ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Na Ye,Zhao Jiang,Tao Fang
Direct methanol fuel cells (DMFCs) have attracted extensive attention due to clean, efficient characteristics and portable applications. In this work, a series of Pd x Cu y /reduced graphene oxide (rGO) catalysts are assembled and the catalytic performances are investigated for methanol oxidation reaction (MOR) in alkaline media. The intrinsic surface electronic structures of the Pd x Cu y /rGO bimetallic catalysts are also studied to clarify the reaction mechanism. The results reveal that Pd 1.2 Cu 0.2 /rGO exhibits superior catalytic activity (1101.58 A g Pd −1 ), 4.2 and 5.2 times higher than those of the commercial PtRu/C and Pd/C catalysts. CO stripping suggests that the onset potential for CO oxidation on the Pd 1.2 Cu 0.2 /rGO catalyst is lower than those on the commercial PtRu/C and Pd/C catalysts, implying that the anti-CO poisoning ability is enhanced. Combined with the analysis of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Raman, the enhanced catalytic activity and anti-CO poisoning ability are attributed to the charge transfer and lattice compression between Pd and Cu, which modify the d-band center and weaken the adsorption of CO. Furthermore, a volcano plot is found between the MOR activity and d-band center, indicating that the excellent MOR activity is attributed to the optimal d-band center with the moderate adsorption strength of CO-like intermediates.
研究领域:
材料科学
·
电化学
·
催化反应
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DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2020
·
IF 3.594
Rui Zhao,Xingxing Wu,Yuxiang Gao,Yani Liu,Jiaojiao Gao,Yimai Chen,Zhou Zheng,Wei Gan,Qunhui Yuan
The first trial for electrochemical determination of Pb(II) with a bimetal organic framework derived composite, denoted as Co-N x -C@MWCNTs, is demonstrated in this work. The Co-N x -C@MWCNTs with three dimensionally braided structure was fabricated on the basis of zinc/cobalt co-centered bimetal zeolite imidazole framework (BMZIF-67) and interlaced with multi-walled carbon nanotubes (MWCNTs). Contributable to the presence of zinc/cobalt co-centers and the nitrogen-containing ligands, the homogenous dispersion of metallic cobalt and the formation of Co-N x moieties which were widely known as active sites in electrocatalysts were fulfilled. The integration of MWCNTs resulted in enhanced conductivity and extra porosity, which were also crucial for electrochemical sensing. Therefore, Co-N x -C@MWCNTs based electrochemical sensor exhibits good reliability for Pb(II) detection, with a low detection limit of 0.7 μg L −1 over a wide linear range of 2–60 μg L −1 . This design may shed lights on the fabrication of bimetal organic frameworks based electrochemical sensors in general.
研究领域:
材料科学
·
环境科学
·
分析化学
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高影响因子
Journal of Macromolecular Science Part B-Physics
·
2022
·
IF 1.366
Zemei Fang,Zhihua Zhou,Wei Wu,Wenjuan Liu,Hailin Xie,Hongbo Hu,Yan Gan,Jianjun Fang
A degradable blend scaffold composed of poly(D,L-lactide-co-glycolide-co-ε-caprolactone) (PLLGC) and ethanediamine modified poly(lactide-co-glycolide) (EMPLGA) was prepared by using a thermally induced phase separation technique. The morphologies of the PLLGC/EMPLGA blend scaffolds were characterized by using scanning electron microscopy (SEM). The in-vitro degradation behaviors and biocompatibility of the individual components and the blend were investigated by using rat L929 cells. The blend scaffolds showed a porous and well interconnected pore structure. The degradation rate sequence of the three scaffolds, the individual components and the blend, was EMPLGA > PLLGC/EMPLGA > PLLGC. The PLLGC/EMPLGA blend scaffold was non-cytotoxic and showed high cell proliferation.
