CERAMICS INTERNATIONAL
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2024
·
IF 5.1
Shaodong Xu,Yuan Yu,Dongfeng Sun,Yanning Qu,Linyin Huang,Yuhao Fan,Nandong Li,Pengpeng Qiang,Qingmei Su,Xiaodong Hao,Gaohui Du,Kai wang,Bingshe Xu
High reflection loss and wide absorption bandwidth materials are in great demand to prevent electromagnetic pollution and military applications. The composites prepared by combining different components with good dielectric and magnetic losses are expected to achieve ideal absorbing performance. In this study, a composite of cobalt nanoparticles enveloped in nitrogen-doped bamboo-like carbon nanotubes (Co@N-CNTs) was prepared by one-step annealing the mixture of melamine and cobalt nitrate at 800 °C in a mixed atmosphere of hydrogen and argon. Co nanoparticles derived from the reaction between H 2 and cobalt nitrate during the sintering process were used as catalysts to prompt the carbonization of melamine and the formation of the bamboo-shaped N-doped carbon nanotubes, thus forming the composite structure of bamboo-shaped N-doped carbon nanotubes encapsulated with Co nanoparticles. This Co@N-CNTs composite not only had an excellent dielectric loss and magnetic loss but also greatly improved its impedance matching, thus having good electromagnetic wave absorption performance. The coating made from the Co@N-CNTs composite had a maximum reflection loss (RL) of −35.89 dB at only 1.8 mm thickness at 14.1 GHz and possessed an effective absorption bandwidth of up to 4.91 GHz (12.35–17.26 GHz), suggesting it a high-performance and wide-absorption bandwidth composite material.
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CHEMICAL PHYSICS LETTERS
·
2024
·
IF 2.8
Xueying Wang,Qian Ma,Yi Wang,Lingyu Li,Dongheng Zhao,Huayushuo Zhang,Bolong Li
Bimetallic MOFs-derived hierarchical WO 3 /ZnWO 4 /CoWO 4 heterostructures were prepared by electrospinning for achieving superior n-butanol-sensing property at low operating temperatures. Porous chain-like structures can gradually transformed into porous mulberry-like structures composed of various accumulated particles as increasing the additive amount of Zn/Co-ZIFs. High selectivity and stability of WO 3 -based composites to 100 ppm n-butanol can be observed at 25 °C, including the large sensitivity of 32 and the fast response/recovery times of 115/179 s. The enhanced gas-sensing performance is primarily ascribed to the increased specific surface area, plentiful polyoxometalate, and effective heterojunctions, obviously promoting surface/interface absorption behavior and electron transport process.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
·
IF 8.1
Kai Liu,Zizai Ma,Zihao Wan,Xiaoguang Wang
In this article, the hydrogen evolution performance in 0.5 M H 2 SO 4 and 1.0 M KOH is improved by introducing N atoms into Ni 2 P/Co 2 P through high-temperature doping (N–Ni 2 P/Co 2 P). N–Ni 2 P/Co 2 P has a lower overpotential than Ni 2 P/Co 2 P, which can achieve cathodic current densities of 10 mA cm −2 , 100 mA cm −2 at overpotentials of 48 mV, 228 mV in 1.0 M KOH and 63 mV, 211 mV in 0.5 M H 2 SO 4 . Density functional theory (DFT) results found that the introduction of N atoms changed the electronic structure of the catalyst. Due to the forward shift of d-band center, the binding force between the catalyst and H∗ is enhanced, providing favorable conditions for hydrogen evolution. Furthermore, the results of scaled-up tests show that 5 cm × 5 cm N–Ni 2 P/Co 2 P electrodes still exhibit superior performance, revealing a prospect of industrialization.
