Molecular Catalysis
·
2018
·
IF 0
Cheng Liang,Xuefeng Li,Diefeng Su,Qiyi Ma,Jianyong Mao,Zhirong Chen,Yong Wang,Jia Yao,Haoran Li
Efficient aerobic oxidation has been developed for the selective preparation of a sequence of valuable p -hydroxybenzaldehydes from corresponding p -cresols, using a new magnetically separable catalyst of nano-structured cobalt–cobalt oxide/nitrogen-doped carbon (CoO x @CN) material. CoO x @CN showed high activity for the 2-methoxy-4-cresol oxidation to vanillin, giving great yield (90%) and with good turnover number (210), as well as other p -cresols in good to great yields. The catalytic performance was investigated and related to the structural, chemical and magnetic properties which determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). The effects of base to substrate molar ratio, catalyst concentration, temperature, and solvent on the conversion and selectivity patterns also have been studied. The investigation revealed that remarkable catalytic properties of CoO x @CN could be ascribed to the active species cobalt oxide, doped nitrogen and porous carbon with large surface area. The size of the catalyst is a key factor for catalyst performance. The ferromagnetic property of catalyst enables to recycle easily by an external magnetic field and reuse six successive times without significant activity loss.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2018
·Vol. 34
·期 6
·1051-1057
·
IF 1.248
Dong Yanying,Yu Ping,Sun Qilong,Lu Yang,Tan Zhenjiang,Yu Xiaopeng
Effective molecularly imprinted membranes(MIMs) were developed as an efficient adsorbent for the selective removal of p -hydroxybenzoic acid( p -HB) from acetylsalicylic acid(ASA, aspirin). The MIMs were grafted successfully from poly(vinylidene fluoride) microfiltration membranes via reversible addition-fragmentation chain transfer(RAFT) polymerization. The graft copolymerization of acrylic acid(AA) in the presence of template p -hydroxybenzoic acid led to molecularly imprinted polymer(MIP) film coated membranes. The obtained MIMs were characterized by scanning electron microscopy(SEM), Fourier transform infrared spectrophotometer(FTIR) and Raman spectra, and batch mode adsorption studies were carried out to investigate the specific adsorption equilibrium, kinetics and selective recognition properties of different MIMs. The kinetic properties of the MIMs could be well described by the pseudo-second-order rate equation. Selective permeation experiments were performed to evaluate the permeation selectivity of the p -HB imprinted membranes. The observed performances of the MIMs are applicable to the further purification of aspirin.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Ying Liu,Xiaoyan Chen,Yulin Yang,Yong Feng,Deli Wu,Shun Mao
Cobalt-based nanostructures have shown a great potential for radical production by activating persulfate (PS). Here, we report a facile strategy to synthesize nitrogen-doped porous Co@C nanoboxes (Co@NC) by pyrolysis of zeolitic imidazolate frameworks (ZIF-67), followed by partially etching away the metallic cobalt. With a nitrogen-enriched hollow porous carbon nanobox and embedded Co nanoparticles, the Co@NC shows high efficiency in PS activation for p-Chloroaniline (PCA) removal. The degradation study shows that a complete removal of high concentration PCA is done within two minutes, which is superior to most of the reported PCA removals with PS-based advanced oxidation processes (AOPs). More importantly, the Co@NC exhibits high catalytic activities in a wide range of pH from 5 to 9. The Co@NC also shows very limited Co 2+ release with a dissolution proportion of 0.28%, much lower than previously reported Co-based catalysts, and remains high efficiency after five successive reaction cycles. A heterogeneous activation mechanism though surface reaction is proposed, in which PCA firstly absorbs on the carbon nanobox surface, then being oxidized by generated radicals and non-radical species. The unique structure and outstanding performance of Co@NC catalysts present new insights in catalyst design for PS-based advanced oxidation for organic pollutants removal in waste water.
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JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2018
·Vol. 18
·期 12
·8307-8312
·
IF 1.354
Xu Peng,Chen Nannan,Lin Huan,Cen Changli,Wu Zhenguo,Xu Nanfang,Tang Jingen,Teng Zhaogang
Anchoring metal cores inside porous shells can endow metal catalyst with high selectivity and stability. Herein, multiple silver nanoparticles were successfully anchored in hollow mesoporous silica nanospheres (Ag@HMSNs) through a facile one-pot method. Polyacrylic acid aggregates self-assembled
in water/ethanol solvent were used as core templates and Ag nanoparticles captors, and hexadecyl trimethoxysilane (C16TMS) was used as the pore-making agent. The hollow cavity, encapsulated multiple Ag nanoparticles, and mesoporous silica shell of the Ag@HMSNs were confirmed by
X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and nitrogen sorption analysis. Just as expected, Ag nanoparticles (2–5 nm) were encapsulated in the cavity of hollow mesoporous silica nanospheres with the size of about 200 nm. The fabricated Ag@HMSNs showed excellent
performance for catalytic reduction of p-nitrophenol (4-NP). Also, catalytic activity of the Ag@HMSNs for 4-NP reduction was increased with the addition amount of the pore-making agents and surface areas. The superior catalytic performance was attributed to the unique structural features
of Ag@HMSNs architecture, in which the mesoporous shell provided readily accessible pathway for fast transport of reactants to the encapsulated Ag nanoparticles.
