ACS Sustainable Chemistry & Engineering
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2015
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IF 4.642
Yuchao Wang,Da Shi,Shengyang Tao,Wentong Song,Hongmin Wang,Xinkui Wang,Guangtao Li,Jieshan Qiu,Min Ji
A general, green chemistry approach is developed for the immobilization of inorganic catalysts in monolithic porous flow-reactors for continuous flow reactions, in which pyrogallol (PG) acts as an assistant layer for the in situ immobilization of various catalysts on the inner pore surface of the flow-reactor. Au nanoparticles (AuNPs), Al2O3, and phosphotungstic acid (HPW) are selected as examples of noble metals, metal oxides, and polyoxometalate (POM) type catalysts, respectively, and the corresponding flow-reactors show high catalytic performance in continuous flow hydrogenation reactions, esterification reactions, and Knoevenagel reactions, respectively. These reactions are important in the treatment of environmental contaminants and in the chemical industry. In addition, multiple monolithic flow-reactors can be assembled together for efficient performance of multi-step cascade reactions.
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CARBOHYDRATE POLYMERS
·
2015
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IF 4.074
Wei Yan,Chang Chen,Ling Wang,Dan Zhang,Ai-Jun Li,Zheng Yao,Li-Yi Shi
The emphasis of science and technology shifts toward environmentally friendly and sustainable resources and processes. Herein, we report a facile, one-pot and green synthesis of biomaterial-supported gold nanoparticles (AuNPs) with superior catalytic activity. Cellulose nanocrystal (CNC)-supported AuNPs were prepared by heating the aqueous mixture of HAuCl 4 , CNCs and polyethylene glycol, avoiding toxic chemicals, extreme condition and complicated procedure. The resultant CNC-supported AuNPs exhibited catalytic activities for the reduction of 4-nitrophenol by sodium borohydride. The maximum apparent rate constant reached 1.47 × 10 −2 s −1 , and the turnover frequency reached 641 h −1 . The superior catalytic performance can be ascribed to the large amount of highly dispersed AuNPs with few nanometers in size which are loaded on CNCs. About 90% of the AuNPs are smaller than 10 nm, and nearly 60% of the AuNPs are smaller than 5 nm. The synthesis is eco-friendly, facile and low-cost, thus has great potential for industrial and medical applications.
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Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 48
·18990-19002
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IF 8.262
Liguang Dou,Hui Zhang
A series of novel hierarchical nanosheet array-like hybrids xCu-LDH/rGO (xCu-LDH: CuxMg3−xAl-layered double hydroxide (x = 0.5, 1.0, and 1.5), rGO: reduced graphene oxide) were assembled via a facile and green aqueous-phase coprecipitation method. Systematic characterization suggests that the hybrids were constructed by hexagonal LDH nanoplates (∼70 nm × 4.5 nm) interdigitated vertical to the surface of single-layer rGO. All the xCu-LDH/rGO hybrids exhibit a remarkable higher activity for catalytic reduction of 4-nitrophenol (4-NP) compared with pure Cu-LDH, commercial Pt/C and other recently reported Cu-related catalysts. These findings were carefully explained by deep study of the catalyst treated with NaBH4, and the xCu-LDH/rGO hybrids as a potential Cu2O reservoir were revealed for the first time. Typically for 1.0Cu-LDH/rGO, a part of Cu2+ ions on LDH layers were instantaneously in situ reduced to well-dispersed ultrafine Cu2O nanoparticles (∼6.8 nm) by NaBH4 in an aqueous reduction system and thus formed relatively strong interaction between Cu2O and LDH/rGO greatly favoring enhanced activity for the reduction of 4-NP, other nitroarenes and organic dyes at room temperature. The excellent activity of the xCu-LDH/rGO hybrids can be attributed to the possible Cu2O–Cu-LDH–rGO three-phase synergistic effect, increased adsorption capacity for reactants via π–π stacking, and unique nanoarray-like morphology of the hybrids. Moreover, the 1.0Cu-LDH/rGO can be cycled for 20 runs without significant loss of activity, giving the hybrid long-term stability.
