ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 5
·5094-5110
·
IF 2.914
Zhang Mengjiao,Zhu Liyun,He Changhua,Xu Xiaojun,Duan Zhengyang,Liu Shuli,Song Mingyao,Song Shumin,Shi Jiemei,Li Yu’e,Cao Guangzhu
In this study, the novel adsorbent PVA-TA-βCD was synthesized via thermal cross-linking between polyvinyl alcohol and β-cyclodextrin. The characterization methods SEM-EDS, FTIR, and XPS were adopted to characterize the adsorbent. The effect of pH, contact time, initial concentrations, and temperature during the adsorption of Pb(II), Cd(II), and Mn(II) onto the PVA-TA-βCD was also investigated. In a single-component system, the data fitted well to pseudo-second-order, and film diffusion and intra-particle diffusion both played important roles in the adsorption process. As for isotherm study, it showed a heterogeneous adsorption capacity of 199.11, 116.52, and 90.28 mg g −1 for the Pb(II), Cd(II), and Mn(II), respectively. Competition between the ions existed in a multi-component system; however, owing to the stronger affinity of the PVA-TA-βCD for Pb(II) relative to Cd(II) and Mn(II), the Pb(II) adsorption onto the PVA-TA-βCD was less affected by the addition of the other metals, which could be effectively explained by the hard and soft acid and base theory (HSAB). Furthermore, PVA-TA-βCD showed good reusability throughout regeneration experiments.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Man Zhang,Jianping Gao,Wei Hong,Xiaoxue Wang,Qiang Tian,Zhaolin An,Luyao Wang,Hongduo Yao,Yu Liu,Xiaoxiang Zhao,Haixia Qiu
The development of oxygen reaction reduction (ORR) electrocatalysts that are low-cost, highly-active and have long-term stability for use in energy conversion and storage applications such as fuel cells and metal-air batteries is very important. In this paper, a facile one-step pyrolysis method was used to prepare bamboo-like N-doped carbon nanotubes (BNCNTs) as effective ORR electrocatalysts. Manganese and cobalt salts were used as the metal precursors, and urea was the C and N source. The resulting catalysts were characterized by the scanning electron microscopy , high resolution-transmission electron microscopy, X-ray photoelectron spectroscopy, Raman microscopy and X-ray power diffraction. The BNCNTs contained Mn and Co nanoparticles that were coated with graphitic carbon. The electrochemical performances of the catalysts in alkaline media were evaluated using cyclic voltammetry , linear sweep voltammetry and chronoamperometry . The BNCNTs prepared with a Mn to Co molar ratio of 1:1 at 800 °C had the best catalytic activity. The reaction followed a quasi-4 electron reaction pathway with a smaller Tafel slope (57.5 mV dec −1 ) than that of the commercial Pt/C (72.8 mV dec −1 ). In addition, the limiting current density, durability and methanol crossover resistance were all superior to those of Pt/C. The above results indicate that Mn/Co-BNCNTs-800 is an active electrocatalyst with earth-abundant non-precious elements for ORR.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 11
·1-9
·
IF 5.705
He Lifang,Bao Zhijun,Zhang Kui,Yang Danting,Sheng Bingbing,Huang Rui,Zhao Ting,Liang Xiaochen,Yang Xingjie,Yang Annan,Zhang Cheng,Cui Ping,Zapien Juan Antonio,Zhou Haibo
A ratiometric probe is described for the fluorometric determination of Cu(II) ions based on their quenching effect on the luminescence of dually-emitting quantum dots (QDs). ZnS QDs were doped with Mn(II) and subsequently modified with mercaptopropionic acid to give the QD probe which consists of a sole fluorophore but has two emission peaks (at 430 and 590 nm under 310 nm excitation, respectively). On addition of Cu(II) ions, the 590 nm band is quenched while the 430 nm band exhibits a little change. The changes in the intensity ratios of the yellow and the purple bands increases linearly in the 0 to 3.0 μM Cu(II) concentration range, and the detection limit reached 14 nM. The QD probe was validated and successfully applied to the determination of Cu(II) in spiked real water samples.