研究领域:
生物材料
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组织工程
·
高分子科学
·
生物医学工程
·
体外降解
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高影响因子
MATERIALS CHARACTERIZATION
·
2022
·
IF 4.537
Shuang Liu,Limin Ma,Cheng Zhen,Yishu Wang,Dan Li,Fu Guo
In advanced microelectronic packaging technology, the interfacial brittleness of Cu/Sn solder joints puts forward higher requirements for high-performance diffusion barriers. Cobalt–Phosphorus (Co-P) alloy coating becomes ideal candidates for its good wettability and diffusion resistance. In this work, for Co-P with different crystallinity , the barrier properties of electrodeposited Co-P coatings as well as the mechanical properties of Co-Sn intermetallic compounds (IMCs) at the Co-P/Sn-Ag interface were investigated. According to the XRD results, the crystallinity of the Co-P coating was directly related to the phosphorus (P) content, and Co-P were classified into three types: crystalline state, mixed state and amorphous state. The morphology, composition, phase characterization, and mechanical properties of the Co-Sn IMCs at the interface were investigated by SEM , EPMA , TEM , and nanoindentation methods, respectively. After 180 °C aging test for 120 h, the thickness of CoSn 3 generated at the interface of crystalline Co-4.2 at.% P/Sn-Ag was the smallest among a total of 18 Co-P coatings, where P content ranged from 0.9 at.% to 20.8 at.%, showing the best barrier properties. The hardness of (Co,Cu)Sn 3 at the amorphous Co-P/Sn-Ag interface was the lowest (3.2 GPa), which was only 47% of that of Ni 3 Sn 4 , exhibiting the lowest brittleness tendency. The mixed crystalline-amorphous Co-P could greatly improve the diffusion barrier properties while sacrificing a small degree of brittleness comparing to the amorphous coatings, and had the potential to become a general-purpose alloy coating. This work could provide a scientific basis for the selection of Co-P barrier layers with excellent barrier properties and mechanical properties leading to different application scenario in electronic packaging.
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DOI
高影响因子
MACROMOLECULAR BIOSCIENCE
·
2015
·Vol. 15
·期 6
·829-838
·
IF 3.851
Haiyang Yu,Zhaohui Tang,Dawei Zhang,Wantong Song,Taicheng Duan,Jingkai Gu,Xuesi Chen
A novel random copolypeptide of ornithine, arginine, glycine, and aspartic acid [Poly(ornithine-co-arginine-co-glycine-co-aspartic acid), Poly(O,R,G,D)] has been prepared through ring-opening polymerization of N -δ-carbobenzoxy-l-ornithine N -carboxyanhydride [Orn(Cbz)-NCA)], l-glycine N -carboxyanhydride (Gly-NCA) and β-benzyl l-aspartate N -carboxyanhydride [Asp(Bn)-NCA], following by subsequent deprotection and guanidization. The structure of Poly(O,R,G,D) was confirmed by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Low cytotoxicity of Poly(O,R,G,D) was confirmed from MTT assay. The Poly(O,R,G,D) contain some internal sequences of RXXR ( X = O, R, G, or D) that could be proteolytically cleaved to expose the cryptic CendR element and bind to Neuropilin-1. This would lead to vascular and tissue permeabilization. Therefore trypsin-cleaved Poly(O,R,G,D) increase the vascular leakage of Evans blue from dermal microvessels at the injection site in vivo skin permeability assay. The intratumoral injection of the Poly(O,R,G,D) significantly enhanced the concentration of cisplatin-loaded nanoparticles in MCF-7 solid tumors. These results show that Poly(O,R,G,D) could increase the vascular leakage and tissue penetration of nanoparticles in a solid tumor and can be used as a potential polymeric tumor-penetrating agent.
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DOI
PubMed
高影响因子
MACROMOLECULAR RESEARCH
·
2013
·Vol. 21
·期 12
·1338-1348
·
IF 1.639
Xu Yiting,Xie Jianjie,Chen Lingnan,Yuan Conghui,Pan Yinyin,Cheng Ling,Luo Weiang,Zeng Birong,Dai Lizong
A novel organic/inorganic hybrid amphiphilic random copolymer poly(methacrylate isobutyl POSS- co -N-isopropylacrylamide- co -oligo(ethylene glycol) methyl ether methacrylate- co -2-vinylpyridine), poly(MAPOSS- co -NIPAM- co -OEGMA- co -2VP), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The self-assembly behavior of random copolymers in aqueous solution was investigated by dynamic light scattering (DLS) as well as transmission electron microscopy (TEM). The results indicate the novel random copolymer in water could self-assemble into spherical aggregates and the self-aggregate size displays a remarkable dependence on pH. The stimuli-responsive characteristics of these assembles were tested by means of UV-vis spectra, DLS and TEM. There is a critic Zn 2+ concentration over which the aggregates can be coordinated into well-define spherical aggregate clusters. The critic Zn 2+ concentration can be tuned finely through adjusting solution concentration or 2VP amount. Results from UV-vis and DLS reveal that the copolymer solutions exhibit a sharp and intensive lower critical solution temperature (LCST). Some factors such as the solution concentration, molecular weight, pH and copolymer generation, which could affect the cloud point, were studied systematically. The essentially predetermined LCST can be achieved by altering the content of 2VP or pH. In addition, these novel hybrid aggregates can undergo an association/disassociation cycle with the heating and cooling of solution and the degree of reversibility shows a strong concentration dependence. As a novel organic-inorganic hybrid material which can respond to multiple external stimuli including temperature, pH, metal ions with sharp stimuli-responsive behaviors, it is potentially used for biomedicine, catalysis, diagnostics, bioseparations, biosensors and for fundamental investigation.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Yanjia Zhou,Guihong Lan,Yongqiang Liu,Songsong Xue,Bo Xu,Haiyan Qiu,Keyu Pu