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CHINESE JOURNAL OF CATALYSIS
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2016
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IF 2.628
Haijun Chen,Chao Liu,Min Wang,Chaofeng Zhang,Gao Li,Feng Wang
Well-defined gold nanoclusters with average size less than 2 nm have emerged as a new and novel catalyst. The gold nanocluster loaded on the oxide surface usually aggregates to larger particles at high temperature (> 300 °C), which is caused by the removal of the surface ligands. We herein present a novel method to prepare Au 25 cluster catalyst (∼1.3 nm) with high thermal stability (up to 400 °C). Au 25 @SiO 2 is synthesized via a co-hydrolyzing reaction of Au 25 [SC 3 H 6 Si(OCH 3 ) 3 ] 18 and tetraethyl orthosilicate, and then it is treated at different temperature (e.g., 200, 300, 400 °C) in air to remove the organic ligands. Au 25 @SiO 2 is well characterized by transmission electron microscopy, ultraviolet-visible spectroscopy and diffuse reflectance UV-vis spectroscopy. Further, the Au 25 @SiO 2 catalysts are investigated in the hydrogenation of p -nitrophenol into p -aminophenol.
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Chemistry-An Asian Journal
·
2016
·Vol. 11
·期 24
·3534-3540
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IF 4.592
Jiao Jiao,Haiyan Wang,Wanchun Guo,Ruifei Li,Kesong Tian,Zhaopeng Xu,Yin Jia,Yuehao Wu,Ling Cao
Graphical Get the yolk ! A hierarchical yolk–shell Fe@SiO 2 /Ni catalyst with an inner movable Fe core and an ultrathin SiO 2 /Ni shell assembled from nanosheets was synthesized by a self-templating reduction strategy (see figure). The spatial confinement of 4 nm Ni nanoparticles in ultrathin SiO 2 nanosheets (2.6 nm thick) could prevent their agglomeration during catalytic reductions and expose the abundant active Ni sites to reactants, to provide high activity and stability. Ni-based magnetic catalysts exhibit moderate activity, low cost, and magnetic reusability in hydrogenation reactions. However, Ni nanoparticles anchored on magnetic supports commonly suffer from undesirable agglomeration during catalytic reactions due to the relatively weak affinity of the magnetic support for the Ni nanoparticles. A hierarchical yolk–shell Fe@SiO 2 /Ni catalyst, with an inner movable Fe core and an ultrathin SiO 2 /Ni shell composed of nanosheets, was synthesized in a self-templating reduction strategy with a hierarchical yolk–shell Fe 3 O 4 @nickel silicate nanocomposite as the precursor. The spatial confinement of highly dispersed Ni nanoparticles with a mean size of 4 nm within ultrathin SiO 2 nanosheets with a thickness of 2.6 nm not only prevented their agglomeration during catalytic transformations but also exposed the abundant active Ni sites to reactants. Moreover, the large inner cavities and interlayer spaces between the assembled ultrathin SiO 2 /Ni nanosheets provided suitable mesoporous channels for diffusion of the reactants towards the active sites. As expected, the Fe@SiO 2 /Ni catalyst displayed high activity, high stability, and magnetic recoverability for the reduction of nitroaromatic compounds. In particular, the Ni-based catalyst in the conversion of 4-nitroamine maintained a rate of over 98 % and preserved the initial yolk–shell structure without any obvious aggregation of Ni nanoparticles after ten catalytic cycles, which confirmed the high structural stability of the Ni-based catalyst.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 25
·20567-20576
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IF 2.741
Yao Lingdan,Wang Lixiao,Cheng Guanghuan,Huang Qian,Hu Baolan,Lu Jingrang,Lou Liping
In a previous study, we found that rice-straw biochar degraded and removed hydrophobic organic contaminants (HOCs) through coupled adsorption-biodegradation. However, few studies have determined whether biochar affects HOC isomer degradation and isomer-selective biodegradation or whether biochar can alter HOC isomer features, resulting in changes to HOC isomer residues in water environments. In this study, the effects of biochar at two dosages (0.001 and 0.01 g) on the biodegradation of ten isomers of a typical xenoestrogen of nonylphenol (NP) were evaluated. The results revealed that there were no effects of biochar on the adsorption of NP isomers. However, biochar addition affected the biodegradation of a specific isomer without altering the features of the NP isomers. The treatment of NP isomers with Pseudoxanthomonas sp . yielded degradation ratios ranging from 60.7 to 100%. At 0.001 g biochar treatment, the degradation of eight NP isomers was enhanced (except for NP 194 and NP 193a+b ) due to their bulky structures. The degradation of the ten NP isomers was inhibited when 0.01 g biochar was added. These findings characterized the effects of biochar on NP isomer contaminants and provided basic information for the application of biochar for the remediation of NP isomer contaminants.