Mn-doped ZnS (ZnS:Mn(II)) quantum dots were synthesized with yellow fluorescence. After the modification of 3-mercaptopropionic acid (MPA), ZnS:Mn(II) was transferred to aqueous phase and became MPA modified Mn-doped ZnS (MPA- ZnS:Mn(II)). The fluorescence was changed to purple upon the addition of copper ions because the yellow band was largely quenched while the purple band only changed a little.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2018
·
IF 1.795
Qiu-hang CHEN,Shi-liang MEI,Wu YANG,Wan-lu ZHANG,Gui-lin ZHANG,Jia-tao ZHU,Rui-qian GUO
Color tunable quantum dots (QDs) based on the Cu, Mn, Ag co-doped ZnInS core and ZnS outer-shell were synthesized by using an eco-friendly method. Core-shell doped QDs with the average size of 3.85 nm were obtained by using a one-pot synthesis followed by a hot injection with n -dodecanethiol (DDT) and oleylamine (OLA) as stabilizers in oil phase. Cu, Mn and Ag ions were introduced as single-dopant or co-dopants during the synthesis, providing an effective means to control the emission color of the QDs. The as-synthesized QDs showed photoluminescence emission ranging from green (530 nm) to near-red (613 nm), adjusted by doping components, dopant concentration, and Zn/In ratio. Importantly, quasi-white emission has been achieved by controlling the concentration of co-doped metal ions (Mn, Cu and Ag). The primary results demonstrated the promising potential of co-doped QDs as alternative materials for future high quality white LED applications.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Xia Xu,Zhuo Wang,Pengpeng Lei,Yingning Yu,Shuang Yao,Shuyan Song,Xiuling Liu,Yue Su,Lile Dong,Jing Feng,Hongjie Zhang
Novel flower-like α-NaYb(Mn)F4:Er3+/Tm3+@NaYF4 upconversion nanoparticles (UCNPs) as luminescent nanothermometers have been developed by combining liquid–solid solution hydrothermal strategy with thermal decomposition strategy. Under 980 nm excitation, they exhibit intense upconversion luminescence and temperature-dependent upconversion luminescence over a wide temperature range. The influence of temperature on “band-shape” upconversion luminescence (UCL) spectra and the intensity of emission bands are analyzed and discussed in detail. We further successfully test and verify that intensity ratios REr of 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 and RTm of 1G4 → 3H5 and 3H4 → 3H6 are sensitive to temperature, and the population of active ions follows Boltzmann-type population distribution very well. These luminescent nanothermometers could be applied over a wide temperature range from 123 to 423 K with high sensitivity, which enable them to be excellent candidates for temperature sensors.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Guangdi Nie,Xiaofeng Lu,Maoqiang Chi,Mu Gao,Ce Wang
Improving the conductivity and specific surface area of electrospun carbon nanofibers (CNFs) is beneficial to a rapid realization of their applications in energy storage field. Here, a series of one-dimensional C/MO x (M = Mn, Cu, Co) nanostructures are first prepared by a simple two-step process consisting of electrospinning and thermal treatment. The presence of low-valence MO x enhances the porosity and conductivity of nanocomposites to some extent through expanding graphitic domains or mixing metallic Cu into the CNF substrates. Next, the C/MO x frameworks are coated with MnO 2 nanosheets/nanowhiskers (C/MO x @MnO 2 ), during which process the low-valence MO x can partly reduce KMnO 4 so as to mitigate the consumption of CNFs. When used as active materials for supercapacitor electrodes, the obtained C/MO x @MnO 2 exhibit excellent electrochemical performances in comparison with the common CNFs@MnO 2 (CM) core-shell electrode due to the combination of desired functions of the individual components and the introduction of extra synergistic effect. It is believed that these results will provide an alternative way to further increase the capacitive properties of CNFs- or metal oxide-based nanomaterials and potentially stimulate the investigation on other kinds of C/MO x composite nanostructures for various applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 44
