CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Jianhua Zheng,Lei Zhang
In this study, a novel 3D magnetic Co 3 O 4 @CoO/g-C 3 N 4 ternary hybrid possessing double Z-scheme mechanism has been designed and architected by wet-impregnation and subsequent controlled oxidation process . In the Co 3 O 4 @CoO/g-C 3 N 4 ternary hybrid system, g-C 3 N 4 ultrathin nanopieces uniformly dispersed on each nanopetal of peony flower cobalt oxides , which not only helps to enhance the light absorption efficiency and avoid the aggregation but also readily promote the separation of photo-induced charge. Benefiting from the special hierarchical architecture, large open space between nanopetals and the synergistic effect between cobalt oxides and g-C 3 N 4 , when employed as photocatalyst for reduction of nitrobenzene (NB) and degradation of tetracycline (TC), 3D Co 3 O 4 @CoO/g-C 3 N 4 exhibited superior redox reactivity. Notably, a double Z-scheme heterojunctions and well matched band structures could further facilitate effective charge transfer. Meanwhile, Co 3 O 4 @CoO/g-C 3 N 4 ternary hybrids also exhibited excellent magnetic separation property and super cycling stability after four cycles, which make it a promising candidate as a visible light photocatalyst for practical application.
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高影响因子
TALANTA
·
2019
·
IF 4.916
Jie Ma,Lei Bian,Lei Zhao,Xiaotong Feng,Lizhi Zhao,Zhaoyan Wang,Qiaosheng Pu
Low-cost and nontoxic fluorescent reagents are important for on-site analysis performed by non-professionals. In this work, a cheap and widely available food additive , caramel was used as an effective fluorescence reagent for the sensitive detection of 2,4,6-trinitrophenol (TNP), 2,4-dinitrophenol (DNP) and 4-nitrophenol (4-NP). Through a simple dialysis, fluorescent components of a commercial caramel were harvested with a yield as high as 60%. The structural characterization demonstrated that the fluorescent components were dehydrated oligomers of carbohydrates. Their fluorescence can be quenched by these nitrophenols . The quenching mechanism was speculated as inner filter effect. At pH 8, a linear range of 0.2–22 μM and a detection limit of 90 nM could be achieved for TNP. Based on the difference of their quenching efficiency at different pHs, TNP, DNP and 4-NP can be simultaneously determined by solving the linear equations obtained at pH 3, 5 and 8. Successful detection of these nitrophenols in the water and soil samples was performed with relative standard deviations of 1.1–5.9% and recoveries of 95–108% of spiked standards.
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高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2018
·Vol. 42
·期 4
·888-896
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IF 2.415
Tianfu Wei,Gongke Li,Zhuomin Zhang
Covalently cross-linked microporous polymers are a new class of highly cross-linked porous network materials with large surface area and potential superiority in sample pretreatment. In this work, a covalently cross-linked microporous polymer was well designed and synthesized by condensation of acylhydrazines in terephthalic dihydrazide with aldehyde groups in 1,3,5-benzenetricarboxaldehyde. The adsorption mechanism was explored and discussed based on π-π stacking interaction and steric effect. Then, a covalently cross-linked microporous polymer was employed as the adsorbent of online micro-solid-phase extraction coupled with high-performance liquid chromatography for the enrichment and analysis of trace pesticide residues in citrus fruits. The method was successfully applied to the online analysis of sugar orange and Huangdigan samples with the detection limits of 0.10–0.30 μg/kg. It was satisfactory that chlorpifos and triazophos in real sugar orange and Huangdigan samples could be actually found and quantified at concentrations of 0.20 and 0.51 mg/kg, respectively. The recoveries of sugar orange and Huangdigan samples were in the range of 70.0–103 and 74.0–119% with relative standard deviations of 0.4–9.7 and 0.5–9.2% ( n = 3), respectively. The proposed method was accurate, reliable, and convenient for the online simultaneous analysis of trace pesticide residues in citrus fruits.
