JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 131
·期 19
·
IF 1.64
Weiwei Cai,Hui Yang,Daxin Han,Xingzhong Guo
Porous ethyl cellulose (EC) microspheres were prepared via a physical method in oil-in-water (O/W) emulsions. The morphologies and pore structures of the resulting porous microspheres were investigated by scanning electron microscopy (SEM), mercury porosimeter and spectrometer equipped with an integrating sphere. The increase of EC amount in oil phase will increase the size of the microspheres. All the microspheres possess open macropores in the shell and interconnected pores inside the microspheres by means of phase separation. The saturation of the Ethyl acetate (EA) in external phase has an effect on the morphology of the EC particles obtained. Using EA unsaturated aqueous solution as the external water phase in the emulsion process results in the formation of porous EC particles with irregular shape. The loaded TiO 2 nanoparticles uniformly disperse in EC matrix, and slightly deceases the size and volume of interconnected pores inside the microspheres. The addition of TiO 2 nanoparticles is also proved to increase the light-scattering power of the porous EC microspheres. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40822.
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CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2013
·Vol. 92
·期 5
·851-860
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IF 1.003
Zhenhua Pan,Qizhou Cai,Qiang Luo,Xinwei Li
The mechanism and kinetics of synergetic effect in TiO 2 /O 3 /UV process on H-acid degradation were investigated. The experimental results showed that H-acid removal rate of TiO 2 /O 3 /UV process was the highest among TiO 2 /UV, O 3 /UV and TiO 2 /O 3 /UV processes. The investigation of reactions with suitable active species scavengers confirmed that H-acid was mainly oxidised by ozone and holes on TiO 2 in the TiO 2 /O 3 /UV process. The recombination between holes and electrons in TiO 2 reduced in the presence of ozone, as indicated by fluorescence emission spectra. Moreover, the intermediates generated during H-acid oxidation in various processes were analysed by LC/MSD trap. It is proposed that H-acid was oxidised to polyhydroxy aromatics, benzene carboxylic acids and quinoids in the first step. Then, saturated aliphatics carboxylic acids were formed and mineralised to inorganic compounds through the Photo-Kolbe reaction. Finally, a kinetic study on TiO 2 /UV, O 3 /UV and TiO 2 /O 3 /UV processes was conducted and it was confirmed that both ozonation and photocatalytic activity were improved in TiO 2 /O 3 /UV process because of the synergetic effect.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Zhongshan Ren,Xiaojun Hu,Xiangxin Xue,Kuochih Chou
The solid state reactions in Fe 3 O 4 –TiO 2 system has been studied by diffusion couple experiments at 1323–1473 K, in which the oxygen partial pressure was controlled by the CO–CO 2 gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-diffusion coefficients in Fe 3 O 4 phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of diffusion layer and temperature, the diffusion coefficient of the Fe 3 O 4 –TiO 2 system was obtained. According to the Arrhenius equation, the estimated diffusion activation energy was about 282.1 ± 18.8 kJ mol −1 .
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SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Xiaogan Li
Pure mesoporous TiO 2 microspheres based chemoresistive gas sensors showed response to several organic volatile compounds (VOCs) such as formaldehyde, methanol, ethanol, ammonia and acetone under the UV illumination in the humid air at room temperature . With the loading of NiO at the porous surface of TiO 2 microspheres, the sensor indicated a different sensing property. The sensor using 10 wt% NiO-wrapped mesoporous TiO 2 composite microspheres showed a good sensitivity to different concentrations of ammonia from 10 ppm to 100 ppm whereas almost no response to other VOCs indicating an excellent selectivity to detect ammonia in the humid air with UV illumination at room temperature.