·15512-15519
·
IF 4.029
Lili Yao,Wenxiu Yang,Huiling Liu,Jianbo Jia,Guohua Wu,Dan Liu,Ting Liu,Taixing Tan,Cheng Wang
The design of efficient mixed Mn–Co oxides as oxygen reduction reaction (ORR) electrocatalysts in alkaline media has been boosted nowadays. Recently, multivariant MOFs have been demonstrated as versatile precursors to construct these mixed metal oxides. Herein, we synthesized four mixed Mn–Co oxide samples via simply annealing their MIL-53 precursors with different Co/Mn molar ratios. These four samples were dominated by three kinds of Mn–Co spinel phases. The mixed Mn–Co oxides showed enhanced ORR performances compared with the single metal counterparts in alkaline media. In particular, the sample containing a pure MnCo2O4 phase exhibited the highest activity with a half-wave potential of 0.772 V (vs. RHE), only 40 mV negative compared with that of commercial Pt/C. The H2O2 yield was calculated to be below 12.1%, corresponding to the high diffusion-limited current density along with the high electron transfer number. The surface defects, active Mn4+/Mn3+ and electrochemically active surface area together affected the ORR performances of these mixed Mn–Co oxides. The present work highlights the facile controllability of divalent MIL-53 analogues for highly efficient mixed Mn–Co oxides in ORR electrocatalysis.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2017
·
IF 4.339
Baohuai Zhao,Rui Ran,Xingguo Guo,Li Cao,Tengfei Xu,Ze Chen,Xiaodong Wu,Zhichun Si,Duan Weng
Mn/Ce/Ti and Mn/Ce/Nb/Ti catalysts were synthesized using a precipitation method and their catalytic activities for NO selective reduction with NH 3 at low temperatures were evaluated. Nb doping not only improved the activity of the catalyst over a wide temperature range but also restricted the generation of NO 2 and N 2 O. The Mn/Ce/Nb/Ti catalyst displayed 100% NO conversion from 150 to 250 °C and >90% N 2 selectivity below 250 °C. The specific surface area of the catalyst was increased and its surface acidity was strengthened after Nb doping. Moreover, Nb doping increased the NO oxidation ability and lowered the NH 3 oxidation activity of the catalyst. All the above factors contributed to enhancing the overall NH 3 -SCR performance of the Mn/Ce/Nb/Ti catalyst compared with that of the Mn/Ce/Ti one. The long-term stability and resistance to H 2 O and SO 2 of the Mn/Ce/Nb/Ti catalyst were also evaluated.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 39
·24353-24358
·
IF 3.108
Pingge He,Qun Huang,Boyun Huang,Tengfei Chen
Ni–Co–Mn multi-component metal oxides with various morphologies for high-performance supercapacitor electrodes were controllably synthesized on carbon cloth through a facile hydrothermal method followed by a subsequent annealing process. The crystalline structure, morphology and electrochemical property of the metal oxides can be manipulated by simply adjusting the Ni/Co/Mn ratio in the solution. The metal oxide prepared in the solution containing a Ni/Co/Mn ratio of 1/1/2 presents a structure consisting of nanosheets and nanoneedles, and exhibits the highest specific capacitance of 1434.2 F g−1 at a current density of 2 mA cm−2, desirable rate capability and excellent cyclic stability with a capacitance retention of 94% over 3000 cycles. To demonstrate practical application, flexible asymmetric supercapacitors based on such metal oxides were prepared and show high capacitance, low internal resistance, excellent cyclic stability and outstanding flexibility, indicating great potential as high-performance energy storage devices.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2016
·
IF 7.354
Haoran Yuan,Xiang Fang,Qiyi Ma,Jianyong Mao,Kexian Chen,Zhirong Chen,Haoran Li