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高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 17
·4732-4747
·
IF 9.405
Shenghui Zhou,Fanglin Dai,Chao Dang,Ming Wang,Detao Liu,Fachuang Lu,Haisong Qi
Exploring both high-performance catalytic materials from non-edible lignocellulosic biomass and selective hydrodeoxygenation of bioderived molecules will enable value-added utilization of renewable feedstocks to replace rapidly diminishing fossil resources. Herein, we developed a scale-up and sustainable method to fabricate gram-quantities of highly dispersed cobalt nanocatalysts sheathed in multilayered N-doped graphene (Co@NG) by using a biomacromolecule carboxymethyl cellulose (CMC) as a raw material. The ionic gelation of CMC, urea and Co2+ ions leads to uniform dispersion and chelation of different species, consequently resulting in the formation of highly distributed Co nanoparticles (NPs) (10.91 nm) with N-enriched graphene shells in the solid-state thermolysis process. The usage of urea as a non-corrosive activation agent can introduce a porous belt-like nanostructure and abundant doped nitrogen. Among all the prepared catalysts in this work, the optimized Co@NG-6 with the largest specific surface area (627 m2 g−1), the most and strongest basic sites, and the highest proportion of pyridinic-N (37.6%) and mesopores exhibited excellent catalytic activity (99% yield of 2-methoxy-p-cresol) for base-free transfer hydrodeoxygenation (THD) of vanillin using bioderived formic acid (FA) as a H source at 160 °C for 6 h. The poisoning tests and electron paramagnetic resonance (EPR) spectra verified that the strong interaction between N atoms and encapsulated Co NPs provided synergistic effects, which were essential for the outstanding catalytic performance of Co@NG-6. The deuterium kinetic isotope effect study clearly demonstrated that the formation of Co-H−via β-hydride elimination and protonation was the rate-determining step, and protic N–H+ and hydridic Co-H− were considered to be active intermediate species in the THD reaction. Furthermore, Co@NG-6 was highly stable for recycling owing to the graphene shells preventing Co NPs from corrosion and aggregation.
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高影响因子
RSC Advances
·
2019
·Vol. 9
·期 41
·23560-23569
·
IF 3.049
Jian Liu,Rong Chen,Xun Zhu,Qiang Liao,Dingding Ye,Biao Zhang,Ming Liu,Gang Chen,Kun Wang
In this study, we proposed a Pd–polyelectrolyte multilayer (PEM) hybrid film grafted on the polydopamine coated interior wall of a microreactor for nitrobenzene hydrogenation. Here, Pd nanoparticles were in situ synthesized in the PEMs consisting of poly(diallyldimethylammonium chloride) and poly(styrene sulfonate) via a two-stage ion-exchange and reduction process. The preparation process was monitored by UV-vis spectroscopy, which confirmed the formation of Pd in the PEM film. In addition, SEM and ICP-OES results indicated that the Pd content in the PEM film could be controlled by the number of the ion exchange and reduction cycles. Experimental results also showed that the prepared Pd–PEM hybrid film was active for the hydrogenation of nitrobenzene. The microreactor with the Pd–PEM hybrid film via multiple times had the increased catalyst loading, leading to a high yield of aniline and much better durability. In addition, it was also found that the NaCl concentration in the polyelectrolyte solution could affect the structure of the PEM film and therefore the Pd loading and catalytic performance.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xinfeng Chen,Congming Sun,Yang Liu,Long Yu,Kui Zhang,Abdullah M. Asiri,Hadi M. Marwani,Hua Tan,Yuejie Ai,Xiangke Wang,Suhua Wang
As a new family of fluorescent materials, all inorganic perovskite quantum dots (PQDs) CsPbX 3 (Cl, Br, I) have attracted rising attention due to their intrinsic optical superiorities and potential applications in various fields. This work takes advantage of the bright fluorescence of PQDs and the strong electrophilic properties of picric acid (PA) to construct an analytical method for sensitive and selective discrimination of PA against other nitroaromatic explosives, and the limit of detection is as low as 0.8 nM. The quenching mechanism was elucidated as the formation of electrostatic complex and the electron transfer between PA and PQDs. To facilitate visual and on-site detection, the CsPbBr 3 PQDs were printed onto microfiltration membrane by inkjet printing to fabricate test papers for rapid and on-site detections of explosive and pollutant PA, showing a great research prospect in the detection of ultratrace PA at different sites.