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Energy Technology
·
2024
·Vol. 12
·期 7
·2400062
·
IF 3.6
Demin Jiang,Huina Chen,Liangjuan Zhu,Wei Wang,Yuqiao Wang
Biofouling of air cathode surface decreases the electricity generation performance of membrane-free microbial fuel cells (MFCs). Ag@Co/Zn N-doped carbon (Ag@Co/Zn-NC) is designed as an antibacterial oxygen reduction reaction (ORR) catalyst to inhibit biofouling on the cathode surface. The Co/Zn-NC active component promotes ORR catalytic activity through the advantages of well-distributed Co nanoparticles and numerous active sites. Superficial Ag nanoparticles act as antibacterial active species to inhibit bacterial proliferation and suppress biofilm growth. Ag@Co/Zn-NC catalyst prevents bacterial adhesion and biofilm formation, effectively preventing excessive biofouling on the cathode surface. The antibacterial catalyst maintains a high catalytic activity and good ion diffusion properties without the adverse effects of biofouling, resulting in enhanced ORR durability of the air cathode. The assembled MFCs achieve high electricity generation during long-term cyclic operation. The maximum power density retention percentage (82.6%) is higher than that of Co/Zn-NC MFC (65.3%) and Pt/C MFC (52.4%) after continuous operation for 1200 h. Excellent operational durability is revealed for the air-cathode MFCs assembled with the antibacterial ORR catalyst during the cyclic process. The novelty of this study is that the design of antibacterial catalysts inhibits the excessive growth of the cathode biofilm to improve the cyclic electricity generation performance of MFCs.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Xinpeng Guo,Jian Yin,Haishuai Cui,Jiating Gong,Siqi Cheng,Yunlong Li,Xinglu Deng,Feiying Tang,Shaofeng Xiong,Pingle Liu
The N-formylation reaction of amines by CO 2 hydrogenation is a promising method for converting CO 2 into chemical products with industrial application value. However, most of the currently developed catalysts are metal-homogeneous catalysts, which contain metal pollution and are not easy to recycle. Thus, we modified carbon nanotubes with N-containing amino compounds and prepared a polyethylenimine (PEI) grafted carbon nanotubes metal-free catalyst, which was applied to the N-formylation reaction of CO 2 and aniline. By adjusting the grafting concentration and the type of amino compound, the acid-base properties and surface defects of the catalyst were regulated. The CNT-0.5PEI catalyst had the optimal catalytic activity after 12 h of reaction at 80 °C, with a conversion rate of 95.41 % for aniline and a selectivity of 94.04 % for the target product N-formylaniline. It reveals that its catalytic performance can be comparable to the reported homogeneous catalysts. Our research found that increasing the surface defects and basic sites of carbon nanotubes was conducive to the enrichment and activation of CO 2 , thereby enhancing the catalytic activity. The experimental and calculation results indicate that the reaction has relatively low activation energy under the catalysis of CNT-0.5PEI, and the catalyst has the strongest adsorption capacity for CO 2 and aniline reactants. In addition, the CNT-0.5PEI displays a wide range of substrate applicability and excellent cyclic stability. Therefore, cheap and environmentally friendly metal-free modified carbon nanotube catalyst is an ideal substitute for scarce and polluting metal homogeneous materials. It has important reference significance for the efficient conversion and utilization of CO 2 catalyzed by metal-free catalyst.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2012
·Vol. 88
·期 3
·437-443
·
IF 2.168
Min Jia,Hongmin Cui,Weiqun Jin,Lili Zhu,Yu Liu,Ji Chen