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xuan Fu,Long Sheng,Yisha Yu,Meihu Ma,Zhaoxia Cai,Xi Huang
Fluorescence resonance energy transfer (FRET), a near-field energy transfer from a fluorescent donor to a fluorescent acceptor within close proximity, has been widely used in biosensing. In this study, a rapid and universal sensor for the detection of ovalbumin (OVA) using nitrogen, oxygen, phosphoric co-doped CDs (NOP-CDs) and graphene oxide (GO) was established based on the FRET technology. First, novel NOP-CDs peak at 443 nm were synthesized by a one-pot hydrothermal method using egg powder and phosphorus acid. Then, in the absence of OVA, the fluorescence of OVA-antibody modified NOP-CDs was quenched by GO via electrostatic attraction and π-π stacking interaction due to the FRET effect. The introduced OVA competed to displace the GO by special binding with the anti-OVA, resulting in the recovery of the fluorescence. This sensor displayed a linear response to OVA from 0.5 to 15 μg/mL with a detection limit of 153 ng/mL and was successfully applied to the detection of the OVA sample with recoveries ranging from 99.25 to 118.90%. In summary, the green and easy-to-synthesize nano-material was used in this method, the accurate detection results, and the simple process exhibited the great potential of this method for practical applications.
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高影响因子
ANALYTICAL SCIENCES
·
2018
·Vol. 35
·期 2
·147-152
·
IF 1.355
Ju Yan Jun,Li Na,Liu Shi Gang,Fan Yu Zhu,Ling Yu,Xiao Na,Luo Hong Qun,Li Nian Bing
A fluorescence method for the determination of picric acid (PA) using phosphorus-doped carbon dots (P-CDs), synthesized from β-cyclodextrin and sodium pyrophosphate, is described. The P-CDs are very uniform and monodisperse with a diameter of about 2.8 nm. Under an excitation of 350 nm, the P-CDs emit bright blue fluorescence with an emission peak at 440 nm. The as-synthesized P-CDs serve as a sensitive, selective, and label-free fluorescent probe for the detection of PA. Based on an inner filter effect between PA and P-CDs, a linear response is obtained for PA from 0.1 to 10 μM with a detection limit of 82 nM. Finally, this sensing system has been demonstrated to have practicability for PA detection in the environmental water samples.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Haichao Fu,Peng Zhao,Shengjun Xu,Gong Cheng,Zhuoqian Li,Yi Li,Kai Li,Shuanglong Ma
The novel Fe 3 O 4 and porous biochar originated from Myriophyllum aquaticum composites (Fe 3 O 4 /MC) with graphitized structure, hierarchical porous and strong magnetism were used as efficient catalysts for degradation of organic pollutants in the presence of peroxymonosulfate (PMS). Three types of catalysts pyrolyzed at 600, 700, 800 °C manifested quit different PMS activation effect with the much better p-hydroxybenzoic acid (HBA) degradation efficiency at 700 and 800 °C than that of 600 °C, which was assigned to the high graphitization degree and mesopores ration of catalysts pyrolyzed at higher temperature. Based on radicals quenching experiments and electron paramagnetic resonance (EPR) analyses, the radical pathway dominated by surface-bound SO 4 − was the prevailing way while the non-radical pathway performed as electro-transfer was the recessive way during the degradation process. The large amount of surface-bound SO 4 − radicals were produced through the reduction of PMS by Fe(II), which was regenerated by participation of O 2 − /O 2 . The non-radical pathway was achieved by the graphitized structure which acted as electron transfer bridges accepting electrons form organic pollutants and denoting electrons to PMS. Six HBA intermediates were detected and the possible HBA degradation pathway was proposed tentatively. Consequently, the conversion of Myriophyllum aquaticum to composite catalyst provides a brand-new idea for efficient utilization of waste biomass in a high value-added way and simultaneously achieving the contaminants elimination.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Lin Shao,Yang Cao,Zhanying Li,Wenbin Hu,Shize Li,Lingbin Lu
Alginate was grafted with NIPAM and NHMAM successfully, and a new responsive copolymer, alginate-g-P(NIPAM-co-NHMAM), was obtained. A novel dual responsive polysaccharide-based aerogel with thermo/pH sensitive properties was designed from the copolymer as drug controlled release system. The chemical structure of the copolymer was characterized by FT-IR and 1 H NMR. Lower critical solution temperature (LCST) of the copolymer covered a wide temperature range from 27.6 °C to 42.2 °C, which could be adjusted with changing the ratio between NIPAM and NHMAM. The dual responsive aerogel had a three-dimensional network structure. As a drug controlled release system, the aerogel was high responsive to both temperature and pH with drug loading efficiency up to 13.24%. Above LCST, the aerogel had a faster drug release, and drug was completely released in neutral environment, while the drug release was obstructed in acid environment. Furthermore, the drug release mechanism of the aerogel was illuminated. These results indicated that the dual responsive aerogel was a promising candidate for drug carriers.
