CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Lin Tan,Jing Han,Chuanwen Wang,Genwang Zhang,Huixia Feng,Nali Chen,Dan Zhao
Due to their physicochemical properties, the three-dimensional Metal-organic frameworks (MOFs) derived composites show great potential as electromagnetic wave (EMW) absorbers. However, poor impedance matching limits their actual EMW absorption performance. Composite materials that combine magnetic and dielectric losses offer a potential solution to enhance impedance match and significantly improve microwave absorption. In this work, a novel N,S-GS/Co/C composite was fabricated via a solvothermal method and a subsequent pyrolysis process to introducing nitrogen and sulfur co-doped graphene (N,S-GS) into Co-MOF. By co-doping nitrogen and sulfur, abundant defects and disordered sites were introduced on graphene, which stimulate interfacial polarization and dipole polarization. The minimum reflection loss (RL) of the sample obtained by pyrolysis at 600 °C is −68.8 dB at 9.7 GHz. Simultaneously, the thickness is 2.51 mm, and the effective absorption bandwidth (EAB) can reach 3.04 GHz. Its excellent EMW absorption performance is mainly attributed to interfacial polarization, multiple reflections, dipole polarization, magnetic resonance and eddy current loss. Accordingly, the N,S-GS/Co/C composite is convinced to be a competent candidate among EMW absorbers with high absorption intensity.
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高影响因子
BIOMACROMOLECULES
·
2021
·
IF 6.988
Shuai Zhu,Ruizhong Xue,Zikun Yu,Xu Zhang,Shifang Luan,Haoyu Tang
Poly(l-cysteine)s with methylthio pendants (PMTLCs) were synthesized by ring-opening polymerization of a new l-cysteine-based N-carboxyanhydride. The thioether bonds of PMTLC can be readily oxidized by H2O2 yielding water-soluble PMTLCOX. The methylthio groups can undergo an alkylation reaction using methyl iodide and a subsequent ion-exchange reaction yielding sulfonium-based polypeptides (PPLC-DMS-X, where X = I, BF4). PPLC-DMS-X showed upper critical solution temperature-type thermo- and oxidation-responsive properties in aqueous solutions. Both PMTLC and PPLC-DMS-X showed oxidation-induced β-sheet to α-helix transitions. The absorbance of PPLC-DMS-I and methyl orange aqueous solution displayed a significant linear correlation with temperature, which makes the sulfonium-based polypeptides good candidates in the field of temperature sensors.
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高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 17
·11025-11032
·
IF 12.732
Zhiwei Guo,Chunyang Bao,Xiaohan Wang,Xingyuan Lu,Haoxiang Sun,Xiang Li,Jian Li,Junqi Sun
Mechanically robust polyurethanes and polyureas with excellent healing and recycling capacities have an extended service life, and can reduce raw material consumption and environmental pollution. In this work, healable, recyclable and mechanically super-strong poly(urea-urethane)s (PUUs) are conveniently fabricated via cross-linking isocyanate-terminated poly(tetramethylene ether glycol) (PTMEG) with nitrogen-coordinated boroxines (NCBs). The tripodal NCBs generate three-dimensionally cross-linked PUUs (denoted as NCB-PUUs) with a high cross-linking density. Meanwhile, hydrogen bonds and phase-separated PTMEG segments can serve as physical cross-linkers to further strengthen NCB-PUUs. As a result, the NCB-PUUs exhibit a tensile strength of ∼47 MPa and a toughness of ∼190 MJ m−3. Because of the high reversibility of NCBs and hydrogen bonds, the NCB-PUUs are capable of efficiently healing and recycling at room temperature with the assistance of ethanol or a water/ethanol mixture to restore their original mechanical strength. NCB-PUUs can be conveniently deposited on solid surfaces by dip-coating and spraying methods to serve as protecting coatings. The NCB-PUU coatings have firm adhesion on solid surfaces and can be doped with organic dyes to display diverse colors. More importantly, the NCB-PUU coatings can heal deep and wide cuts and scratches for multiple times in a given region.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jingwen Zhang,Chuchu Cheng,FangShu Xing,Cheng Chen,Caijin Huang
Engineering semiconductor materials with vacancies and co-catalysts is a valid method to improve their photocatalytic performance. Herein, we prepared S vacancies-rich Mn 0.3 Cd 0.7 S nanorods modified with β-Ni(OH) 2 nanoparticles through solvothermal and co-precipitation strategies. The as-obtained 0D/1D β-Ni(OH) 2 /Mn 0.3 Cd 0.7 S nanorods exhibit excellent visible-light H 2 -production activity up to 71.09 mmol g −1 h −1 , 5.23 times higher than pure Mn 0.3 Cd 0.7 S and better than 1 wt% Pt/Mn 0.3 Cd 0.7 S and most reported Mn x Cd 1−x S-based catalysts. The apparent quantum yield reaches 46.68% at λ = 420 nm. We found that the presence of S vacancies and β-Ni(OH) 2 enhances the transfer/separation of photogenerated carriers and increases reaction sites, which is beneficial to photocatalytic H 2 -production reaction. This work proposes a new idea for the application of metal hydroxide co-catalysts and S vacancies in sulfide materials for photocatalytic H 2 production.