BACKGROUND: Rhenium is a rare and valuable metal coexisting with molybdenum in molybdenite and sulfide copper ores and is hard to separate. Methods such as solvent extraction, ion exchange, adsorption, precipitation, etc. have been used to separate and purify Re(VII), and resin ion exchange has been widely investigated and used owing to its convenient operation and relatively low-cost. The main challenge comes from the preparation of resins having high performance and stability. In an earlier study, an N-methylimidazolium functionalized strong basic anion exchange resin was successfully synthesized and used for Cr(IV) extraction. This paper, reports on further synthesis and application of this resin for adsorption and separation of Re(VII) and Mo(VI), especially from copper arsenic filter cake. RESULTS: At pH 6.25, Re(VII) and Mo(VI) can be effectively separated with the N-methylimidazolium functionalized strong basic anion exchange resin, giving a Re(VII) recovery of up to 93.3%, but only 5.1% for Mo(VI). When using the copper arsenic filter cake sample 89.1% Re(VII) recovery was achieved. CONCLUSION: The N-methylimidazolium functionalized strong basic anion exchange resin exhibited high selectivity and recovery for Re(VII) in a mixed system. © 2012 Society of Chemical Industry
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JOURNAL OF HAZARDOUS MATERIALS
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2012
·
IF 4.173
Chao Zhou,Naiyun Gao,Yang Deng,Wenhai Chu,Wenlei Rong,Shengdong Zhou
Disinfection by-products (DBPs) are a great challenge to our drinking water security. Particularly, nitrosamines (NAms), as emerging DBPs, are potently carcinogenic, mutagenic, and teratogenic, and have increasingly attained public attention. This study was to evaluate the performance of the NAms degradation by the ultraviolet (UV) irradiation (253.7 nm) in the presence of hydrogen peroxide (H 2 O 2 ). In the UV/H 2 O 2 system, hydroxyl radicals (OH ), a type of nonselective and powerful oxidant, was produced to attack the molecules of NAms. Factors affecting the treatment efficiency, including the H 2 O 2 dosage, initial NAms concentration, UV irradiation intensity, initial solution pH, and inorganic anions present in water, were evaluated. All the NAms degradation exhibited a pseudo-first-order kinetics pattern. Within 60 min, 0.1 mg/L of any NAms could be almost decomposed except NDPhA that required 120 min for complete removal, at 25 μmol/L H 2 O 2 and at initial pH 7. Results demonstrate that the UV/H 2 O 2 treatment is a viable option to control NAms in water.
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ANALYST
·
2024
·
IF 3.6
Longmei Yao,Xue Mei,Jiajia Zhi,Wenchang Wang,Qingyi Li,Ding Jiang,Xiaohui Chen,Zhidong Chen
In this study, a novel electrochemiluminescent (ECL) sensor for highly sensitive detection of trilobatin (Tri) was developed based on silver metal–organic frameworks (AgMOFs) and nitrogen-doped carbon quantum dots (N-CDs). N-CDs exhibited high ECL intensity but poor ECL stability, while AgMOFs had a large specific surface area, high porosity, and good adsorption properties. Compositing both of them not only improved the ECL stability of N-CDs, but also enhanced the ECL strength of materials, so AgMOF@N-CD composites were used as the luminophore of the sensor. Under the optimized conditions, the ECL sensor showed a linear range of 1.0 × 10−7 M to 1.0 × 10−3 M for the detection of Tri, and the detection limit was as low as 5.99 × 10−8 M (S/N = 3). In addition, the sensor had excellent reproducibility, stability, and anti-interference ability. It could be utilized for the detection of Tri in real samples with recoveries of 95.78–102.26%, indicating that the constructed ECL sensor for detecting Tri possessed better application prospects.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2011
·Vol. 124
·期 6
·4678-4685
·
IF 1.24
Ying Chen,Yongbing Chen,Jingya Nan,Chunpeng Wang,Fuxiang Chu
A convenient approach has been developed for the preparation of microsize hydrogels composed of crosslinked poly(acrylic acid) (PAA) and poly( N -isopropylacrylamide) (PNIPAm). First, semi-interpenetration polymer networks of hydropropylcellulose (HPC) and PNIPAm- co -PAA copolymer are formed through the copolymerization and crosslinking of monomer acrylic acid and N -isopropylacrylamide in HPC aqueous solution. After the selective removal of HPC from networks due to ionization of PAA units and disruption of hydrogen bonding with increasing pH, PNIPAm- co -PAA microgels are obtained, whose volume is confirmed to be responsive to both