To obtain a demulsification material with convenient recovery, high oil-water separation capacity, and excellent reusability, Fe 3 O 4 @SiO 2 core-shell particles and hydrophilic DMC were introduced into the acrylic ester-based polymer system to prepare a magnetic amphiphilic composite demulsifier, Fe 3 O 4 @SiO 2 /poly(SMA-co-BA-co-BZMA-co-DMC) (Fe 3 O 4 @SiO 2 /PAMCs-P). The molecular structure of Fe 3 O 4 @SiO 2 /PAMCs-P was characterized using FT-IR and XPS, while the morphology was observed using SEM. Additionally, the effects of TEOS, Fe 3 O 4 @SiO 2 core-shell particles, and DMC dosage on the demulsification performance of the composites were discussed in detail. Fe 3 O 4 @SiO 2 /PAMCs-P exhibited excellent demulsification, oil-water separation, and reusability properties for CTAB-toluene emulsions. Under magnetic field conditions, Fe 3 O 4 @SiO 2 /PAMCs-P achieved saturated separation within 2 h with a separation efficiency of 97.9%. After five consecutive separations, the separation efficiency decreased to 39.1%, but it could be restored to 91.5% of the initial separation efficiency after desorption. These results indicate that Fe 3 O 4 @SiO 2 /PAMCs-P has valuable application potential in emulsified wastewater treatment.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Lei Liu,Ning Liu,Chengna Dai,Ruinian Xu,Gangqiang Yu,Ning Wang,Biaohua Chen
Realizing MoS2 basal plane activation is highly desirable and challenging in the field of hydrodesulfurization (HDS). Herein, we have developed a new strategy of dual Co single atom doping (SAD) combined with CO in situ regulation, which can successfully activate the basal plane of Co3.6%–MoS2-0.3 generating high ratios of thermostable 1T-plane (∼70%) and large S vacancies. For the first time, a synergistic effect has been unraveled where the lattice substituted neighboring dual SA Co can efficiently activate in-plane S through extensively reducing its band gap (2.21 → 0.14 eV), which tremendously favors S subtraction and 2H → 1T phase transition assisted by CO. Boosted thiophene HDS activity can be eventually achieved with the reaction rate constant (k) being 8.3 times higher than that of commercial cCo3.6%–MoS2 (0.04 → 0.33 h–1). Generally, the present work paves a new way for next-generation HDS catalyst design with activated basal plane.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Wenhui Li,Xiaowa Nie,Hong Yang,Xiang Wang,Felipe Polo-Garzon,Zili Wu,Jie Zhu,Jianyang Wang,Yi Liu,Chuan Shi,Chunshan Song,Xinwen Guo
Efficient conversion of CO 2 is of great significance for sustainable supply of chemicals and fuels. While Co-based catalysts are known to be effective for CO hydrogenation in Fischer-Tropsch synthesis, they work very differently in CO 2 hydrogenation. This study reveals a crystallographic dependence of reaction pathways for CO 2 hydrogenation on Co catalyst showing a new type of structure sensitivity and structure-activity-selectivity relationship for CO 2 conversion to chemicals and fuels. The experimental work on CO 2 conversion including steady-state isotopic transient kinetic analysis (SSITKA) using 13 C-labeled CO 2 shows a preferential CH 4 formation over HCP-Co but dominant CO formation over FCC-Co. The density functional theory calculations indicate that CO 2 does dissociate directly into chemisorbed CO* and O* on both HCP-Co and FCC-Co, but the CO* intermediates on HCP-Co prefer to be hydrogenated to form CH 4 whereas the CO* on FCC-Co preferentially desorb to form CO. The significantly altered adsorption strength of CO* due to the presence of chemisorbed O* and CO 2 * species on the catalyst surface is responsible for the mechanistic disconnection in product selectivity between the CO 2 and CO hydrogenation over Co catalysts. This study also shows that the addition of K to Co diminishes the direct impact of Co crystal structure, but improves the selectivity to C 2 + hydrocarbons along with higher CO 2 conversion. This seems to result from another pathway originating from HCOO* intermediate from bonding interaction of surface Co atoms with carbon in CO 2 , leading to the formation of CH x * whose coupling subsequently give rises to C 2 + products. The present study sheds new light into the crystallographic structural sensitivity of CO 2 hydrogenation towards the rational design of more selective catalysts for CO 2 conversion.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Yu Wang,Honghao Yu,Liangkui Zhu,Zhiqiang Shi,Runwei Wang,Zongtao Zhang,Shilun Qiu
Carbon-metal composites are promising multifunctional electrocatalysts , but it is still challenging to prepare carbon-metal composites with tunable structure and strong metal-carbon interactions. Here, we present a unique gas-foaming assembly strategy to prepare cytosine-Co chelate derived Co and N codoped carbon nanotube (Co-NCNT). The structure for Co-NCNTs could be easily controlled by regulating cytosine-Co coordination or the carbonization temperature. The optimal Co-NCNT possesses homogeneous distributed NCNTs (10 nm), CoO x (5 nm) and CoN x moieties to synergistically boost electrochemical processes, and offer mesoporous nanosheet architecture to guarantee fast mass migrate and electron transfer . As a result, Co-NCNT shows remarkable ORR performance (onset potential of 0.93 V in 0.1 M KOH electrolyte) along with significant OER and HER activity. More important, it was found that CoN x moieties are responsible for the remarkable electrocatalytic activity in Co-NCNTs, because CoN x could alter active center, enhance metal-carbon synergy, decrease interfacial resistance and reinforce the strength of composites. Therefore, this paper not just demonstrates an advanced multi-functional electrocatalyst, but could also give deep understanding on the designing of multifunctional electrocatalysts.