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NEW JOURNAL OF CHEMISTRY
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2017
·Vol. 41
·期 16
·8399-8406
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IF 3.269
Longgang Wang,Qinghua Yang,Yanshuai Cui,Dawei Gao,Jianxin Kang,Haotian Sun,Linlin Zhu,Shengfu Chen
The development of stable and biocompatible gold nanoparticles has been drawing great interest. Dendrimers could be used as templates to entrap gold nanoparticles. Herein, dendrimer templates were prepared by the modification of generation 5 polyamidoamine (G5 PAMAM) dendrimers with maleic anhydride and cysteamine. Then modified dendrimer-encapsulated gold nanoparticles (Au-G5MC NPs) were formed by incubation of the templates with chloroauric acid and reduction with sodium borohydride. The resulting Au-G5MC NPs showed high stability, biocompatibility, and catalytic efficiency in water, which is ascribed to the single zwitterionic layer composed of amine and carboxyl groups. The single zwitterionic layer was shown to provide the Au-G5MC NPs with excellent stability in both phosphate-buffered saline and fibrinogen solutions. The mixed solution of Au-G5MC NPs with fibrinogen remained stable within 24 h, while the mixed solution of G5 PAMAM dendrimer-entrapped gold nanoparticles (Au-G5 NPs) with fibrinogen formed obvious aggregates immediately. Au-G5MC NPs displayed little cytotoxicity (>90% cell viability) against HeLa cells up to 100 μg mL−1, while Au-G5 NPs showed obvious cytotoxicity (60% cell viability). In addition, Au-G5MC NPs displayed high catalytic efficiency for the reduction reaction of 4-nitrophenol (4-NP) in water. This method can be used to prepare a variety of highly stable, biocompatible, and efficient dendrimer-encapsulated catalysts.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2017
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IF 2.714
Peng Li,Sen Li,Yu Wang,Yu Zhang,Guo-Zhi Han
Increasing application of noble-metal nanoparticles (MNPs) urges the development of a nontoxic and environmentally friendly synthesis methodology. In this paper,using β-Cyclodextrin (β-CD) as reducer and stablizer, a green synthetic approach of monodispersed silver nanoparticles (AgNPs) with diameter between 10–25 nmin aqueous alkaline medium is reported. By varying the molar ration of β-CD/AgNO 3 , the size of as-prepared silver particles can be readily controlled. Furthermore, the formation mechanism of the AgNPs was discussed. On the basis, the catalytic activity of the as-prepared AgNPs was studied toward reduction of p -nitrophenol by NaBH 4 . The experimental results shown that surface modified by β-CD can improve the catalytic activity of the silver nanoparticles.
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BIORESOURCE TECHNOLOGY
·
2016
·
IF 4.917
Danlian Huang,Xingmeng Qin,Piao Xu,Guangming Zeng,Zhiwei Peng,Rongzhong Wang,Jia Wan,Xiaomin Gong,Wenjing Xue
A composting study was performed to investigate the degradation of 4-nonylphenol (4-NP) in river sediment by inoculating Phanerochaete chrysosporium ( Pc ). Pc was inoculated into composting Reactor A, C and D, while Reactor B without inocula was used as control. The results showed that composting with Pc accelerated the degradation of 4-NP, increased the catalase and polyphenol oxidase enzyme activities in contaminated sediment. The dissipation half-life (t 1/2 ) of 4-NP in Reactor A, C and D with inocula of Pc were 2.079, 2.558, 2.424 days, while in Reactor B without inocula of Pc it was 3.239 days, respectively. Correlation analysis showed that the contents of 4-NP in sediment in Reactor A and D were negatively correlated with the actives of laccase, whereas no obvious correlation was observed in Reactor B and C. All these findings also indicated that Pc enhanced the maturity of compost, and the best composting C/N ratio was 25.46:1.
