Catalysts
·
2019
·Vol. 9
·期 11
·911
·
IF 3.444
Tianming Liu,Guobao Yuan,Guocheng Lv,Yuxin Li,Libing Liao,Siyao Qiu,Chenghua Sun
Microwave-induced catalytic degradation (MICD) has been considered as one of the most prospective approaches to remove organic contaminants from water. High-performance catalysts, ideally offering efficient degradation ability, are essential to this process. This work reports the fabrication of manganese oxide on carbon nanotubes (MnO/CNTs) as an efficient catalyst under microwave irradiation (MI) to remove tetracycline (TC) from aqueous solution. The hybrid MnO/CNTs structure shows excellent performance in TC degradation. Combining experimental characterization and theoretical calculations, synergistic mechanisms are revealed: (i) Strong MnO/CNTs interaction stabilizes Mn(II) through interfacial bonding; (ii) high-spin states associated with low coordinated Mn(II) play a major role in MICD; and (iii) superoxide radicals (•O2−) and hydroxyl radicals (•OH) induced by microwave input are identified as the major active species.Keywords:microwave-induced;manganese oxide;catalysts;tetracycline;degradation
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2018
·Vol. 33
·期 11
·1910-1916
·
IF 3.608
Airui Zhang,Hai Wang,Pengfei Zha,Meiling Wang,Haifeng Wang,Bingqi Fan,Danhua Ren,Yanxiang Han,Sitian Gao
An analytical method of microwave induced combustion (MIC) combined with ICP-OES and TXRF is proposed to determine elemental impurities in graphene. Optimized MIC conditions (e.g. sample mass up to 30 mg, microwave irradiation 900 W for 10 min, and oxygen pressure 2 MPa) can achieve the rapid and complete digestion of graphene. Analytical results show that this method can accurately determine elemental impurities such as S, Fe, Cr, Mn and Ni in graphene, and that ICP-OES and TXRF data are comparable. The validity of this method is also verified using three different CRMs for cellulose nanocrystal powder and single-wall carbon nanotubes. The limits of detection (LODs) using MIC combined with ICP-OES are 5.4, 10.6, 7.3, 0.7 and 2.7 μg kg−1 for Fe, S, Cr, Mn and Ni, respectively. The LODs using MIC coupled with TXRF are 30.2, 215, 21.3, 9.5 and 15.8 μg kg−1 for Fe, S, Cr, Mn and Ni, respectively. The experimental results are also compared with those from three other pretreatment methods including dry ashing coupled with acid digestion (DA-AD), microwave-assisted digestion (MWAD) and DA-MWAD, which shows that MIC is superior to the other procedures due to the incomplete digestion and/or escape of volatile S of the latter. The MIC digestion combined with ICP-OES or TXRF could be one of the most promising procedures for the accurate determination of some elemental impurities in carbon nanomaterials with stable structures like graphene.
研究领域:
分析化学
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材料科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 23
·64352-64362
·
IF 5.8
Qian Cheng,Ma Jie,Wu Qiong
As a typical carbamate pesticide, methomyl was once widely used in agriculture for its excellent broad-spectrum insecticidal effect. However, due to its high toxicity, long half-life, and difficult degradation properties, it poses a serious challenge to water environment pollution. In this study, an electrode-free discharge microwave-induced plasma technology was used to rapidly and efficiently degrade methomyl in aqueous solution. In this experiment, the statistical design of experiments (DOE) was adopted to optimize the plasma degradation parameters. Under the optimized parameters ( P = 140 W, D = 0 mm, R = 0.5 L/min), 78.4% removal of 50 mg/L of methomyl was achieved after 8 min. The optical emission spectrometry and free radical detection experiments showed that the active substances generated by the collision reaction between plasma and water molecules occurring at the gas–liquid interface were the key factors to exert the degradation effect. The degradation rate of methomyl decreased by 73.2% after the addition of tert-butanol (OH burster), while it decreased by only about 12.0% after the addition of peroxidase. These implied that ∙OH was largely responsible for methomyl degradation. In addition, based on the detected intermediates, possible degradation mechanisms and pathways were analyzed.
