MICROCHEMICAL JOURNAL
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2020
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IF 3.594
Xuejian Xing,Li Huang,Shaojing Zhao,Jiafu Xiao,Minhuan Lan
S,N-doped carbon dots (S,N-CDs) were facilely prepared via a hydrothermal method by using thiourea and citric acid (CA) as precursors. The as-prepared S,N-CDs exhibited high stability in aqueous solution and were applied for fluorometric detection of tetracyclines (TCs). The approach was developed on the basic of the fluorescence of S,N-CDs at 440 nm, which was selectively quenched by TCs through the inner filter effect (IFE) mechanism. Moreover, the fluorescence of TCs with maximum at 600 nm could be used as the internal standard signal, resulting in a fluorometric spectral response. The limit of detection (LOD) was 0.25, 0.39 and 0.26 μM for tetracycline (TC), doxycycline (DC) and oxytetracycline (OTC), respectively. Furthermore, S,N-CDs were successfully utilized for the detection of residual TCs in fish and pork samples with acceptable recovery and good RSD.
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高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 22
·期 3
·742-752
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IF 9.405
Xiwei Hu,Xun Sun,Qiang Song,Yangyang Zhu,Yu Long,Zhengping Dong
Metal-free carbon catalysts with excellent catalytic performance have drawn much research attention recently. Herein, polymer-derived N,S co-doped carbon catalysts (PDNSC-X) with a hierarchically porous structure were facilely prepared by a cost-effective and convenient strategy via carbonization of a N- and S atom-containing polymer precursor and were subsequently used as efficient metal-free catalysts. The catalytic activity of the as-fabricated PDNSC-800 was greater than those of other reported heteroatom-doped carbon catalysts in catalytic reduction of various nitroarenes. The high catalytic activity of PDNSC-800 was related to the synergistic effects of a high surface area, a hierarchically porous structure, abundant N- and S-containing active sites, and defect formation. In addition, the close relationship between the N species (especially pyrrolic N) and high selectivity in metal-free catalytic synthesis was investigated in the reduction of nitroarenes and selective oxidation of ethylbenzene. This study may provide a new strategy to fabricate specific heteroatom-doped metal-free carbon catalysts for environmentally friendly efficient organic transformation.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Shizong Wang,Jianlong Wang
High efficient and stable activator is desired for the sulfate radical-based wastewater treatment. Cobalt sulfide and cobalt oxide have high catalytic activity for peroxymonosulfate (PMS), but poor stability. Here, a novel composite, nano Co 9 S 8 and CoO encapsulated by nitrogen and sulfur co-doped sludge-derived biochar (CoO/Co 9 S 8 @N-S-BC) was synthesized, characterized and applied for activating PMS. The results showed that CoO/Co 9 S 8 @N-S-BC can effectively activate PMS for sulfamethoxazole (SMX) degradation, and 0.08 mM of SMX could be completely degraded within 10 min. The influencing factors, such as pH, temperature, chloridion, carbonate and humic acid were investigated. The SMX degradation conformed to pseudo first-order kinetics with rate constant of 0.379 min −1 . Sulfate radicals (dominant) and hydroxyl radicals contributed to SMX degradation. Carbon defects, pyridinic N, quaternary N, the carbon atoms next to pyridinic N, C O groups, -C-S-C and Co(II), all contributed to PMS activation.
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高影响因子
Carbon Letters
·
2023
·
IF 4.5
Yang Yang,Hu Huali,Ai Jixing,Wang Hong,Du Haijun
Sulfamonomethoxine (SMM) is widely used to inhibit Gram-positive and Gram-negative bacteria, and improper use of SMM is detrimental to human health and ecological stability. Therefore, a sensitive determination method is of great importance for monitoring SMM residues in water, meat, milk, eggs, etc. Herein, a Pt-functionalized S-doped graphitic carbon nitride (Pt/S-g-C 3 N 4 ) was constructed for the electrochemical determination of SMM. The as-developed Pt 3 /S 3 -g-C 3 N 4 sensor showed a significant SMM determination performance. The electrochemical oxidation of SMM on Pt 3 /S 3 -g-C 3 N 4 /GCE involves two electron transference and was limited by a diffusion process. The as-developed Pt 3 /S 3 -g-C 3 N 4 /GCE sensor has good linearity in a wide range of 0.1–120 μmol/L and a remarkably low limit of detection (LOD) of 0.026 μmol/L for SMM determination. In addition, the sensor has high selectivity and anti-interference properties for SMM detection. Furthermore, this Pt 3 /S 3 -g-C 3 N 4 /GCE sensor has good reproducibility and stability. Moreover, the recoveries were in the range of 89.6–112.2% for the detection of the SMM in a real sample of egg. The proposed Pt 3 /S 3 -g-C 3 N 4 /GCE sensor shows great potential for practical applications in detecting trace amounts of antibiotics.