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高影响因子
CARBON
·
2021
·
IF 9.594
Yuanyuan Li,Lixue Gai,Guilin Song,Qingda An,Zuoyi Xiao,Shangru Zhai
CoS 2 /Cu 2 S embedded N/S co-doped mesh-like carbonaceous composites with enhanced electromagnetic wave absorbing performance was successfully prepared using carboxymethyl cellulose hydrogel spheres as starting materials by freeze-drying and high-temperature carbonization , in which thiourea as a source of N/S was favorably achieved. This newly designed three-dimensional mesh-like structures embedded with CoS 2 and Cu 2 S nanoparticles was confirmed by various techniques, while the N/S co-doped carbonaceous matrix, would contribute to the enhancement of electron transport , interfacial polarization , dipole polarization, ferromagnetic resonance, and magnetic coupling . This unique three-dimensional mesh structure facilitates multiple reflections and scattering of electromagnetic waves within the single matrix. By adjusting the dosage ratio between components and the filling amount of filler, the composite material exhibited a good impedance matching, which promotes the synergy between conductive loss, dielectric loss, and magnetic loss, and improves the electromagnetic wave loss. When the composite is filled with 25 wt%, there is a minimum reflection loss value of −51.68 dB at 5.20 GHz, and when the coating thickness is 4.5 mm, the effective absorption bandwidth is 3.84 GHz when the coating thickness reaches 2.0 mm. The experimental results illustrated that the synthesized composites might be alternative materials for low-frequency band electromagnetic wave absorption.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Tianyu Shi,Chenyuan Zhao,Yuxiang Zhou,Haihong Yin,Changqing Song,Lin Qin,Zhiliang Wang,Haibao Shao,Ke Yu
Lithium-sulfur batteries (LSBs) are regarded as promising candidates for next-generation electrochemical energy storage systems due to their low cost and high energy density . However, the insulative sulfur, the volume expansion and high soluble polysulfides are three roots impeding their practical applications, and consequently bring challenges of low sulfur utilization, poor cyclic stability and sluggish redox kinetics. Herein, a special core–shell ZnS-CNTs/S@Ni(OH) 2 (labeled as ZnS-CNTs/S@NH) cathode has been designed to overcome above obstacles and elevate the electrochemical performance . The ZnS-CNTs/S@NH cathode is synthesized via a facile step-by-step strategy, in which ZnS-decorated CNTs was used as a framework to load sulfur and followed with a ultrathin Ni(OH) 2 (NH) layer encapsulation. The ZnS-CNT core combines merits of CNT network and polar ZnS quantum dots (QDs), accommodating the volume change, offering efficient pathways for fast electron/ion transport, and anchoring polysulfides through polar interactions. The outer Ni(OH) 2 shell physically confines the active material and meanwhile provides plenty of catalytic sites for effective polysulfide chemisorption . Benefiting from these merits, the ZnS-CNTs/S@NH cathode exhibits excellent cell performances in comparison with ZnS-CNTs/S and CNTs/S. Its discharge capacity at different C-rates is optimal in the three cathodes, which decreases from 1037.0 mAh g −1 at 0.1 C to 646.1 mAh g −1 at 2.0 C. Its cyclic capacity also manifests the slowest reduction from 861.1 to 760.1 mAh g −1 after 150 cycles at 0.5 C, showing a high retention (88.3%) and a tiny average fading rate (0.078%). The strategy in this work provides a feasible approach to design and construct core–shell cathode materials for realizing practically usable Li–S batteries.
