Small
·
2018
·Vol. 14
·期 48
·1803015
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IF 9.598
Ning Zhang,Baopeng Yang,Yuanqing He,Yulu He,Xiaohe Liu,Min Liu,Guoyong Song,Gen Chen,Anqiang Pan,Shuquan Liang,Renzhi Ma,Shishir Venkatesh,Vellaisamy A. L. Roy
Layered serpentine Ni 3 Ge 2 O 5 (OH) 4 is compositionally active and structurally favorable for adsorption and diffusion of reactants in oxygen evolution reactions (OER). However, one of the major problems for these materials is limited active sites and low efficiency for OER. In this regard, a new catalyst consisting of layered serpentine Ni 3 Ge 2 O 5 (OH) 4 nanosheets is introduced via a controlled one-step synthetic process where the morphology, size, and layers are well tailored. The theoretical calculations indicate that decreased layers and increased exposure of (100) facets in serpentine Ni 3 Ge 2 O 5 (OH) 4 lead to much lower Gibbs free energy in adsorption of reactive intermediates. Experimentally, it is found that the reduction in number of layers with minimized particle size exhibits plenty of highly surface-active sites of (100) facets and demonstrates a much enhanced performance in OER than the corresponding multilayered nanosheets. Such a strategy of tailoring active sites of serpentine Ni 3 Ge 2 O 5 (OH) 4 nanosheets offers an effective method to design highly efficient electrocatalysts.
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Chemistry-An Asian Journal
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2018
·Vol. 14
·期 1
·235-242
·
IF 3.692
Weitao Xu,Jinglan Kan,Bo Yang,Timothy J. Prior,Bing Bian,Xin Xiao,Zhu Tao,Carl Redshaw
Graphical Can I have some pumpkin soup, please? In the host–guest complexes formed between cucurbit[8]uril and the alkyl-substituted 4-pyrrolidinopyridinium salts 4-(C 4 H 8 N)C 5 H 5 NRBr (R=Et, n -butyl, n -pentyl, n -dodecyl), the orientation of the guest molecule changes with the length of R. Solid state structures are different to those observed in solution, and for R= n -pentyl, there are two different interactions between Q[8] and the guest. The interaction between cucuribit[8]uril (Q[8]) and a series of 4-pyrrolidinopyridinium salts bearing aliphatic substituents at the pyridinium nitrogen, namely 4-(C 4 H 8 N)C 5 H 5 NRBr, where R=Et (g1), n -butyl (g2), n -pentyl (g3), n -hexyl (g4), n -octyl (g5), n -dodecyl (g6), has been studied in aqueous solution by 1 H NMR spectroscopy, electronic absorption spectroscopy, isothermal titration calorimetry and mass spectrometry. Single crystal X-ray diffraction revealed the structure of the host–guest complexes for g1, g2, g3, and g5. In each case, the Q[8] contains two guest molecules in a centrosymmetric dimer. The orientation of the guest molecule changes as the alkyl chain increases in length. Interestingly, in the solid state, the inclusion complexes identified are different from those observed in solution, and furthermore, in the case of g3, Q[8] exhibits two different interactions with the guest. In solution, the length of the alkyl chain plays a significant role in determining the type of host–guest interaction present.