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高影响因子
CARBON
·
2015
·
IF 6.196
Feng Wu,Lili Shi,Daobin Mu,Hongliang Xu,Borong Wu
A novel hierarchical structure carbon/sulfur composite is presented based on carbon fiber matrices, which are synthesized by electrospinning. The fibers are constituted with hollow graphitized carbon spheres formed using catalytic Ni nano-particles as hard templates. Sulfur is loaded to the carbon substrates via thermal vaporization. The structure and composition of the hierarchical carbon fiber/S composite are characterized with X-ray diffraction, scanning electron microscopy, transmission electron microscopy , Raman spectroscopy , and nitrogen adsorption isotherms . The electrochemical performance is evaluated by cyclic voltammetry and galvanostatic charge–discharge. The results exhibit an initial discharge capacity of 845 mA h g −1 at 0.25 C (420 mA g −1 ), with a retention of 77% after 100 cycles. A discharge capacity of 533 mA h g −1 is still attainable when the rate is up to 1.0 C. The good cycling performance and rate capability are contributed to the uniform dispersion of sulfur, the conductive network of carbon fibers and hollow graphitized carbon spheres.
研究领域:
材料科学
·
电化学
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Journal of Materials Chemistry A
·
2023
·Vol. 12
·期 5
·2760-2770
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IF 11.9
Binchao Shi,Yue Wang,Ertai Liu,Shilin Mei,Chang-Jiang Yao
The fast capacity decay and limited cycling life are the two main issues that hinder the practical applications of lithium–sulfur batteries. They are mainly caused by the shuttle effect of polysulfide species and the growth of big lithium dendrites occurring separately on the cathode and anode sides. To simultaneously tackle these problems, we explore a multifunctional interlayer integrating the aligned nanochannel structure of an anodic aluminum oxide (AAO) membrane with porous 1T MoS2 nanotubes (namely MoS2@AAO). Benefiting from the high electronic conductivity, sulfiphilic and lithiophilic properties of 1T MoS2, and the positive surface plus low tortuosity of the straight channels of AAO, the designed interlayer not only guarantees rapid ion/electron transfer and efficacious suppression of the polysulfide shuttle, but also achieves uniform and stable lithium deposition during cycling. Consequently, the MoS2@AAO interlayer exhibits a high capacity retention of 99.6% at 0.2C after 500 cycles and 90.6% at 1.0C after 1000 cycles. The prototype cathode with a sulfur loading of 5 mg cm−2 was also investigated, which exhibited over 96% retention of the initial discharge capacity at 0.1C after 50 cycles. This work provides a new solution for simultaneously stabilizing both the lithium anode and sulfur cathode via an integrating approach.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2023
·
IF 7.2
Xin Xiao,Xiangmei Wang,Kui Li,Honglin Yan,Endian Fan,Miao Zhao,Hong Zhao,Dongping Sun,Li Chen
Transition metal sulfides (TMSs), especially iron-based metals (Fe, Co, Ni), were considered the most potential catalysts to replace noble metal-based materials for hydrogen evolution reaction (HER). This work selected metal ions as a variable to modulate the catalytic activity . Designing an electrode consisting of iron-based metal atoms sulfides sweeper-like hyperbranched clusters grown on nickel foam (NF) for HER. This particular structure consisted of 1D nanorods and adequate exposure of the lattice dislocation to exhibit enhanced electrocatalytic activity with low overpotential (135.9 mV) in alkaline conditions at 10 mA cm −2 . In addition, stability test results showed that the electrode exhibited good durability. The enhanced electrocatalytic activity of Ni–S could be owing to high electrical conductivity characteristic, the hierarchical structure constituted with NF and the large active surface area of the self-grown electrode further facilitating the production of H 2 . The Ni sites on the Ni 3 S 2 (110) crystal faces facilitated H adsorption, and all radical reactions under applied voltage proceed spontaneously. This work guides the selection and development of substrates for the design of synthetic transition metal catalysts , leading to cost-effective and efficient electrocatalytic hydrogen production .
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MACROMOLECULES
·
2023
·
IF 5.5
Xueting Lu,Yunli Liu,Dongxu Lu,Anqiu Xu,Yuexin Cao,Xiacong Zhang,Wen Li,Afang Zhang
Helical polymers with dynamic chirality are interesting not only for understanding the relationship between polymer structure and chiral conformation but also for developing responsive chiral polymeric materials. We report here the synthesis and characterization of a homologous series of dendronized poly(phenylacetylene)s (PPAs) via both macromonomer and grafting-to routes. These copolymers consist of achiral units carrying dendritic oligoethylene glycol (OEG) pendants and chiral units of dynamic imines formed from aldehydes and amino acids, which combine the constitutional dynamic chemistry (Schiff base) in the pendants with the conformational dynamic PPA backbones. Dendritic OEG pendants endow these copolymers with characteristic thermoresponsive behavior. The principles for modulating the helicity of these dendronized copolymers were examined, and factors including molecular structures (copolymer compositions and pendant linkage via ester or amide), solution pH, and thermally induced phase transitions have been investigated. These copolymers adopt tailored helicities in the presence of additional amino acids through multiple interaction balances between the copolymers and the amino acids. We believe that the methodology developed in this work will pave a convenient way to afford optically inactive copolymers or active polymers with featured dynamic helicity.