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高影响因子
Journal of Energy Chemistry
·
2021
·
IF 9.676
Zehui Fan,Chen Zhang,Wuxing Hua,Huan Li,Yan Jiao,Jingyi Xia,Chuan-Nan Geng,Rongwei Meng,Yingxin Liu,Quanjun Tang,Ziyang Lu,Tongxin Shang,Guowei Ling,Quan-Hong Yang
Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox reaction severely lowers the practical performance. The use of interlayer between the cathode and separator has been widely investigated to physically or chemically block the LiPSs, while the introduction of catalytic materials is a more effective strategy to accelerate the conversion of LiPSs. MXene with rich surface chemistry has shown its potential for facilitating the catalytic conversion, however, the aggregation of MXene sheets usually leads to the loss of the catalytic active sites. Herein, we report a diatomite/MXene (DE/MX) hybrid material as the bifunctional interlayer for improving the adsorption/conversion of LiPSs in Li-S batteries. The diatomite with porous structure and rich silica-hydroxyl functional groups could trap LiPSs effectively, while prevent the aggregation of MXene. The DE/MX based interlayer showed bifunctions of enhancing the chemical adsorption and promoting the conversion of LiPSs. The Li-S batteries with the DE/MX interlayer delivered an improved cycling stability with a low capacity decay of 0.059% per cycle over 1000 cycles at 1.0 C. Moreover, stable 200 cycles can be realized with a high sulfur loading electrode up to 6.0 mg cm −2 . This work provides an effective strategy to construct bifunctional interlayers for hindering the shuttling of LiPSs and boosting the practical application of Li-S batteries.
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高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Ke Zhang,Danqing Li,Qingyun Tian,Hongyang Cao,Farid Orudzhev,Irina A. Zvereva,Jingkun Xu,Chuanyi Wang
Practical application of photocatalysis is often challenged by some intrinsic issues such as recombination of photogenerated charge carriers, stability and separation, etc. Herein, bismuth decorated 0D/2D ZnFe 2 O 4 /Bi 5 FeTi 3 O 15 (Bi/ZF/BFT) step-scheme (S-scheme) heterojunction was fabricated by an in-situ method. Due to the advantages of structure and composition, the Bi/ZF/BFT with the desired proportion (Bi/ZF/BFT-35) exhibits favorable photocatalytic performance towards tetracycline (TC) degradation. Compared with the pure ZF, the nanohybrid shows superior stability after 5 times cycle tests. Moreover, Bi/ZF/BFT-35 is convenient to be separated from the reaction system due to its magnetic nature. As identified by ESR measurement, •O 2 − and •OH radicals were involved in the photodegradation of TC, which supports that the S-scheme is successfully prepared. Also, the Bi/ZF/BFT-35 shows great ability of chemical oxygen demand (COD) removal in the practical wastewater as well. Importantly, antibacterial activity against E. coli test indicates that photodegraded TC has lower biotoxicity. The present work demonstrates that cocatalyst Bi modified ZF/BFT S-scheme can not only significantly improve its stability with good recyclability from the reaction system, but also inhibits the recombination of charge carriers, giving insight on the strategy of fabricating a promising photocatalyst for practical wastewater treatment.
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高影响因子
MOLECULAR PHARMACEUTICS
·
2021
·
IF 4.939
Qi Zhang,Baolin Huang,Hongjiao Xue,Zimin Lin,Jie Zhao,Zheng Cai
(S)-carvedilol (S-CAR) is the dominant pharmacodynamic conformation of carvedilol, but its further development for extended-release formulation is restricted by its poor solubility. This study aimed to prepare and screen S-CAR salts that could be used to improve solubility and allow extended release. Five salts of S-CAR with well-known acid counterions (i.e., phosphate, hydrochloride, sulfate, fumarate, and tartrate) were produced using similar processes. However, these salts were obtained with water contents of 1.60–12.28%, and their physicochemical properties differed. The melting points of phosphate, hydrochloride, and tartrate were 1.1–1.5 times higher than that of the free base. The solubility of S-CAR salts was promoted to approximately 3–32 times higher than that of the free base at pH 5.0–8.0. Typical pH-dependent solubilities were evidently observed in S-CAR salts, but considerable differences in solubility properties among these salts were observed. S-CAR phosphate and hydrochloride possessed high melting points, considerable solubility, and excellent chemical and crystallographic stabilities. Accordingly, S-CAR phosphate and hydrochloride were chosen for further pharmacokinetic experiments and pharmaceutical study. S-CAR phosphate and hydrochloride extended-release capsules were prepared using HPMC K15 as the matrix and presented extended release in in vitro and in vivo evaluations. Results implied that water molecules in the hydrated salt were a potential threat to the achievement of crystal stability and thermostability. S-CAR phosphate and hydrochloride are suitable for further development of the extended-release formulation.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Zhenlin Ma,Rong Zheng,Yu Liu,Yulong Ying,Weidong Shi
Recently, carbon nanotubes (CNT)-based interconnected architectures exhibit promising prospects in supercapacitors due to their flexibility and high electrical conductivity. Herein, a three-dimensional (3D) interconnected network structure combined with conductive carbon nanotubes interpenetrating MOFs-derived Co-Ni-S composite spheres (Co-Ni-S/CNTs) was synthesized. Such 3D interconnected architecture significantly leads to a favorable electronic structure, fast charge-transfer capacity, and more pseudocapacitive. The Co-Ni-S/CNTs-based hybrid electrode exhibits an extraordinary specific capacitance of 540.6C g −1 at 1 A g −1 and competitive rate performance (capacity retention rate of 69.9% when the current density increases to 10 times). Subsequently, a hybrid supercapacitor is assembled using Co-Ni-S/CNTs as the positive electrode and commercial activated carbon as negative electrode. The device delivers a high energy density of 63.5 W h kg −1 at 800 W kg −1 and keeps 83.0% initial capacitance retention after 10,000 cycles. The encouraging performances demonstrate the significant contribution of the 3D interconnected architecture for the future energy storage.