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高影响因子
RSC Advances
·
2019
·Vol. 9
·期 32
·18098-18105
·
IF 3.049
Lamaocao Ma,Hengchang Ma
In this study, we report the synthesis of π-conjugated network polymers via palladium-catalyzed direct arylation polycondensation of triphenylamine (TPA) and tetraphenylethylene (TPE) with different active substrates. Moreover, six conjugated porous polymers were obtained (named as TPA-TPA-MA, TPA-PB-MA, TPA-TFB-MA, TPA-TPE-MA, TPE-PB-MA, and TPE-TFB-MA). Then, the fluorescence properties in the solid and dispersed states, the corresponding microporous structures, and the Brunauer–Emmett–Teller (BET) surface areas of all polymers were well studied. Among the obtained materials, TPA-PB-MA possessed not only largest BET surface area (686 m2 g−1) and largest pore volume (0.716 cm3 g−1), but also the smallest pore size of 0.823 nm. These properties are very beneficial for the application of TPA-PB-MA in CO2 storage and PA sensing. At 1 bar, TPA-PB-MA demonstrated the significant CO2 uptake of 2.70 and 1.35 mmol g−1 at 273 and 298 K, respectively. Furthermore, TPA-PB-MA was most sensitive and selective towards PA recognition. The KSV constant was measured as 4.0 × 104 M−1.
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高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
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2019
·
IF 4.346
Hao Feng,Xun Zhu,Rong Chen,Qiang Liao
In this work, the gas consumption characteristics were investigated by gas-liquid two-phase flow in a capillary microreactor using the catalytic hydrogenation of nitrobenzene as a reference gas-liquid reaction. Image processing technique was used to measure the gas consumption from the variation in the gas phase through the recorded images. The influence of the inlet nitrobenzene concentration and both the gas and liquid flow rates on the gas consumption and the microreactor performance was investigated. The experimental results showed that there existed a discrete hydrogen consumption process, i.e. the waiting stage and inburst stage. Hydrogen consumption was mainly attributed to the waiting stage in each bubble formation cycle. Minimal hydrogen was consumed in the inburst stage. In addition, there was a clear difference between the H 2 consumption rates under each operating condition. As the gas flow rate and nitrobenzene concentration increased, the H 2 consumption rate was gradually decreased with each successive formation cycle. Although the consumption rate was gradually reduced with each successive formation cycle with increasing liquid flow rate, the downward trend became increasingly gradual and clearly stabilized at 20 μL/min. The microreactor performances under different operating conditions were also investigated. The results showed that the nitrobenzene conversion was first increased and then gradually decreased with increasing the gas flow rate, whereas it was gradually decreased with increasing both the liquid flow rate and nitrobenzene concentration. The results obtained in this work are beneficial for not only understanding process intensification but also promoting the use of microreactor technology in additional industrial applications.
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高影响因子
Nanoscale
·
2019
·Vol. 11
·期 21
·10429-10438
·
IF 6.97
Yang Liu,Yapei Zhang,Xiaomin Li,Xuefeng Gao,Xiaoyan Niu,Wei Wang,Qiang Wu,Zhi Yuan
Fluorescent dyes, as a key factor in fluorescence imaging, usually exhibit a low signal-to-noise ratio (SNR) due to the limited loading capacities of delivery systems (usually less than 10.0 wt%) and their uncontrolled release. Herein, we developed a type of pH-responsive nanoplatform (MnO2/ZnCOF@Au&BSA) based on a zinc porphyrin covalent organic framework (COF), in which the zinc porphyrin (ZnPor) loading rate is 22.5 wt%. At pH = 7.4, the interlinked ZnPor in the assembly state did not show a fluorescence signal (“off” state). Together with the pH-triggered disintegration of ZnCOF in tumor cells (pH = 5.5), the scattered ZnPor displayed an obvious fluorescence signal recovery (“on” state). Simultaneously, the shed BSA-coated gold nanoparticles ingeniously caused the fluorescence signal to be further amplified through the metal-enhanced fluorescence effect, which was about 3.0-fold higher in vivo than in the free ZnPor group. Combined with the excellent photothermal therapy effect by the nanoplatform itself with the tumor inhibition rate of 79.5%, this nanosystem effectively solves the problem of low loading capacities and imaging SNR by traditional delivery systems, and successfully develops the potential of COFs for fluorescence imaging, achieving the purpose of integration of diagnosis and treatment.