研究领域:
环境科学
·
农药污染治理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Gaobang Chen,Yong Fan,Tianhui Yu,Muhammad Shoaib,Azim Khan,Yifan Liu,Xian Jian
The practical application of high-rate lithium/fluorinated carbon (Li/CF x ) primary batteries faces challenge of relatively slow electrode reaction kinetics limited by inert C-F bond and strong polarity. Herein, an effective microwave-induction strategy was developed to regulate C-F bond for 80C high-rate Li/CF x battery with suppressed polarization. The as-mentioned microwave method was carried out in the alcohol-based solvent for uniformly modify CF x , including precise defluorination, C-F bond regulation, surface functional groups and carbon quantum dots. Precise defluorination contains the conversion of C-F bond to semi-ionic C-F bond while preserving C-F 2 and C-F 3 . During the process of C-F bond regulation, hydroxyl groups is grafted onto the surface of CF x to increase the wettability and electronegativity of the electrode. Compared with raw CF x , the Li/CF x batteries using microwave-modified CF x achieved high discharge rate of 80C possessing a high power density of 134.091 kW/kg. In addition, the optimal Li/CF x battery possesses a large specific capacity increase ratio of 142.6 % at 50C. This microwave-induction approach for modifying CF x in ethanol-based solvent provides a facile and effective pathway to design high-rate Li/CF x battery.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Peiyan Liu,Meiri Wang,Jing Li,Hongtao Cui,Tao Zeng,Shubin Yang,Huan Wang,Yuanyuan Liu
Rechargeable aqueous Zn//MnO 2 batteries are the promising alternatives to lithium-ion batteries owing to their high safety, high energy density, low cost, and environmental friendliness. However, the unstable MnO 2 cathode causes poor practical energy density and serious capacity fading. To overcome this issue, herein, a unique 2D nanosheets self-supported 3D δ -MnO 2 microflower hierarchical architecture is rationally designed and synthesized by taking advantage of its microwave-absorbing characteristics. The 2D nanosheets with high surface area could expose numerous active sites for ions/electrons transfer. Also, the 3D assembled structure acting as building blocks would ensure structural stability for long-life cycles. Benefiting from these synergistic merits, the δ -MnO 2 microflowers deliver a high capacity of 287.6 mA h g −1 at 0.5 C, an excellent rate capability of 202.7 mA h g −1 at 5 C, and a superior cycling retention of 76.5% over 1000 cycles at 10 C. Furthermore, a storage mechanism of H + /Zn 2+ co-insertion accompanied by the deposition of zinc sulfate hydroxide hydrate is clarified by the aid of ex-situ XRD and SEM technologies. This work provides a new pathway for developing high capacity and long lifespan ZIBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Frontiers in Energy Research
·
2023
·
IF 3.4
Jia Pingshan,Sun Jing,Wang Wenlong,Song Zhanlong,Zhao Xiqiang,Mao Yanpeng
Microwave-induced metal arc discharge provides an intriguing solution for the synthesis of carbon-coated metal nanoparticles (M@CNPs) due to its fast formation and improved quality of products, however, the underpinning reaction mechanism is not comprehensively revealed. In this work, the effect of arc discharge intensity on the product morphology is firstly investigated by adjusting microwave power. And then, the effects of the organic groups (i.e. cyclopentadienyl v. s Acetylacetonate groups) and metal catalysis on the product morphology are also investigated by selecting ferrocene, iron acetylacetonate, nickelocene, and nickel acetylacetonate as precursors. Specifically, moderate microwave power can not only destroy the precursor to form carbon nanosheets by inducing intense discharge heat release but also provide sufficient intermittency to allow the carbon nanosheets to deposit on the surface of the metal core, which is an important precondition in fabricating M@CNPs. The structure of organic groups in the precursor also plays a predominant role in adjusting product morphology. Cyclopentadienyl groups tend to encapsulate the metal core to form graphitized carbon shells as the coordination bond between cyclopentadienyl and metal is recognized as a very strong covalent bond that confines the cyclopentadienyl collapse to metal core, and the cyclic structure facilitates the formation of graphite. In contrast, the acetylacetonate groups intend to combine randomly due to their open-loop structure. Moreover, for open-loop structures such as acetylacetonate groups, metal catalysis also affects the growth trend, of which Ni is more likely to induce the formation of carbon nanotubes relative to Fe. This work can provide a good reference for the synthesis of M@CNPs with controllable morphology.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Qixuan Lin,Huiling Li,Junli Ren,Aojie Deng,Weiying Li,Chuanfu Liu,Runcang Sun
A feasible approach to produce xylooligosaccharides (XOS) using organic acids as catalysts by microwave-induced hydrolysis of different hemicelluloses was developed. The effects of different acids (oxalic acid, maleic acid, citric acid and sulfuric acid), acid concentration, reaction temperature and reaction time on the hemicelluloses hydrolysis were investigated. Results demonstrated that organic acid was more beneficial to the XOS production than the conventional sulfuric acid. Higher acid concentration, higher reaction temperature and longer reaction time accelerated the further depolymerization of XOS to form monosaccharide. Response surface methodology was employed to optimize the reaction conditions (temperature and time) for the production of XOS from beechwood xylan (BX), corncob hemicelluloses (CH) and recovered hemicelluloses from the industrial waste liquor of dissolving pulp (RH), respectively. The predicted highest XOS yields were achieved to 39.31% (126.54 °C–7.95 min), 27.29% (120.00 °C–0 min), 30.32% (122.63 °C–15.85 min), respectively, being close to the experimental value (39.42%, 27.46% and 30.89%) from BX, CH and RH, indicating the fitted models of XOS yield were in good agreement with the experimental results.