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高影响因子
InfoMat
·
2021
·Vol. 3
·期 7
·790-803
·
IF 25.405
Yongshang Zhang,Peng Zhang,Shijie Zhang,Zheng Wang,Neng Li,S. Ravi P. Silva,Guosheng Shao
The realistic application of lithium–sulfur (Li–S) batteries has been severely hindered by the sluggish conversion kinetics of polysulfides (LiPS) and inhomogeneous deposition of Li 2 S at high sulfur loading and low electrolyte/sulfur ratio (E/S). Herein, a flexible Li–S battery architecture based on electrocatalyzed cathodes made of interfacial engineered TiC nanofibers and in situ grown vertical graphene are developed. Integrated 1D/2D heterostructured electrocatalysts are realized to enable highly improved Li + and electron transportation together with significantly enhanced affinity to LiPS, which effectively accelerate the conversion kinetics between sulfur species, and thus induce homogeneous deposition of Li 2 S in the catalyzed cathodes. Consequently, highly active electro-electrocatalysts-based cells exhibit remarkable rate capability at 2C with a high specific capacity of 971 mAh g −1 . Even at ultra-high sulfur loading and low E/S ratio, the battery still delivers a high areal capacity of 9.1 mAh cm −2 , with a flexible pouch cell being demonstrated to power a LED array at different bending angles with a high capacity over 100 cycles. This work puts forward a novel pathway for the rational design of effective nanofiber electrocatalysts for cathodes of high-performance Li–S batteries.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Xuefeng Li,Fanzhe Bu,Haiqiu Zhang,Chengji Zhao
After tethering sodium 2-mercaptoethanesulfonate (MTS) to the bromomethylated poly(arylene ether ketone) precursor, a novel clustered sulfonated poly(arylene ether ketone) containing flexible sulfoalkyl groups (MTSPAEK) was prepared and used as polymer electrolyte membrane for application in DMFCs. The chemical structure and the degree of grafting of MTSPAEK copolymers were identified by 1 H NMR spectra. The resulted MTSPAEK copolymers exhibited excellent thermal stability (T d5% > 259 °C) and good mechanical properties (tensile strength at break > 52 MPa). Compared to conventional sulfonated aromatic hydrocarbon polymers, MTSPAEK membranes displayed enhanced oxidative stability in Fenton's reagent owing to the elimination of free radicals by the sulfide groups located on the polymer side chains. Especially, MTSPAEK-2.10 with the highest content of flexible sulfoalkyl groups exhibited a highest proton conductivity of 0.181 S cm −1 at 80 °C. It could be attributed to the obvious hydrophilic/hydrophobic phase-separated structure within the membrane, which was confirmed by AFM images. Moreover, MTSPAEK-2.10 membrane performed a peak power density of 70 mW cm −2 in DMFC when feeding with 2 M methanol at 80 °C, which was comparable to the performance of recast Nafion as reported. Therefore, the combination of good thermal stability and mechanical properties, good oxidative stability, and good methanol barrier performance of MTSPAEK membranes indicated that they have potential to be alternative materials for PEMs in DMFCs.
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高影响因子
危险品化学品经营许可证（带存储）