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高影响因子
JOURNAL OF LUMINESCENCE
·
2018
·
IF 2.732
YaoYao Qu,Guojuan Ren,Liying Yu,Baoya Zhu,Fang Chai,Lihua Chen
Herein, the fluorescent carbon dots (CDs) has been synthesized by hydrothermal method by using ethylene diamine tetraacetic acid (EDTA) as a raw materials. The prepared CDs exhibited bright blue fluorscence excited by 340 nm with the quantum yield as high as 52%. The CDs possess special fluorescence responses to 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), and the slump of fluorescence was demonstrated by CDs solution in the case of 2-nitrophenol and 4-nitrophenol existence. The detection limit of 2-NP and 4-NP was calculated at 77 nM and 60 nM, respectively. Meanwhile, the color response to 2-NP and 4-NP can be observed from achromatic solution to yellow by naked eye. All in all, the obtained CDs can be applied as fluorescence and colorimetric probe in environmental protection.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Ze-Chen Gao,Yi-Li Lin,Bin Xu,Ying Xia,Chen-Yan Hu,Tong-Cheng Cao,Xiang-Yun Zou,Nai-Yun Gao
This study revealed the iopamidol degradation performance and the synergistic effect of dual-wavelength ultraviolet light-emitting diodes (UV-LEDs). It was found that the dual-wavelength irradiation (265 and 280 nm) can promote iopamidol degradation during both UV-LED alone and UV-LED/chlorine processes ( p < 0.05). The effects of key experimental parameters including pH, chlorine dosage and water matrix during UV-LED/chlorine process were evaluated. Peak degradation rate was observed at pH 7.0 due to the combined effects of the quantum yield of aquatic chlorine photolysis (Φ chlorine ) and absorptivity of chlorine. The destruction pathways of iopamidol in the UV-LED/chlorine process were proposed by Ultra Performance Liquid Chromatography-Electrospray Ionization-mass spectrometry. Additionally, an opposite trend of iodinated trihalomethane (I-THM) formation during subsequent chlorination between Milli-Q and real waters with prolonging irradiation time was observed, while other detected disinfection by-product (DBP) formation showed the same variation in Milli-Q and real waters. The UV-LED/chlorine treatment using dual-wavelength can enhance iopamidol degradation significantly, but it also promoted I-THM formation in real water, indicating the need for evaluating DBPs before the application of UV-LED/chlorine process in drinking water treatment.
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高影响因子
Nanoscale
·
2018
·Vol. 11
·期 3
·1286-1294
·
IF 7.233
Yulian Li,Lingyun Feng,Wei Yan,Irshad Hussain,Li Su,Bien Tan
Copper nanoclusters (CuNCs) exhibit susceptibility to oxidation in the subnanometer size range. In this work, a facile and green protocol is reported for the successful synthesis of water soluble CuNCs, with poly(vinylpyrrolidone) as a template and ascorbic acid as a mild reducing agent. The as-prepared CuNCs exhibit a green fluorescence and high quantum yield (QY = 44.67%) in water, which is the highest among the reported water soluble CuNCs. The origin of their highly luminescent nature was also investigated. In addition, the obtained CuNCs show good tolerability to high ionic strength, superior antioxidation properties, good photostability, time-stability, a large Stokes shift and ultralow cytotoxicity, laying the foundation for living cell imaging in THP-1 macrophages. A bright green fluorescence can be observed from the cells, indicating the potential practicality of CuNCs as a fluorescence marker in bioapplications. Interestingly, the as-prepared CuNCs exhibit a good selective fluorescence quenching response towards trinitrophenol over other nitro compounds. Furthermore, CuNCs were employed for sensing trinitrophenol based on the inner filter effect. A good linear relationship was obtained in the low concentration range of trinitrophenol, with a limit of detection of 3.91 × 10−7 M in aqueous medium. This result suggests the potential application of CuNCs as a probe in sensing and monitoring toxic trinitrophenol in the field of environmental security.
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高影响因子
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