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JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2015
·
IF 3.564
Zhi-bo Zhang,Qiang Lu,Xiao-ning Ye,Wen-tao Li,Ying Zhang,Chang-qing Dong
A new technique was proposed to selectively produce 4-ethyl phenol (4-EP) from low-temperature catalytic fast pyrolysis of certain herbaceous biomass, while 4-vinyl phenol (4-VP) could be selectively produced from non-catalytic fast pyrolysis process. In this study, Pd/SBA-15 catalysts were prepared, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique was applied for both ex situ and in situ catalytic fast pyrolysis of bagasse . The results indicated the 4-EP could be selectively produced from both catalytic methods. During the ex situ catalytic pyrolysis process, the bagasse would decompose to form 4-VP which was then hydrogenated by the Pd/SBA-15 catalyst to be 4-EP. During the in situ catalytic pyrolysis process, the Pd/SBA-15 catalyst would catalyze the decomposition and hydrogenation of bagasse to directly produce 4-EP. Certain pyrolytic products would serve as the hydrogen-donors (H-donor) for the formation of 4-EP. The selectivity of the 4-EP from the ex situ catalytic process was a little better than that form the in situ catalytic process. The highest 4-EP yield from ex situ catalytic pyrolysis of bagasse was around 2.0 wt%, obtained at the pyrolysis temperature of 350 °C and catalyst-to-biomass ratio of 1.5.
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APPLIED SURFACE SCIENCE
·
2014
·
IF 2.538
Penghui Shao,Jiayu Tian,Zhiwei Zhao,Wenxin Shi,Shanshan Gao,Fuyi Cui
Visible light photocatalytic activity of amorphous TiO 2 doped with carbon is prepared by a facile sol-gel route for the first time. The most active sample with mesostructure of amorphous phase, high surface area (273 m 2 g −1 ) and large pore volume (0.33 cm 3 g −1 ) is identified by X-ray diffractometer, Raman spectrometer, transmission electron microscope and N 2 adsorption–desorption isotherms. In addition, the most active sample is characterized by Fourier transform-infrared spectrometer, X-ray photoelectron spectrometer, UV–vis diffuse reflectance spectrometer and luminescence spectrometer. The results show that the most active sample with oxygenic groups has a narrower bandgap and lower recombination of electron–hole, due to the carbon doping and phase of amorphous. Effective photodegradation capability and stability of rhodamine B and colorless 4-chlorophenol are verified by photocatalytic tests under visible light irradiation. A possible mechanism of amorphous TiO 2 doped with carbon for visible light photocatalysis is proposed. The findings of this paper will provide new insights to design visible light-induced photocatalyst based on amorphous TiO 2 for organic removal.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2014
·Vol. 73
·期 2
·299-305
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IF 1.547
Wang Zhen-Zhen,Zhai Shang-Ru,Zhang Feng,Xiao Zuo-Yi,Zhai Bin,An Qing-Da
This work presented a novel, facile, cost-effective and environmentally friendly approach for the preparation of magnetic core–shell structured catalyst i.e. Fe 3 O 4 @SN–Ag (abbreviation of Fe 3 O 4 @SiO 2 –NH 2 –Ag). During the process of preparation, Ag nanoparticles were in situ generated with amino groups in the surface of Fe 3 O 4 @SN serving as green reductant and stabilizer in the absence of any additional toxic reductant or organic reagent. Magnetic core, Fe 3 O 4 , was easily prepared through solvothermal method. The subsequent coating and surface amino functionalization of SiO 2 was accomplished via one-pot sol–gel method, which was green and time-saving. What’s more, the resulting catalyst exhibited excellent catalytic property (the reaction was finished within 2 min) and reusability (reused at least seven times) in the reduction of 4-nitrophenol.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2014
·
IF 2.045
Guo-Min Yu,Li-Sheng Wang,Chao-Jun Du
A phosphorus flame retardant of 4-(hydroxymethyl)-1-oxido-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane (PEPA) was synthesized by pentaerythritol and phosphorus oxychloride at a certain condition. The structural features of PEPA were investigated with Fourier transform infrared spectroscopy and 1H NMR methods. The thermal behavior of PEPA was carried out with differential scanning calorimetry and thermogravimetric analysis instruments. A static analytic method was used to measure the solubilities of the PEPA in several organic solvents. The measurements were accurately acted in ethyl acetate, acetonitrile, isopropyl alcohol, ethanol, n-propyl alcohol, acetone, methanol, and chloroform at the temperature range from 292.75 K to 333.45 K. Using the Scatchard–Hildebrand methodology, the activity coefficients of the solute have been calculated, and the partial molar excess enthalpies at infinite dilution were also predicted.