The mechanism for aerobic oxidation of methylaromatic compounds using Co(CH 3 COO) 2 –Mn(CH 3 COO) 2 –KBr was further studied. The experimental results suggested that the intermediates (aromatic alcohols) are unexpectedly inert to direct oxidation via Co–Mn–Br catalysts under moderate conditions. In addition, it is found that both aromatic and aliphatic alcohols can inhibit the oxidation of the substrates and other intermediates (aromatic esters, aromatic aldehydes). UV–vis spectra indicated that oxidation from Co(II) to Co(III) would be interrupted in the presence of a given amount of alcohol. A plausible mechanism was also proposed. The intermediates analyzed by LC–MS and control experiments showed that aromatic alcohols prefer to undergo esterification rather than being directly oxidized as described in previous studies, and aromatic acetates are subsequently oxidized to corresponding aldehydes. According to the new mechanism, a strategy of highly selectively synthesizing aromatic alcohols and aldehydes from corresponding methylaromatic compounds was designed. The selectivities of aromatic alcohols and aldehydes could also be tuned by the added amount of CH 3 COOK.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Xiaoxiang Cheng,Heng Liang,Fangshu Qu,An Ding,Haiqing Chang,Bin Liu,Xiaobin Tang,Daoji Wu,Guibai Li
Mn oxide incorporated membranes were fabricated by incorporation of MnO 2 particles prepared using different methods (C-MnO 2 , M-MnO 2 and S-MnO 2 ) on the surface of ceramic ultrafiltration membranes. Initially, the physicochemical properties of prepared MnO 2 particles were systematically analyzed, and S-MnO 2 exhibited the best dispersibility and smallest particle size. Scanning electron microscopy and atomic force microscopy analyses demonstrated that the morphologies and topographies of the fabricated membranes were significantly affected by the preparation method of MnO 2 particles. Subsequently, sodium alginate was employed to investigate the antifouling properties of the fabricated membranes. Although the incorporation of MnO 2 particles increased membrane intrinsic resistance to varying degrees, M-MnO 2 and S-MnO 2 apparently mitigated both reversible and irreversible fouling in the presence of ozone, whereas C-MnO 2 exerted a minor influence. Further, p -chloronitrobenzene was used to study the activity of fabricated membranes in catalytic ozonation. C-MnO 2 , M-MnO 2 and S-MnO 2 incorporated membranes exhibited enhanced activities with the removal efficiencies of 51.7%, 61.5% and 68.0%, respectively. The results indicated that the preparation method of S-MnO 2 was most appropriate for the preparation of highly dispersive MnO 2 particles to incorporate with ceramic membranes. Results in this study contribute to the fabrication of Mn oxide incorporated membranes with an efficient and convenient way, and provide relevant information on their actual application.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Yingjie Chen,Shiben Liu,Liyan Yu,Qiuhong Liu,Yongtao Wang,Lifeng Dong
Nanoparticles with core–shell or hollow interiors have immense potential for catalysis. Herein, Ag@M x Fe 3− x O 4 (M = Co, Mn) core–shell nanoparticles were firstly synthesized through a seed-mediated method. These particles were then loaded onto carbon catalyst supports to form Ag@M x Fe 3− x O 4 /C. Then, hollow-M x Fe 3− x O 4 /C was prepared with the diffusion of Ag from Ag@M x Fe 3− x O 4 /C in saturated NaCl solution at room temperature . As a result, Ag@MnFe 2 O 4 /C demonstrates better oxygen reduction reaction (ORR) activity than Ag@CoFe 2 O 4 /C and other Ag@Mn x Fe 3− x O 4 /C with various Mn/Fe ratios. Moreover, Ag@MFe 2 O 4 /C shows superior ORR catalytic activities over hollow-MFe 2 O 4 /C, which can be due to electronic coupling between Ag core and MFe 2 O 4 shell. Furthermore, Ag@MnFe 2 O 4 /C catalysts demonstrate high durability for the ORR in alkaline media and insensitivity to methanol. These findings will provide helpful guidance for design and fabrication of carbon-supported core–shell catalysts for ORR in the future.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）