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NANO
·
2016
·
IF 0.951
Dewang Kong,Min Zhao,Shikuo Li,Fangzhi Huang,Jiming Song,Yupeng Yuan,Yuhua Shen,Anjian Xie
In this paper, a facile and efficient method combined sol–gel method with hydrothermal process was employed for preparing titanium dioxide (TiO 2 ) /reduced graphene oxide (rGO) nanocomposites without using any reductants or surfactants. This approach leads to the reduction of graphene oxide (GO) and the growth of TiO 2 nanorods simultaneously. The results reveal that the TiO 2 short nanorods with average size of 15 nm in length and 10 nm in diameter were uniformly grown on the rGO sheets with high dispersion. Compared with the pure TiO 2 nanoparticles, the TiO 2 /rGO composites exhibit strong absorption in the visible light range. The photocurrent density of nanocomposites reached 0.826 mA/cm 2 under the simulated sunlight illumination, which is 3.5 times than that of pure TiO 2 . An enhancement of photocatalytic hydrogen formation rate for the water splitting was observed over the TiO 2 /rGO composite photocatalysts, the fastest formation rate can reach 889.28 μ mol ⋅ g − 1 ⋅ h − 1 when TiO 2 coupling with 1wt.% rGO. Also the hydrogen production rate is about 3.27 times larger than pure TiO 2 and 2.23 times than P25 due to the excellent electron trapping and transportation properties of rGO and the synergistic effect between TiO 2 and rGO.
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CHEMOSPHERE
·
2014
·
IF 3.499
Yanjie Li,Chen Yang,Xuetao Guo,Zhi Dang,Xiaoqin Li,Qian Zhang
In this study, humic acids (HAs) from three sources, peat, sediment and straw, used to coat nano-TiO 2 were investigated. The results indicated that HAs isolated from peat were aromatic-rich, whereas those isolated from sediment and straw were aliphatic-rich. The nano-TiO 2 sedimentation experiments indicated that the presence of aromatic-rich HAs was more capable of stabilizing nano-TiO 2 particles than was the presence of aliphatic-rich HAs. This result is because the deionized phenolic groups in the HAs were preferentially adsorbed on the nano-TiO 2 surfaces, which generated a higher charge density on the nano-TiO 2 surfaces and caused stronger repulsive forces among particles. Furthermore, the aromatic-rich TiO 2 -HA complexes exhibited a greater sorption capacity than the aliphatic-rich TiO 2 -HAs complexes and nonlinear phenanthrene sorption because of their higher affinity and the condensed state of aromatic fractions. Note that natural organic matters, such as humic acids, in aquatic environments can not only increase the stability of nanoparticles but can also influence the mobility of hydrophobic organic compounds (HOCs).
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PubMed
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 33
·13565-13570
·
IF 0
Yingying Fan,Dongxue Han,Bin Cai,Weiguang Ma,Mohsin Javed,Shiyu Gan,Tongshun Wu,M. Siddiq,Xiandui Dong,Li Niu
TiO2 is an abundant and environmentally benign material, but has a wide band gap, which greatly confines its applications in photocatalysis. Doping and modifying the material composition are both generally used to change and control the photocatalytic activity of semiconductors. Herein, we describe a method and resulting activity of depositing Ce-/S-codoped TiO2 nanoparticles (NPs) on water-soluble sulfonated graphene (SGE) sheets, which guarantees a direct contact and satisfactory electron transfer between the semiconductor and graphene. The Ce/S–TiO2 NPs are homogeneously fixed on the surface of SGE sheets with an average particle size of ∼7 nm. The resulting composite showed noticeable activity in photodegrading methyl orange (κ = 0.425 h−1). This improved performance can be attributed to the synergistic effects of Ce- and S-codoping toward TiO2 and the composite action between TiO2 NPs and SGE. This type of novel composite is expected to stimulate the development of doped and graphene-involved photocatalysts for addressing environmental problems.
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BIOLOGICAL TRACE ELEMENT RESEARCH
·
2014
·Vol. 159
·期 1
·393-398
·
IF 1.608
Jin Chan,Wang Fude,Tang Ying,Zhang Xiangzhi,Wang Jianqiang,Yang Yongji
Graphene and its derivatives are increasingly applied in nanoelectronics, biosensing, drug delivery, and biomedical applications. However, the information about its cytotoxicity remains limited. Herein, the distribution and cytotoxicity of graphene oxide (GO) and TiO 2 -graphene oxide composite (TiO 2 -GO composite) were evaluated in A549 cells. Cell viability and cell ultrastructure were measured. Our results indicated that GO could enter A549 cells and located in the cytoplasm and nucleus without causing any cell damage. TiO 2 nanoparticles and GO would be separated after TiO 2 -GO composite entered A549 cells. TiO 2 -GO composite could induce cytotoxicity similar to TiO 2 nanoparticles, which was probably attributed to oxidative stress. These results should be considered in the development of biological applications of GO and TiO 2 -GO composite.
