aminium cations greatly reduce the ice nucleating ability of K-feldspar. This has possible implications for predicting cloud formation in the atmosphere. We also present a mechanism related to ion exchange that can explain our ice nucleation results.
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Journal of Materiomics
·
2023
·
IF 9.4
Jian Guo,Xinrui Yang,Yulong Yang,Shuting Pang,Shan-Tao Zhang,Bin Yang
Ferroelectric Sr 0.6 Ba 0.4 Nb 2 O 6 (SBN) shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied. The presence of such structural vacancy provides the possibility to further modulate the crystal structure and electrical properties. In this work, alkali ions (Li + , Na + , K + ) doped SBN ceramics have been fabricated via solid-solution reaction method. In general, each doping promotes the crystal structure evolves from unfilled toward filled tungsten bronze. However, the different doping ion radius causes the differences in occupying initial structural vacancies, resulting in significantly different electrical properties, Li + doping enhances relaxor characteristic whereas Na + and K + doping lead to normal ferroelectric behavior, accompanying an increase in Curie temperature ( T c ) from 36 °C of SBN to 40, 212, 148 °C of Li + , Na + and K + doping, respectively. Benefiting from improved relaxor degree and high density, the Li + doped SBN displays a good energy storage performance. Since the ratio of Sr/Ba and (Sr + Ba)/Nb has not been changed, this work presents direct evidence for the effect of structural vacancy on crystal structure and properties, as well as inspiration for further work on unfilled tungsten bronze.
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Frontiers in Chemistry
·
2023
·
IF 5.5
Gao Bingliang,Liu Zhiwei,Deng Yifan
Al-Li alloy was prepared by electrodeposition on solid aluminum electrode in a urea-LiCl (77.5:22.5, mol%) molten salt system at 353–393 K. The results of cyclic voltammetry and chronopotentiometry show that underpotential deposition of Li occurs on the Al electrode and forms phases of Al(α) and AlLi(δ) which are confirmed by XRD measurements. Scanning electron microscopy observation of deposits indicates that Al-Li alloy with the thickness of 143 µm was obtained by potentiostatic electrolysis at −0.5 V vs. Li+/Li. The Li content in the alloy obtained at 373 K can reach 6.9 wt%. Galvanostatic electrolysis at 20 A demonstrated that Al-Li alloy coating on aluminum plate can be obtained from urea-LiCl electrolyte at 373 K in the atmosphere.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Fei Fu,Xuan Zhou,Minggui Shen,Dan Wang,Xu Xu,Shibin Shang,Zhanqian Song,Jie Song
With the development of high-frequency communication, the miniaturization of integrated circuits (ICs) has led to interconnected signal delays and losses. The dielectric properties of epoxy resins are no longer satisfactory, because of the presence of polar groups. Herein, a benzocyclobutene-rosin modifier was designed and synthesized to reduce the dielectric constant of epoxy resins. The recross-linking network of benzocyclobutene inhibits the polarizability of the polar groups, and rosin skeletons increase the free volume of epoxy resins. Consequently, the dielectric constant of epoxy resins decreased from 3.12 to 2.72 and their water absorption decreased from 1.06% to 0.861%. The dielectric constant and water absorption are lower than those of most commercial dielectric materials. Additionally, the adhesion of epoxy resins was improved, which broke the contradiction between the dielectric properties and the adhesion of traditional epoxy resins. The modified epoxy resin was finally applied to printed circuit boards. At 15 GHz, its signal loss was 28.8 dB, which was lower than that of a commercial epoxy resin (FR-4), demonstrating that the modified epoxy resin can better meet the miniaturization needs of ICs.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Zhihao Su,Jionghao Huang,Runhao Wang,Yi Zhang,Lingxing Zeng,Yufei Zhang,Haosen Fan
Covalent organic frameworks (COFs) are regarded as the potential and promising anode materials for potassium ion batteries (PIBs) on account of their robust and porous crystalline structure. In this work, multilayer structural COF connected by double functional groups, including imine and amidogent through a simple solvothermal process, have been successfully synthesized. The multilayer structure of COF can provide fast charge transfer and combine the merits of imine (the restraint of irreversible dissolution) and amidogent (the supply of more active sites). It presents superior potassium storage performance, including the high reversible capacity of 229.5 mAh g −1 at 0.2 A g −1 and outstanding cycling stability of 106.1 mAh g −1 at the high current density of 5.0 A g −1 after 2000 cycles, which is superior to the individual COF. The structural advantages of the covalent organic framework linking by double functional groups ( d -COF) can develop a new road for that COF anode material for PIBs in further research.
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高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 5
·950-958
·
IF 7.779
Shifei Kang,Zhihao Zhang,Maofen He,Zirou Fang,Di Sun,Lulu Zheng,Xijiang Chang,Lifeng Cui
Co-modification of graphitic carbon nitride (g-C3N4) photocatalysts can maximally optimize their intrinsic photoelectric structures, but usually involves complex multistep reactions, and thus is challenging because structural collapse and active site decay usually happen due to the complex process, over-treatment or conflict of different modification strategies. In this work, potassium iodate (KIO3), an edible salt additive, was used as a critical waste-free modifier in the thermal polymerization of g-C3N4, leading to a fast and coordinated co-modification of g-C3N4 photocatalysts. The final g-CN-KIO3 photocatalyst demonstrated a superior and balanced optical absorption ability and semiconductor band structure. In visible-light-driven photocatalytic model tests, g-CN-KIO3 showed a 3.25 times higher Cr(VI) photoreduction rate and five orders of magnitude lower residual bacteria in a photocatalytic sterilization within 120 min compared with raw g-C3N4. The photocatalytic performance of g-CN-KIO3 also outperformed all of the controls without maximized K–I–O co-modification (CN-K, CN-I, CN-O, and CN-KI). Photocurrent and electrochemical impedance experiments suggest that the co-modified photocatalysts have a faster charge separation ability, which is attributed to the multiple K–I–O co-modifications inducing an optimized surface electronic structure and slower carrier recombination. This work provides a new way to simplify and coordinate complex multi-factor regulation of materials.