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PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2015
·Vol. 33
·期 6
·857-868
·
IF 1.835
Du Chun-hui,Ma Xu-min,Wu Chun-jin,Cai Mei-qiang,Hu Meng-xin,Wang Ting
Polymerizable ionic liquid copolymer P(MMA- co -BVIm-Br) was synthesized by radical polymerization technique, and characterized by Fourier transform infrared spectrometry (FTIR), 1 H Nuclear magnetic resonance ( 1 H-NMR) and gel permeation chromatography (GPC). The resulting copolymer was used to prepare poly(vinylidene fluoride) (PVDF) blend membranes via a phase inversion method. The effects of the copolymer on the polymorphism, surface wettability and zeta potential ( ζ ) of the blend membranes were investigated by ATR-FTIR, contact angle instrument and zeta potential analyzer. Scanning electron microscopy (SEM and SEM-EDS) was also applied to investigate the morphology and the surface element changes of the fabricated membranes. The results indicated that P(MMA- co -BVIm-Br) copolymer existed on the surface of the membrane which made the blend membrane have a positive surface during the experimental pH range. The copolymer was also in favor of the formation of β crystal phase in PVDF membranes. The contact angle experiment indicated that P(MMA- co -BVIm-Br) copolymer could switch the wettability of the blend membranes from hydrophilic to hydrophobic by exchanging Br − anion with PF 6
− . Compared with pure PVDF membranes, the water flux and water recovery flux of the blend membranes were enhanced obviously. The results from the flux recovery ratio (FR) and total fouling ratio ( R
t ) all suggested that the blend membranes had good anti-fouling properties.
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高影响因子
CATALYSIS LETTERS
·
2014
·Vol. 144
·期 6
·1001-1008
·
IF 2.291
Lin Chao,Tao Kai,Hua Dayin,Ma Zhen,Zhou Shenghu
Abstract Bimetallic Au 3 M (M = Ni, Co, Fe) nanoparticles (NPs) were synthesized by reducing a mixture of Au 3+ and metal cations (Ni 2+ , Co 2+ , Fe 3+ ) by butyllithium in the presence of oleylamine. Au 3 M NPs were then deposited onto a commercial SiO 2 support. The Au 3 M/SiO 2 samples were not particularly active in the catalytic reduction of p -nitrophenol unless they were converted into Au–MO
x
/SiO 2 after appropriate thermal treatment in air. The Au–MO
x
/SiO 2 catalysts showed good thermal stability and significantly higher p -nitrophenol conversions than Au/SiO 2 . Relevant characterization was conducted employing X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet–visible spectroscopy. Graphical Abstract
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Zhihai Cao,Hangnan Chen,Shudi Zhu,Zhijie Chen,Chang Xu,Dongming Qi,Ulrich Ziener
A convenient method based on the inverse miniemulsion technique was proposed to prepare raspberry-like Au/SiO 2 nanocomposite particles (NCPs). HAuCl 4 was incorporated into porous SiO 2 nano-supports through a sol–gel process of a silica precursor in inverse miniemulsions. Raspberry-like Au/SiO 2 NCPs were subsequently obtained through in situ reduction of the incorporated HAuCl 4 by hydrazine at the surface of SiO 2 nano-supports. Most of Au nanoparticles (NPs) were half-embedded in the SiO 2 nano-supports and were covered by a thin layer of porous SiO 2 , offering a good morphological stability to the Au/SiO 2 NCPs. The content of Au NPs of the Au/SiO 2 NCPs could be adjusted by the loading of HAuCl 4 . The influences of the HAuCl 4 loading on the particle size and particle morphology of the Au/SiO 2 NCPs, the pore properties of the SiO 2 nano-supports, as well as the properties of the Au NPs were systematically investigated. The formation mechanism of the raspberry-like Au/SiO 2 NCPs was discussed. All the synthesized Au/SiO 2 NCPs displayed a high catalytic activity towards the reduction of p -nitrophenol.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 119
·98492-98499
·
IF 3.84
Dechao Shi,Fanyong Yan,Tancheng Zheng,Yinyin Wang,Xuguang Zhou,Li Chen
A simple and rapid method for sensitive and selective detection of 2,4,6-trinitrophenol (TNP) was developed with the use of water-soluble carbon dots (CDs) as a nanosensor. The CDs with a fluorescence quantum yield of 21.8% are easily prepared by hydrothermal treatment of a sucrose phosphate solution. In this sensing system, the fluorescence of CDs would be significantly quenched by TNP, while other nitroaromatic derivatives and common reagents exhibited little influence on the detection of TNP. The efficient selective detection of TNP can be attributed to the fluorescence resonance energy transfer process (FRET). This phenomenon can be used for the selective sensing of TNP with a limit of detection of 16.9 nM and a linear range of 0.2–17.0 μM. The recovery result for TNP in real samples by this assay method was satisfying, demonstrating its potential application as a fluorescence sensor. Furthermore, the resulting CDs solution could replace traditional colorings and was successfully applied for Escherichia coli labeling and intracellular imaging.
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