CRYSTENGCOMM
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2017
·Vol. 19
·期 17
·2288-2293
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IF 3.474
Jinpeng Lv,Yuan Liu
Clarifying the origin of green photoluminescence and the room temperature ferromagnetism in ZnO is crucial for its potential application. In this work, we show that the characteristic 368 nm donor-bound exciton and the g = 1.96 electron spin resonance (ESR) signal in ZnO nanocrystals were eliminated after H2O2 oxidation, along with the appearance of 550 nm photoluminescence, unambiguously evidencing the creation of acceptor defects. Meanwhile, the d0 ferromagnetism was significantly enhanced. In combination with the fact that ambient O2 exposure also resulted in a significant boost of ferromagnetism in ZnO particles with different grain sizes, we surmise that adsorbed oxygen facilitates the d0 ferromagnetism in ZnO while VZn causes the 550 nm green emission. This work illustrates that oxygen exposure is an efficient way to tune the physics in metal oxides through engineering defects.
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SENSORS AND ACTUATORS B-CHEMICAL
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2016
·
IF 4.758
Shuo Geng,Shu Min Lin,Shi Gang Liu,Wei Zhang,Nian Bing Li,Hong Qun Luo
We synthesized polyethyleneimine capped ZnO quantum dots (PEI-ZnO QDs) which dispersed well in ethanol by using a two-step method. UV–visible absorption spectroscopy, photoluminescence, Fourier transform infrared spectroscopy, high resolution transmission electron microscope, and field emission scanning electron microscope were used to characterize the as-prepared PEI-ZnO QDs. It emitted green-yellow fluorescence (527 nm) for excitation at 355 nm. We used the PEI-ZnO QDs to determine the alcoholic strength because of its different property in water and ethanol which caused decrease in the PEI-ZnO QDs fluorescence intensity with increasing water content. With this method, we determined the alcoholic strength of different artificial samples with a linear range from 20% to 60% vol and detected commercial spirits with satisfactory results.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2016
·Vol. 28
·期 1
·958-962
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IF 1.798
Wang Han,Li Haiying,Li Shouchun,Liu Li,Wang Lianyuan,Guo Xuexin
Biomorphic In 2 O 3 –ZnO hollow microtubules were synthesized by using cotton as template and followed by calcination. This environmental-friendly method using biomaterials as templates can be used to synthesize metal oxide semiconductor materials with specific morphologies. The structural and microscopy characterization were carried out with X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy. The SEM images display the porous structure of the as-obtained hollow microtubules, which is beneficial to increase gas sensing properties of materials. Gas sensors based on In 2 O 3 -doped ZnO hollow microtubules were investigated and the test results demonstrate the excellent acetone sensing properties of such porous materials. The response of In 2 O 3 –ZnO hollow microtubule sensors to 100 ppm acetone at the optimum temperature of 300 °C is 62.5, meanwhile the response and recovery times are 3 and 7 s, respectively. Moreover, even at 0.1 ppm of acetone detectable response can be observed, and the value is 2.82. At the same time the sensors have selectivity to acetone.
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CHEMICAL PHYSICS LETTERS
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2016
·
IF 1.86
Zhenrong Jia,Ying Wei,Xiaofeng Wang,Siwei Hu,Kai Yao,Fan Li
Herein, the liquid crystal molecule, 3,6-bis(5-(4-hexyl-phenyl)-2-thienyl)-2,5-bis(2-ethylhexyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP-TP6), is introduced into P3HT/ZnO to control the morphology of the hybrid system. Induced by the self-assembly behavior of DPP-TP6 upon thermal treatment at the mesomorphase temperature, the dispersion of ZnO nanocrystals is effectively improved and the crystallinity and ordering of the P3HT is also enhanced, which provides more interfacial area for exciton dissociation and efficient path for carrier transport. On such basis, the power conversion efficiency of P3HT/ZnO hybrid solar cells is improved mainly due to the increase of J sc .