temperature and pH. Doxorubicin hydrochloride (Dox) can be encapsulated in PNIPAm- co -PAA microgels with high drug loading driven by the electrostatic interaction, and a sustained-release characteristic of Dox from the microgels is observed under physiological pH value and temperature. In vitro cell experiments, the drug-loaded microgels can be taken up by LoVo cells and release their payload in cell cytoplasm without loss of drug efficacy. This indicates that PNIPAm- co -PAA microgels might be a potential drug delivery carriers especially for water-soluble or polypeptide drugs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
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SYNLETT
·
2011
·Vol. 2012
·期 01
·145-149
·
IF 2.447
Wenpeng Mai,Jinwei Yuan,Zhicheng Li,Gangchun Sun,Lingbo Qu
All articles of this category A novel direct arylation of pyridine N -oxideswith arylboronic acids through C-H functionalization hasbeen developed. This new reaction is performed at room temperatureusing catalytic silver(I) nitrate in the presence of potassium persulfateand give 2-pyridyl arylation derivatives of pyridine N -oxides.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xu-Wei Luo,Ming-Ran Zhou,Mao-Jin Ran,Dao-Xiang Xun,Jia-Le He,Zhi-Yi Hu,Hemdan S.H. Mohamed,Jing Liu,Li-Hua Chen,Yu Li,Bao-Lian Su
Lithium-selenium (Li-Se) batteries have attracted increasing attention because of excellent carbonate electrolyte compatibility, comparable theoretical volumetric specific capacity and high electrical conductivity. However, there are still unavoidable issues such as large volume expansion, rapid capacity decay and slow electrochemical reaction kinetics for practical applications. In this work, we report 2D ZIF-8 derived N-doped porous carbon nanosheets (NPC-NS) as Se host for high-performance Li-Se batteries. The unique 2D structure of Se@NPC-NS facilitates Li + diffusion and charge transfer, thus the Se@NPC-NS cathode exhibits fast electrochemical reaction kinetics. In addition, the N doping enhances electronic conductivity and porous structure mitigates the volume expansion. As a result, the Se@NPC-NS cathode delivers a high reversible capacity of 585 mAh/g with a capacity retention of 99.1 % at 0.5C (1C = 675 mA g −1 ) after 225 cycles. Especially after 500 cycles at a high current density of 10C, the Se@NPC-NS cathode still displays a reversible specific capacity of 307 mAh/g with only 0.03 % capacity decay per cycle. This work would shed some light on the 2D carbon host as Se-based cathode for high-rate and long-life performance Li-Se batteries.
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Science Bulletin
·
2025
·
IF 21.1
Qingyu Wang,Yangyang Wan,Qichen Liu,Yida Zhang,Zhentao Ma,Zirui Xu,Pengting Sun,Gongming Wang,Hai-Long Jiang,Wenping Sun,Xusheng Zheng
Photocatalytic urea production from nitrogen (N 2 ) and carbon dioxide (CO 2 ) is a sustainable and eco-friendly alternative to the Bosch-Meiser route. However, it remains a significant challenge in developing highly efficient photocatalysts for enhancing C-N coupling to high-yield urea synthesis. Herein, we propose a multi-site photocatalyst concept to address the concern of low yield by simultaneously improving photogenerated carrier separation and reactant activation. As a proof of concept, a well-defined multi-site photocatalyst, Ru nanoparticles and Cu single atoms decorated CeO 2 nanorods (Ru-Cu/CeO 2 ), is developed for efficient urea production. The incorporation of Ru and Cu sites is crucial not only to generate high-density photogenerated electrons, but also to facilitate N 2 and CO 2 adsorption and conversion. The in situ formed local nitrogen-rich area at Ru sites increases the encounter possibility with the carbon-containing species generated from Cu sites, substantially promoting C-N coupling. The Ru-Cu/CeO 2 photocatalyst exhibits an impressive urea yield rate of 16.7 μmol g −1 h −1 , which ranks among the best performance reported to date. This work emphasizes the importance of multi-site catalyst design concept in guaranteeing rapid C-N coupling in photocatalytic urea synthesis and beyond.
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