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PubMed
高影响因子
Journal of Central South University
·
2014
·Vol. 21
·期 5
·1714-1718
·
IF 0.464
Tang Yi-ping,Wang Shi-ming,Tan Xiao-xu,Hou Guang-ya,Zheng Guo-qu
A simple strategy to prepare a hybrid of nanocomposites of anatase TiO 2 /graphene nanosheets (GNS) as anode materials for lithium-ion batteries was reported. The morphology and crystal structure were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The electrochemical performance was evaluated by galvanostatic charge-discharge tests and alternating current (AC) impedance spectroscopy. The results show that the TiO 2 /GNS electrode exhibit higher electrochemical performance than that of TiO 2 electrode regardless of the rate. Even at 500 mA/g, the capacity of TiO 2 /GNS is 120.3 mAh/g, which is higher than that of TiO 2 61.6 mAh/g. The high performance is attributed to the addition of graphene to improve electrical conductivity and reduce polarization.
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JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 4
·2638-2647
·
IF 2.599
Xu Fang,Zhang Huaiwu,Jin Lichuan,Li Yuanxun,Li Jie,Gan Gongwen,Wei Miaoqin,Li Mingming,Liao Yulong
Transient electronic is an emerging field that designed electronic devices can be fleetly and partially (or completely) degraded when transiency is triggered. Here, a class of PVA-based degradable composite film was synthesized, whose physical properties allow it to be used as substrate material for transient electronic devices. We found the dielectric properties and dissolution rate of the composite film can be tuned by controlling the TiO 2 nanoparticle addition. Based on the as-synthesized PVA/TiO 2 composite film, patch antennas were further designed and fabricated. The antennas were found to possess excellent radiation performances at a frequency of 2.5 GHz. Most importantly, the antennas could be physically degraded within 1 h when immersed in pure water. This study shows that the PVA-based film is a good candidate substrate or supporting material for transient electronics. In addition, the design and manufacture methods reported here provide a reference for other transient devices with complex structure and function.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Yang Li,Peifu Wang,Cunping Huang,Weifeng Yao,Qiang Wu,Qunjie Xu
Despite high activity for photocatalytic degradation of organic dyes from water, nanoscale Ag 3 PO 4 photocatalyst particles are difficult to synthesize. As reported in literature, Ag 3 PO 4 particle sizes for photocatalytic degradation of water pollutants are normally larger than 100 nm. This research reports a facile and reproducible method for the synthesis of the ultrafine and uniform Ag 3 PO 4 nanoparticles loaded on the oxygen vacated TiO 2 (TiO 2 -OV) with average particle size as small as 2.6 nm. All obtained Ag 3 PO 4 particles can be completely loaded onto TiO 2 -OV support to form Ag 3 PO 4 /TiO 2 -OV composite photocatalysts. The prepared Ag 3 PO 4 /TiO 2 -OV photocatalyst exhibits much higher visible light photocatalytic activity than those of pure Ag 3 PO 4 or Ag 3 PO 4 /TiO 2 photocatalysts for the degradation of rhodamine b (Rh B) and phenol in water. After depositing thin layers of AgI on Ag 3 PO 4 ultrafine Ag 3 PO 4 nanoparticles, the new AgI-Ag 3 PO 4 /TiO 2 -OV composite photocatalysts not only show much higher photocatalytic activity, but they are also more stable than pure Ag 3 PO 4 catalyst. This new synthesis method will provide guidelines for the preparation of ultrafine nanoparticles and highly active photocatalysts for treatment of water pollution or production of hydrogen from water splitting/reducing.
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Catalysis Science & Technology
·
2017
·Vol. 7
·期 13
·2813-2818
·
IF 5.773
Yaping Lin,Yifeng Zhu,Xiulian Pan,Xinhe Bao
We demonstrate that the methanation activity of Ni catalysts is modulated by the crystal phase of the TiO2 support. The rutile TiO2 (r-TiO2)-supported Ni catalyst gives a turnover frequency almost two orders of magnitude higher than the anatase TiO2 (a-TiO2)-supported catalyst although the two catalysts exhibit a similar mean Ni particle size. Characterization by H2-TPR, H2-TPD, XPS and IR reveals a stronger interaction between Ni and r-TiO2, leading to a higher capability of CO activation and hydrogenation activity of Ni although Ni is partially covered by TiOx overlayers during reaction. Interestingly, the modulating effects of the titania crystal phases are much more pronounced on the activity of Ni in CO2 methanation.
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