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JOURNAL OF ALLOYS AND COMPOUNDS
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2016
·
IF 3.014
Qian Feng,Dongyan Tang,Haitao Lv,Weile Zhang,Wenbo Li
We reported on the fabrication of thermo-responsive polymers of poly( N -isopropylacrylamide) (PNIPAM) graft ZnO by surface-initiated atom transfer radical polymerization (SI-ATRP) to contribute the characteristics of the grafted PNIPAM, meanwhile, without sacrificing the properties of ZnO. The structures of nanoparticles and the grafted polymer were confirmed by XRD and FT-IR and the interactions between the two components were studied by XPS . The morphology of ZnO NPs-PNIPAM nanocomposites was observed by SEM images and a thin layer of polymers (2 nm) formed around NPs was measured by TEM. EDS mapping images revealed the even distribution polymers on the surface of ZnO NPs. Based on the TG results, the grafting density of ATRP initiators at the surface of ZnO NPs was estimated to be 0.7 nm 2 /initiator. Furthermore, photodegradation of Rhodamine B (Rh-B) in the presence of nanocomposites revealed that ZnO NPs-PNIPAM exhibited photocatalysis , temperature-controlled switching and good recycling performance, indicating the significant potential applications in the practical applications.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2016
·
IF 3.014
Yonghai Song,Yaqin Chen,Jiafeng Wu,Yuanyuan Fu,Rihui Zhou,Shouhui Chen,Li Wang
In the contemporary era, energy demands are ever-growing and a significant number of people are concerned about environmental pollution caused by the burning of fossil fuels. Therefore, it is a striking problem for the researchers to pursue renewable energy and sustainable energy to deal with the environmental and energy crisis. In this work, a novel hybrid hollow porous ZnO/C nanocages with high specific surface areas of 256 m 2 g −1 and high carbon content in weight of about 50% used as anode materials for lithium ion batteries (LIBs) were synthesized by a one-step pyrolysis of hollow metal organic framework material MOF-5 as both precursor and self-sacrificing template under N 2 atmosphere. The hollow porous ZnO/C nanocages released an initial discharge capacity of 1928 mA h g −1 at the current density of 100 mA g −1 and remained a high reversible capacity of 750 mA h g −1 after 100 cycles. According to the results of electrochemical measurements, the hollow porous ZnO/C nanocages also showed a good rate capability of 351 mA h g −1 at a relative large current density of 2 A g −1 . The excellent electrochemical performance was mainly due to the special nanostructures of the fabricated materials. Hence, the as-resulted hollow porous ZnO/C nanocages are promising anode materials for LIBs.
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JOURNAL OF POROUS MATERIALS
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2016
·Vol. 24
·期 3
·613-620
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IF 1.385
Fu Yuanyuan,Zhong Baoying,Chen Yaqin,Song Yonggui,Zhou Rihui,Song Yonghai,Chen Shouhui
A novel porous spherical ZnO@carbon (C) nanocomposite based on zeolitic imidazolate frameworks (ZIFs-8)-directed method was prepared for lithium-ion batteries (LIBs). In this strategy, spherical ZnO nanoparticles were firstly prepared, then 2-methylimidazolate and Zn 2+ were added alternately under ultrasound to fabricate ZnO@ZIF-8. Finally, the novel porous spherical ZnO@C nanocomposites were obtained via pyrolyzing the corresponding ZnO@ZIF-8. The novel porous spherical ZnO@C nanocomposites were characterized with different analysis techniques such as scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction. The resulted spherical ZnO@C nanocomposites exhibited a high reversible capacity of 932 mA h g −1 at 0.1 A g −1 after 100 cycles, which is much higher than that of the pure ZnO nanoparticles. The porous structure, high specific surface area and good electrical conductivity eventually contribute to the good performance of the resulted ZnO@C nanocomposites for LIBs should be ascribed to the proous structure and high BET surface area derived from ZIFs, as well as the good electrical conductivity of the amourphous carbon derived from ZIFs.
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Materials Research Express
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2017
·Vol. 4
·期 2
·025605
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IF 1.068
Xiaoqing Dai
Nano ZnO enhanced 3D porous reduced graphene oxide (RGO) with superior electromagnetic interferece (EMI) shielding efficiency (SE) was fabricated through a UV enhanced hydrothermal process. In this study, a composite with 10 wt% of 3D-RGO/ZnO was tested in a broadband frequency range from 2 to 18 GHz. Under the whole test conditions, the ratio of SEA/SET is higher than 50% and the maximum value can reach to 94%, indicating the shielding mechanism mainly attributes to absorption. The EMI SE showed that the thinnest thicknesses to shield different frequency range are 0.7 mm for 10 dB, 1.6 mm for 20 dB and 3.7 mm for 30 dB, which suggests 3D-RGO/ZnO could meet the requirement of new generate EMI shielding material.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2016
·
IF 8.328
Qingzhi Luo,Xiaolian Yang,Xiaoxiao Zhao,Desong Wang,Rong Yin,Xueyan Li,Jing An
Well-dispersed zinc oxide/cyclized polyacrylonitrile (ZnO/CPAN) nanocomposites were prepared by a facile in-situ precipitation method. The mixture solution of dimethyl sulfoxide containing zinc nitrate and polyacrylonitrile (PAN) was added dropwise into ammonia water under vigorous magnetic stirring. Accompanied by the precipitation of PAN in water, zinc hydroxide were simultaneously formed via in-situ reaction of zinc nitrate with hydroxyl ions, leading to the uniform dispersion of zinc hydroxide nanoparticles in the precursor of ZnO/PAN nanocomposites. Then ZnO/CPAN nanocomposites were prepared by calcining the obtained precursor at 250 °C in nitrogen atmosphere via cyclization/dehydrogenation reaction of PAN and decomposition reaction of Zn(OH) 2 . The as-prepared ZnO/CPAN nanocomposites were characterized by XRD, SEM, XPS, UV–vis DRS, PL, etc. Results show that CPAN molecules in ZnO/CPAN nanocomposites significantly decrease the mean size of ZnO nanocrystals, increase the quantity of oxygen defects in ZnO particles, improve the absorbance of ZnO in the whole wavelength range especially in the visible-light range, and obviously reduce the recombination probability of photo-generated electron/hole pairs. The photocatalytic activity of ZnO/CPAN nanocomposites was evaluated by photodegradation of methyl orange (MO) solution under visible light irradiation. Experiment results reveal that the apparent rate constant k of MO photodegradation under visible light irradiation photocatalyzed by ZnO/CPAN (0.361 h −1 ) is 1.28, 5.84 and 25.8 times of that by AgBr (0.282 h −1 ), Ag 3 PO 4 (0.0618 h −1 ) or g–C 3 N 4 (0.0140 h −1 ), respectively, meaning that ZnO/CPAN exhibits much higher visible-light photocatalytic activity than these typical visible-light photocatalysts. The visible-light photocatalytic mechanism has been discussed.