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TALANTA
·
2015
·
IF 3.545
Ganghui Chu,Wensheng Cai,Xueguang Shao
Ring-opening reaction with synchronous hydrolysis was used to prepare 4-butylaniline-modified attapulgite (abbreviated as BA-ATP) for pre-concentration of bisphenol A (BPA) in trace quantity. The preparation was achieved under mild condition, and the material was characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis , nuclear magnetic resonance (NMR) and scanning electron microscopy. BA-ATP was used in solid phase extraction (SPE), and SPE was performed in a neutral condition without regard to ionic strength . The results indicate that BA-ATP has high affinity to BPA with a maximum adsorption amount of 44 mg g −1 , and the adsorption can be described by Langmuir isotherm model. The content of bisphenol A in water samples was analyzed by HPLC method with the pre-concentration using BA-ATP. The limit of detection (LOD) can be as low as 3.9 ng mL −1 , and the average recoveries are in a range of 93–97% with relative standard deviation (RSD) of less than 2%.
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APPLIED SURFACE SCIENCE
·
2013
·
IF 2.112
Man Wang,Di Tian,Panpan Tian,Liangjie Yuan
Ag nanoparticles (Ag NPs) were deposited on the surface of micron silica spheres. The structure of the composite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscope (TEM) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) method. The as-prepared micron-SiO 2 @nano-Ag particles were used as a catalyst in the borohydride reduction reaction of 4-nitrophenol (4-NP), which was detected by UV–vis absorption spectroscopy. The result showed that the composite particles presented a comparable catalytic activity with that of spherical silver nanoparticles.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2013
·
IF 5.257
Zhihui Ai,Zhiting Gao,Lizhi Zhang,Weiwei He,Jun Jie Yin
In this study, core–shell Fe@Fe2O3 nanowires with different iron oxide shell thickness were synthesized through tuning water-aging time after the reduction of ferric ions with sodium borohydride without any stirring. We found that these Fe@Fe2O3 nanowires exhibited interesting core–shell structure dependent reactivity on the aerobic degradation of 4-chlorophenol. Characterization results revealed that the core–shell structure dependent aerobic oxidative reactivity of Fe@Fe2O3 nanowires was arisen from the combined effects of incrassated iron oxide shell and more surface bound ferrous ions on amorphous iron oxide shell formed during the water-aging process. The incrassated iron oxide shell would gradually block the outward electron transfer from iron core for the subsequent two-electron molecular oxygen activation, but more surface bound ferrous ions on iron oxide shell with prolonging aging time could favor the single-electron molecular oxygen activation, which was confirmed by electron spin resonance spectroscopy with spin trap technique. The mineralization of 4-chlorophenol was monitored by total organic carbon measurement and the oxidative degradation intermediates were analyzed by gas chromatography–mass spectrometry. This study provides new physical insight on the molecular oxygen activation mechanism of nanoscale zerovalent iron and its application on aerobic pollutant removal.
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Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 31
·8066-8073
·
IF 4.696
Shunyu Jin,Yan Tian,Fei Liu,Jun Chen,Shaozhi Deng,Ningsheng Xu
Although 9,10-bis(4-(1,2,2-triphenylvinyl)styryl)anthracene (TPE-An) with excellent aggregation-induced emission (AIE) properties can effectively enhance the luminescence efficiency of light-emitting materials, the practical TPE-An-emitting electroluminescent (EL) devices have not been successfully fabricated until now. In our paper, the energy-band diagram of TPE-An is determined by the combination of ultraviolet-visible (UV-Vis) spectroscopy and cyclic voltammetry (CV) techniques. Subsequently, the space-charge-limited-current (SCLC) method is firstly used to obtain the hole mobility of TPE-An and design a better EL device structure. By calculation, the maximum hole mobility of the 50 nm TPE-An film can arrive at 4.00 × 10−4 cm2 V−1 s−1 at 0.1 MV cm−1 field. Finally, TPE-An-emitting EL devices have been, respectively, fabricated on glass and flexible PET substrates. Both of these two EL devices exhibit an intense green-light emission at 515 nm. Moreover, the maximum luminance of the EL device on glass can reach 24721.8 cd m−2 at 10.0 V, and its maximum current efficiency is as high as 14.7 cd A−1 at 131.6 mA cm−2. It is noted that the flexible EL device on the PET substrate maintains a stable emission and nice working performance even if the bending angles arrive at 140°. Therefore, it suggests that TPE-An should have a promising future in EL device applications.