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DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 89
·56183-56193
·
IF 3.108
Yong Zhang,Bin Yang,Kuiling Li,Deyin Hou,Changwei Zhao,Jun Wang
A novel terpolymer (abbreviated as THV), which is a copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride, that possesses advantages of excellent hydrophobicity, mechanical properties, and chemical resistance is an ideal material for membrane distillation. In this study, THV hydrophobic membranes were fabricated by the electrospinning method. Morphology and properties (pore size distribution, liquid entry pressure, porosity, and contact angle) of the THV electrospun membranes with various fabrication conditions (solvent composition, THV concentration, and applied voltage) were systematically studied. Under the optimized condition, the membrane exhibited a good structure, wetting resistance, and surface hydrophobicity. The mean pore size, liquid entry pressure of water (LEPw), and contact angle were 0.79 μm, 118.0 kPa, and 130.7°, respectively. Owing to the advantages of the raw material and fabrication method, the membrane showed excellent mechanical properties and desalination performance. The tensile strength was 5.41 MPa, and the elongation at break was 247.9%, which were 2.47 and 5.61 times higher than those of the poly(vinylidene fluoride) (PVDF) membrane, respectively. Additionally, the membrane distillation flux was 4.42 kg m−2 h−1, which was 1.93 times higher than that of the PVDF counterpart obtained under the same test condition via sweeping gas membrane distillation, and the salt rejection rate was higher than 99.8%.
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高影响因子
International Journal of Minerals Metallurgy and Materials
·
2024
·Vol. 32
·期 1
·169-181
·
IF 5.6
Li Haixu,He Haobo,Jiang Tiannan,Du Yunfei,Wu Zhichen,Xu Liang,Wang Xinjie,Liu Xiaoguang,Yu Wanhua,Xue Wendong
S and Co co-doped carbon catalysts were prepared via pyrolysis of MOF-71 and thiourea mixtures at 800°C at a mass ratio of MOF-71 to thiourea of 1:0.1 to effectively activate peroxymonosulfate (PMS) for methylene blue (MB) degradation. The effects of two different mixing routes were identified on the MB degradation performance. Particularly, the catalyst obtained by the alcohol solvent evaporation (MOF-AEP) mixing route could degrade 95.60% MB (50 mg/L) within 4 min (degradation rate: K = 0.78 min −1 ), which was faster than that derived from the direct grinding method (MOF-DGP, 80.97%, K = 0.39 min −1 ). X-ray photoelectron spectroscopy revealed that the Co–S content of MOF-AEP (43.39at%) was less than that of MOF-DGP (54.73at%), and the proportion of C–S–C in MOF-AEP (13.56at%) was higher than that of MOF-DGP (10.67at%). Density functional theory calculations revealed that the adsorption energy of Co for PMS was −2.94 eV when sulfur was doped as C–S–C on the carbon skeleton, which was higher than that when sulfur was doped next to cobalt in the form of Co–S bond (−2.86 eV). Thus, the C–S–C sites might provide more contributions to activate PMS compared with Co–S. Furthermore, the degradation parameters, including pH and MOF-AEP dosage, were investigated. Finally, radical quenching experiments and electron paramagnetic resonance (EPR) measurements revealed that 1 O 2 might be the primary catalytic species, whereas ·O 2− might be the secondary one in degrading MB.
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危险品化学品经营许可证（带存储）