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MICROCHIMICA ACTA
·
2017
·Vol. 185
·期 1
·1-8
·
IF 4.58
Wang Juntao,Jiao Caina,Li Menghua,Wang Xiaolan,Wang Chun,Wu Qiuhua,Wang Zhi
Porphyrin-based porous organic polymers (P-POPs) are amorphous polymers linked by strong covalent bonds between the porphyrin subunits that act as building blocks. The authors describe a magnetic P-POP that possesses high surface area, a highly porous structure, and strong magnetism. The MP-POP was employed as a magnetic sorbent for the extraction of benzoylurea insecticides from cucumber and tomato samples prior to their determination by HPLC. The sorbent has a typical sorption capacity of 1.90–2.00 mg∙g −1 . The method exhibits a good linear range (0.8–160 ng·g −1 ), low limits of detection (0.08–0.2 ng·g −1 ), and high method recoveries (81.8–103.5%) for cucumber and tomato samples. The MP-POP has different adsorption capabilities for the benzoylurea insecticides, phenylurea herbicides and phenols compounds, and the adsorption mechanism is found to be based on π-stacking, hydrogen-bonding, and hydrophobic interactions.
A novel magnetic porphyrin-based porous organic polymer was fabricated and used as the adsorbent for the efficient extraction of benzoylurea insecticides.
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TALANTA
·
2017
·
IF 4.162
Xiaofang Ma,Yali Wu,Samrat Devaramani,Caizhong Zhang,Qixia Niu,Mahgoub Ibrahim Shinger,Wenqi Li,Duoliang Shan,Xiaoquan Lu
The GO-COOH/AuNPs/ZnAPTPP nanocomposites were constructed using zinc monoamino porphyrin (ZnAPTPP) through π–π conjugation with carboxylated graphene oxide (GO-COOH) loaded with Au nanoparticles (AuNPs). Prepared materials were characterized by 1 H NMR spectra, UV–vis absorption spectroscopy and electrochemical impedance spectroscopy . ITO electrode surface was modified with the prepared nanocomposites showed a good photocurrent response when the bias potential, −0.1 V was applied. Nanocomposites modified ITO electrode exhibited good photo-response to the 4-nitrophenol (4-NP). ZnAPTPP were excited from HOMO to LUMO under light irradiation , the photoexcited electrons injected into the conduction band of GO-COOH, and then transferred to AuNPs further to the ITO. The presence of GO-COOH and AuNPs improved the separation of photogenerated charges due to their synergetic effect and excellent conductivity. Externally added 4-NP scavenges the photogenerated holes i.e. it acts as a sacrificial electron donor thereby it enhances the photocurrent of the system. Based on this interaction, a novel method for photoelectrochemical detection of 4-NP was developed with a linear range from 0.1 to 15 nmol/L (r = 0.996) and detection limit of 0.04 nmol/L (S/N = 3). Proposed method is simple and sensitive and this was successfully applied for the quantification 4-NP in river water sample matrices.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2017
·
IF 3.671
Ze-yong Tang,Dong Sun,Chun-wei Qian,Qi Chen,Shun-shan Duan,Sheng-yun Sun
Nonylphenol is an endocrine disrupting chemicals that can disrupt the organisms’ reproductive system, and exists widely in rivers and lakes. Lycium barbarum polysaccharide (LBP) is the main active constituent (about 10%) in Lycium barbarum , which is used to protect reproductive health. In this study, we investigated whether LBP can alleviate nonylphenol exposure induced testicular injury in juvenile zebrafish. We detected histological alteration, anti-oxidant enzyme profile and P450 gene transcription to assess LBP effect on testicular development. The GSI reduced significantly due to nonylphenol exposure, while LBP can improve the GSI. The densities of sperms increased and non-celluar zone decreased after LBP treatment. Meanwhile, Cyp11b gene was up regulated to NP group, and cyp19a gene was down regulated to NP group. In sum, the LBP could repair the testicular injury in zebrafish. This findings provide a basis research to remit the estrogen effect of artificial endocrine disruptor.
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