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高影响因子
POLYMER JOURNAL
·
2023
·Vol. 55
·期 12
·1295-1305
·
IF 2.8
Zhou Qian,Liu Bing,Jia Zhaolei,Gao Xuejiao,Ba Xinwu,Zhang Yuangong,Bai Libin
The aqueous solution of hyperbranched poly(bis-acrylamide)s (HPEAMs) prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization has a lower critical solution temperature (LCST), which can also respond to HCO 3 - . However, the phase change mechanism of HPEAMs has not yet been proven. In this paper, N -(2-propionamidoethyl)acrylamide was designed as a monomer and chain transfer agent (CTA), and the corresponding linear polymers, hyperbranched polymers and hyperbranched copolymers were further prepared. Fourier transform infrared spectroscopy, 1 H nuclear magnetic resonance, ultraviolet‒visible spectroscopy, dynamic light scattering and zeta potential were employed to characterize the structure and phase transition behavior. The results confirmed that the bis-acrylamide unit is hydrophilic and the CTA unit is hydrophobic. The hydrophilic-hydrophobic balance system constructed by the unit of bis-acrylamide and CTA endowed the hyperbranched polybisacrylamide with temperature-responsive behavior, and the carboxyl group in the CTA structural unit is the responsive group that makes it possible to tune the LCST in the presence of HCO 3 - .
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·
IF 3
Ao Nan Lai,Shu Chun Li,Pei Zhi Zheng,Shu Feng Zhou,Shi Jie Wu
A well-designed architecture is presented here to construct high-performance anion exchange membranes (AEMs). A series of quaternized fluorene-containing block poly(arylene ether sulfone ketone)s (QFPESK-m-n) is synthesized as the main chains, and grafted with comb-shaped C8 long alkyl chains for the AEMs. By varying the hydrophilic segment’ length, there has been a significant change in the microstructure as well as phase separation morphology of the membranes, as confirmed by atomic force microscopy. Hence the as-prepared AEMs with moderate ion exchange capacities (IECs) show enhanced hydroxide conductivities in the range of 28.8―94.7 mS⋅cm −1 from 30 to 80°C. Furthermore, based on the block backbones and hydrophobic comb-shaped alkyl chains, the AEMs show low-level swelling ratios of 4.3% to 9.2% at 30°C and from 6.2% to 13.2% at 80°C, and superior ratios of conductivity to swelling. In addition, the QFPESK-m-n AEMs also depict acceptable mechanical properties, good thermal stability and an optimizable alkaline stability.
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JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2023
·
IF 10.9
Haozhen Zhang,Jingjing Liu,Yong Zhang,Bei Cheng,Bicheng Zhu,Linxi Wang
Constructing step-scheme (S-scheme) heterojunctions has become a popular strategy for efficient photocatalytic H 2 O 2 generation. Herein, we in situ grew BiOBr nanosheets (NSs) on a Schiff-base covalent organic framework (COF) with large π-conjugated structures to prepare S-scheme BiOBr/COF photocatalysts for H 2 O 2 synthesis. The highest photocatalytic H 2 O 2 production performance of the composite sample constituting the S-scheme heterojunction is 3749 µmol g −1 h −1 , which was 1.85 and 27 times the rates of COF and BiOBr, respectively. The construction of S-scheme heterojunction contributed to efficient carrier transfer and separation in space and enhanced redox power. Moreover, the lying-down O 2 -adsorption configuration on the COF surface favors the concerted two-electron O 2 reduction process, which greatly reduced the reduction potential requirement for O 2 -to-H 2 O 2 conversion. The synergy between the S-scheme heterojunction and the unique O 2 –COF interaction boosted photocatalytic H 2 O 2 production activity.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Zheng-Xue Wu,Le-Qing Fan,Jiao-Juan Chen,Xu-Geng Deng,Tao Tang,Yun-Fang Huang,Ji-Huai Wu
Ternary metal sulfides employed in supercapacitors exhibit better electrochemical performances than their counterpart oxides due to their superior conductivity. However, the insertion/extraction of electrolyte ions can lead to a significant volume change in electrode materials , which can result in poor cycling stability. Herein, novel amorphous Co-Mo-S nanospheres were fabricated through a facile room-temperature vulcanization method. It involves the conversion of crystalline CoMoO 4 by reacting it with Na 2 S at room temperature . In addition to the conversion of the crystalline state into an amorphous structure with more grain boundaries, which is beneficial for the transport of electron/ion and can accommodate the volume change generated by the insertion/extraction of electrolyte ions, the production of more pores led to an increased specific surface area. The electrochemical results indicate that the as-prepared amorphous Co-Mo-S nanospheres had a specific capacitance of up to 2049.7F/g@1 A/g together with good rate capability. The amorphous Co-Mo-S nanospheres can be used as the cathode of supercapacitors and assembled with an activated carbon anode into an asymmetric supercapacitor possessing a satisfactory energy density of 47.6 Wh kg −1 @1012.9 W kg −1 . One of the prominent features exhibited by this asymmetric device is its remarkable cyclic stability, with a capacitance retention of 107% after 10,000 cycles.
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PubMed
高影响因子
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