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Antibiotics-Basel
·
2022
·Vol. 11
·期 2
·162
·
IF 5.222
Xia Xiao,Quanmin Huan,Yanhu Huang,Yuan Liu,Ruichao Li,Xilan Xu,Zhiqiang Wang
Tigecycline (TIG) is one of the last effective options against multidrug resistance bacteria. Recently, the RND (resistance–nodulation–division) efflux pump gene cluster,tmexCD1-toprJ1, and the tetracycline-efflux pumptet(A) mutation were reported to mediate high level resistance to TIG in clinically important pathogens, weakening the efficacy of TIG. In this study, we report the potent synergistic effect of the antidiabetic drug metformin in combination with TIG againsttet(A) mutant andtmexCD1-toprJ1positiveK. pneumoniae. The fractional inhibitory concentration index (FICI) of TIG and metformin were less than 0.05 for all the tested isolates. The time–kill curve assay showed that the combination of TIG and metformin exhibited much better antimicrobial effect than TIG alone. The synergistic effect was also confirmed in vivo using a well-studiedGalleria mellonellalarvae model. Mechanistic studies demonstrated that metformin disrupted the important component of proton motive force, the electric potential (Δψ) and the function of efflux pump, thereby increasing the intracellular concentration of TIG. This finding revealed that metformin might be a possible adjuvant of TIG for combating with superbugs carrying thetet(A) mutant andtmexCD1-toprJ1genes.Keywords:tigcycline;metformin;tmexCD1-toprJ1;tet(A);synergy
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高影响因子
BIOMACROMOLECULES
·
2022
·
IF 6.978
Fei Fu,Minggui Shen,Dan Wang,He Liu,Shibin Shang,Fei-Long Hu,Zhanqian Song,Jie Song
Low-k dielectrics are urgently needed in modern integrated circuits. The introduction of free volume instead of porous structures has become a powerful strategy to reduce the k value. According to this strategy, the biomass resource rosin-containing hydrogenated phenanthrene ring was introduced into benzocyclobutene (BCB) resin to reduce the k value; then a rosin-based BCB monomer was successfully synthesized. Meanwhile, the BCB monomer without a rosin skeleton was prepared. After converting the monomers into thermo-crosslinked materials, notably that the rosin skeleton has a great influence on the free volume and k value of the material. The fractional free volume and k value of the former are 26% and 2.44, respectively, and those of the latter are 14% and 2.84, respectively. In addition, the distances between molecular chains and the density of the former are 0.60 nm and 1.06 g cm–3, respectively; those of the latter are 0.56 nm and 1.28 g cm–3, respectively. These data show that introducing hydrogenated phenanthrene rings occupies part of the space and hinders the packing of molecular chains, which increases the distance between molecular chains and reduces the density of the polymer, resulting in an increasing free volume and a reducing k value. Notably that introducing hydrogenated phenanthrene rings cannot affect other properties of the material. Therefore, this research indicates that introducing rosin skeletons can prepare high-performance materials, which provide some promising low-k materials for the development of electronics and microelectronics.
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高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Xiao-Qiong Li,Xiang-Nan Liu,Yi-Lei Jia,Xi-Liang Luo,Hong-Yuan Chen,Jing-Juan Xu
Lysosomal acidification is essential for its degradative function, and the flux of H+ correlated with that of K+ in lysosomes. However, there is little research on their correlation due to the lack of probes that can simultaneously image these two ions. To deeply understand the role of K+ in lysosomal acidification, here, we designed and fabricated a nanodevice using a K+-aptamer and two pH-triggered nanoswitches incorporated into a DNA triangular prism (DTP) as a dual signal response platform to simultaneously visualize K+ and pH in lysosomes by a fluorescence method. This strategy could conveniently integrate two signal recognition modules into one probe, so as to achieve the goal of sensitive detection of two kinds of signals in the same time and space, which is suitable for the detection of various signals with the correlation of concentration. By co-imaging both K+ and H+ in lysosomes, we found that the efflux of K+ was accompanied by a decrease of pH, which is of great value in understanding lysosomal acidification. Moreover, this strategy also has broad prospects as a versatile optical sensing platform for multiplexed analysis of other biomolecules in living cells.
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高影响因子
CARBON
·
2021
·
IF 9.594
Xiang Gao,Wei Liu,Tianqi Wang,Jingrou Dai,Yuanyuan Pan,Yongxu Du,Yongpeng Cui,Hongguang Fan,Shuang Liu,Yongcheng Jin
N-doping can endow carbon materials with high electrochemical activity. Besides the widely validated sp 2 -hybridized nitrogen doping, sp -hybridized nitrogen ( sp - N ) atoms are also expected to be new active sites. However, both sp - N atoms and cyano (CN) groups containing sp - N are rarely produced in carbon materials presently. In this work, the first cyano groups-modified carbon materials are synthesized firstly via an interesting struggle between the chemical etching of KOH and the catalytic graphitization of Co nanoparticles in carbon frameworks. The theoretical calculations and experimental results manifest that the stronger electronegativity of CN groups renders carbon materials a higher electrochemical activity. As K + storage anodes, the CN − modified carbon materials exhibit an obvious boost in potassium storage performance in both ester- and ether-based electrolytes. Therefore, as a new N doping form, the successful introduction of CN groups into carbon materials opens a door for exploring sp -N doped carbon materials for applications in energy storage and other fields.
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