研究领域:
生物化学
·
食品科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 217
·期 23
·2626-2634
·
IF 2.495
Haiyan Du,Xiaoxiao Liu,Yulong Yu,Yuyu Xu,Yonghong Wang,Zhenhai Liang
Recently, different stimuli triggered shape memory polymer composites (SMPC) have received much research interest. However, most shape memory effects (SME) in polymer composites are mainly caused by introducing different functional inorganic fillers into polymer matrix. In the present work, the special structure of poly(ionic liquids), the heating effect of microwaves (MW), and the mechanism of SMPs are combined to design MW induced SMPC completely based on polymers, poly(ionic liquid)/poly(vinyl alcohol) (PIL/PVA) polymer networks. PILs contain anion cation pairs, which have strong MW absorption capability due to their dielectric properties. Polymer composites absorb MW energy under irradiation and generate MW heating, which could provide the required energy for shape recovery. The functional ionic liquid monomer (MIL) styrene imidazole ([VBBI][BF 4 ]) is synthesized and polymerized. Then, PIL is mixed into PVA solution, which is crosslinked with glutaraldehyde to form P[VBBI][BF 4 ]/PVA polymer networks. 1 H NMR is used to characterize the structure of the synthesized styrene imidazole ILM and PIL. A bending test is applied to quantitatively characterize SMEs, which are affected by the PIL content in the composites and the applied MW power output. The present work combines the advantages of microwaves with PILs, opening up an efficient and environmentally friendly field for SMPs.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2015
·
IF 1.903
Haiyan Du,Zhen Song,Jingjing Wang,Zhenhai Liang,Yinghua Shen,Feng You
Microwave (MW) induced shape-memory composites based on poly(vinyl alchohol) (SM-PVA) are prepared by introducing silicon carbide (SiC, a strong MW absorbing material) into polymer matrix. Silane coupling agent 3-triethoxysilylpropylamine is used to modify inorganic particles in order to improve SiC dispersion in PVA matrix. Fourier transform infrared reveals the successful surface modification of SiC. Bending test is carried out to quantitatively characterize shape-memory effect, which is affected by SiC content and the applied MW output power. Apart from the expected good MW-induced shape memory effect, SM-PVA composites also have good mechanical properties. On the basis of the wide medical applications of PVA and MW, the present studied composites have great potential applications in the field where fast shape recovery but indirect heating is required.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Lili Ling,Yawei Feng,Hao Li,Yao Chen,Jieya Wen,Jian Zhu,Zhenfeng Bian
In this work, Ag/TiO 2 composite was prepared by photo-reduction method. The study of photocatalytic degradation of different organic pollutants found that microwave can enhance the photocatalytic degradation rate . Further studies have shown that photo-generated holes are the main active species involved in photocatalytic degradation. Under microwave irradiation , silver nanoparticles can not only promote the charge separation process, but also enhance the adsorption of organic pollutants on the surface of TiO 2 .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Shiyuan Liu,Lefu Mei,Xiaoliang Liang,Libing Liao,Guocheng Lv,Shuaifei Ma,Shiyao Lu,Amr Abdelkader,Kai Xi
Microwave-induced catalytic degradation is considered amongst the most efficient techniques to remove antibiotic such as chlortetracycline from contaminated water. Described here is a new microwave-induced oxidation catalyst based on carbon nanotubes (CNTs) decorated uniformly with nanoparticles of Fe3O4. The combination of dielectric loss and magnetic loss of the material contributed to its stronger microwave absorption and the ability to produce more “hot spots”. These hot spots promoted the oxidation of common antibiotics such as chlortetracycline, tetracycline, and oxytetracycline under microwave irradiation. Experiments with the addition of scavenger showed that hydroxy radicals (•OH) together with superoxide radicals (•O2–) contributed to the antibiotics removal as well. The final degradation products included CO2 and NO3– as confirmed by mass spectroscopy and ion chromatography analyses. The results indicated that the Fe3O4/CNTs was an efficient catalyst for microwave-induced oxidation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers of Chemical Science and Engineering
·
2019
·Vol. 13
·期 4
·759-771
·
IF 2.809
Gao Xin,Shu Dandan,Li Xingang,Li Hong
Microwave-induced film evaporation separation process has been reported recently to separate the polar/nonpolar mixture. However, the efficiency of the separation is still too low for practical applications, which requires further enhancement via different strategies such as optimization design of evaporator structure. In addition the depth understanding of the separation mechanisms is great importance for better utilization of the microwave-induced separation process. To carry out these investigations, a novel microwave-induced falling film evaporation instrument was developed in this paper. The improvement of the enhancement effect of microwave-induced separation was observed based on the improved film evaporator. The systematic experiments on microwave-induced separation with different binary azeotropic mixtures (ethanol-ethyl acetate system and dimethyl carbonate (DMC)-H 2 O system) were conducted based on the new evaporator. For the ethanol-ethyl acetate system, microwave irradiation shifted the direction of evaporation separation at higher ethanol content in the starting liquid mixture. Moreover, for DMC-H 2 O system microwave-induced separation process broke through the limitations of the traditional distillation process. The results clearly demonstrated the microwave-induced evaporation separation process could be commendably applied to the separation of binary azeotrope with different dielectric properties. Effects of operating parameters are also investigated to trigger further mechanism understanding on the microwave-induced separation process.
研究领域:
化学工程
·
分离科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）