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Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 7
·1685-1691
·
IF 5.256
Rui Zhou,Qi Zhao,Kai-Kai Liu,Ying-Jie Lu,Lin Dong,Chong-Xin Shan
A hybrid nanostructure based on ZnO quantum dots (QDs) has been fabricated for ratiometric detection of Bacillus anthracis spores, where yellow-emitting ZnO QDs are employed as the internal reference and europium ions (Eu3+) are chelated on the surface of the ZnO QDs as the signal report unit. The Eu3+ exhibits enhanced red luminescence upon bonding with calcium dipicolinate (CaDPA), an important biomarker of Bacillus anthracis spores, while the fluorescence of the ZnO QDs will not be altered. Accordingly, increased CaDPA levels can lead to variation of the two fluorescence intensity ratios of the ZnO/Eu hybrid nanostructure. The time-dependent fluorescence response reveals that the reaction can be completed within 8 s, thus enabling the rapid detection of Bacillus anthracis spores. The detection limit for CaDPA is 3 nM, which is six orders of magnitude lower than an infectious dosage of Bacillus anthracis spores for human beings (60 μM). In addition, the sensor shows a remarkable selectivity for CaDPA over other aromatic ligands, amino acids and common cellular ions. The fast response speed as well as good sensitivity and selectivity means the ZnO/Eu nanostructure has great potential applications in clinical analysis.
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JOURNAL OF NANOPARTICLE RESEARCH
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2017
·Vol. 19
·期 10
·1-12
·
IF 2.02
Tian Fei,Niu Libo,Chen Bo,Gao Xuejia,Lan Xingwang,Huo Li,Bai Guoyi
A novel magnetic core-shell nanocomposite Fe 3 O 4 @Chitosan@ZnO was successfully prepared by in situ chemical precipitation method. It has a clear core-shell structure with magnetic Fe 3 O 4 (about 160 nm in diameter) as core, chitosan as the inner shell, and ZnO as the outer shell, as demonstrated by the transmission electron microscopy and the related elemental mapping. Moreover, this nanocomposite has high magnetization (43.6 emu g −1 ) so that it can be easily separated from the reaction mixture within 4 s by an external magnetic field. The introduction of the natural chitosan shell, instead of the conventional SiO 2 shell, and its combination with the active ZnO ensures this novel nanocomposite green character and good catalytic performance in the synthesis of 2-benzimidazoles with moderate to excellent isolated yields at room temperature. Notably, it can be recycled seven times without appreciable loss of its initial catalytic activity, demonstrating its good stability and making it an attractive candidate for the green synthesis of 2-benzimidazoles.
A novel magnetic core-shell nanocomposite exhibited high activity and good stability in the green synthesis of 2-benzimidazoles under mild reaction conditions.
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JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yuting Liu,Yinyu Chen,Huiying Ding,Jingchuan Xue,Yang Yang,Xianhui Li
Achieving the removal of pharmaceuticals and personal care products (PPCPs) while selectively rejecting divalent cations like Ca 2 ⁺ and Mg 2 ⁺ without compromising water productivity and recovery remains a challenge for existing commercial nanofiltration (NF) membranes used in drinking water treatment. These challenges stem from the limited pore size and insufficient negatively charged surface density of conventional NF membrane. This study employed a polydopamine-coated nanofibrous membrane, uniformly embedded with in-situ grown ZnO nanoparticles, as a porous support layer. In the interfacial polymerization process, the fabricated substrate regulated the diffusion of aqueous monomers, thereby optimizing the polyamide layer on composite NF membrane with thinner thickness, stronger surface density, crumple structure and appropriate pore size. This resulting membrane demonstrated excellent PPCP rejection while maintaining high permeability to essential minerals. Under optimal conditions, the designed membrane achieved an impressive water flux at about 21 L m⁻ 2 h⁻ 1 bar⁻ 1 and showed significant selectivity for PPCP and divalent cation, with diclofenac sodium rejection exceeding 90 % and Ca 2 ⁺ rejection of below 20 %. The incorporation of ZnO nanoparticles enlarged the active filtration surface and created additional water pathways, resulting in a water permeation rate that was double that of a pristine NF membrane, without compromising PPCP/divalent cation selectivity. This work provides valuable insights and important correlations for developing NF membranes aimed at enhancing water production while preserving selectivity for PPCP/divalent cation.
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危险品化学品经营许可证（带存储）