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BIODEGRADATION
·
2016
·Vol. 27
·期 1
·37-46
·
IF 2.208
Zhou YuYang,Huang Huanlin,Shen Dongsheng
This study evaluated substrate interactions during the aerobic biodegradation of 1, 4-dioxane and BTEX mixtures by a pure culture, Acinetobacter baumannii DD1, which is capable of utilizing 1, 4-dioxane for growth. A. baumannii DD1 could utilize BTEX as a sole carbon source, but could not utilize m -xylene and p -xylene. In binary mixtures, there was a lag of about 14 h before the degradation of BTE, and 1, 4-dioxane only started to be utilized when BTE was completely degraded by 1, 4-dioxane-grown DD1. Furthermore, the biodegradation rate of 1, 4-dioxane decreased from 73.33 to 40.74 mg/(h g dry weight) after the biodegradation of benzene. 1, 4-dioxane could not be degraded after the biodegradation of o -xylene in 80 h. DD1 could also not degrade m -xylene and p -xylene coexisting with 1, 4-dioxane. The ability of DD1 to degrade BTEX occurred in the following order: benzene > ethylbenzene > toluene > o -xylene > m -xylene = p -xylene. The biodegradation of 1, 4-dioxane was not activated in the mixture with o -xylene, primarily because of the accumulation of the specific toxic intermediate, 2, 3-dimethylphenol. The lag in BTE degradation was presumably because of the induction of enzymes necessary for BTE degradation. Additionally, SDS-PAGE analysis demonstrated that there were different proteins during the degradation of benzene and 1, 4-dioxane.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2014
·
IF 6.007
Qi Huang,Menghua Cao,Zhihui Ai,Lizhi Zhang
In this study, an environmentally benign polyaminocarboxylic ligand diethylenetriamine pentacetate (DTPA) was first used to promote the aerobic 4-chlorophenol (4-CP) degradation with Fe@Fe 2 O 3 core–shell nanowires, and then compared with the most used counterpart ethylenediamine tetraacetate (EDTA) of poor biodegradability. Although the 4-CP removal rate in the Fe@Fe 2 O 3 /DTPA/Air system was slower owing to the preferential degradation of DTPA, the total organic carbon removal rate in the Fe@Fe 2 O 3 /DTPA/4-CP/Air system was much faster than that in the Fe@Fe 2 O 3 /EDTA/4-CP/Air system. We interestingly found that hydroxyl radicals could more easily react with DTPA to produce DTPA radicals than with EDTA to produce EDTA radicals. Ligands (DTPA or EDTA) could significantly accelerate the hydroxyl radicals production with Fe@Fe 2 O 3 , while more hydroxyl radicals were generated in the Fe@Fe 2 O 3 /DTPA/Air system. We also employed gas chromatography-mass spectrometry and ion chromatography to detect organic intermediates and chloride ions to probe the 4-chlorophenol degradation pathways, and found its degradation pathways were dependent on the reactive oxygen species generated in the different systems. This study can clarify the roles of polyaminocarboxylic ligands on the molecular oxygen activation with nanoscale zero-valent iron, and also provide a green chlorophenols removal method.
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