APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Peng Yi-Zhu,Ma Wan-Hong,Jia Man-Ke,Zhao Xiao-Rong,David M. Johnson,Huang Ying-Ping
In this study, a weakly polar pesticide acetochlor in water was tried to degrade by BiOBr catalysts under visible light irradiation. Its degradation reaction rate increased exponentially with increasing catalyst dosage, which was significantly different from conventional photocatalytic patterns established for polar or water-soluble pollutants. Thus, the rate-dosage relationship of BiOBr/acetochlor was compared to that of BiOBr/Rhodamine B (RhB) (a typical strong polar dye pollutant in water) at different BiOBr dosages. The degradation rate of RhB increased with the BiOBr dosage and then plateaued due to more catalyst particles blocking the light into the inner solution, which is a typical behavior for heterogeneous photocatalysis of polar organic compounds in aqueous solution. While acetochlor behaved differently, its degradation rate increased exponentially with the BiOBr dosage, and no plateau was observed even up to 9.0 g/L BiOBr dosage. This special rate-dose relationship for weakly polar acetochlor was correlated with a unique adsorption property of BiOBr to acetochlor in water solution. There was a re-distribution effect that always exclude excessive acetochlor adsorbed on BiOBr surface regardless either substrates or BiOBr overdose. This finally resulted in every BiOBr particle having enough adsorption sites available for dissolved dioxygen to function thereby accelerate the degradation of weakly polar organic compounds in water.
研究领域:
环境化学
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光催化
·
水污染控制
·
环境功能材料
·
污染物降解机制
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DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 15
·7291-7299
·
IF 5.968
Jungang Hou,Zheng Wang,Wenbin Kan,Shuqiang Jiao,Hongmin Zhu,R. V. Kumar
Large-scale hydrogen production through water splitting using photocatalysts with solar energy can potentially produce clean fuel from renewable resources. In this work, photocatalytic evolution of H2 with a high efficiency was achieved using graphene oxide (GO) nanosheets decorated with CdS sensitized TaON core–shell composites (GO–CdS@TaON). The CdS@TaON core–shell nanocomposites were prepared by an ion-exchange route with assistance from a hydrothermal process on GO as the support. The TaON core–shell composites containing 1 wt% CdS nanocrystals showed a high rate of H2-production at 306 μmol h−1 with an apparent quantum efficiency (QE) of 15% under 420 nm monochromatic light. The rate of hydrogen formation was 68 times faster in comparison with the rate observed on pure TaON. The rate was further increased to 633 μmol h−1 with a high quantum efficiency of 31% when the GO–CdS@TaON hybrid composite was coupled with 1 wt% of graphene oxide and 0.4 wt% of Pt (about 141 times higher than that of the pristine TaON). This high photocatalytic H2-production activity is ascribed firstly to the presence of CdS nanocrystals that alter the energy levels of the conduction and valence bands in the coupled semiconductor system; secondly to the involvement of graphene oxide that serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS@TaON composites. This investigation can open up new possibilities for the development of highly efficient TaON-based photocatalysts that utilize visible light as an energy source.
研究领域:
材料化学
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光催化
·
能源科学
·
纳米材料
·
半导体物理
·
可再生能源
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Lingwei Lu,Meilin Lv,Gang Liu,Xiaoxiang Xu
Constituting solid solutions has been an appealing means to gain control over various physicochemical properties. In this work, we synthesized a series of SrTiO 3 -BiFeO 3 solid solutions and systematically explored their structural, optical and photocatalytic properties. Our results show that all solid solutions crystallize in a primitive cubic structure and their band gap values can be easily tuned by adjusting molar ratios between SrTiO 3 and BiFeO 3 . Photocatalytic hydrogen production under both full range and visible light irradiation is greatly improved after forming solid solutions. The highest hydrogen production rate obtained is ∼180 μmol/h under full range irradiation (λ ≥ 250 nm) and ∼4.2 μmol/h under visible light irradiation (λ ≥ 400 nm), corresponding to apparent quantum efficiency ∼2.28% and ∼0.10%, respectively. The activity is found to be strongly influenced by surface area and light absorption. Theoretical calculation suggests that Fe contributes to the formation of spin-polarized bands in the middle of original band gap and is responsible for the band gap reduction and visible light photocatalytic activity .
研究领域:
材料化学
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光催化
·
能源材料
·
无机固体化学
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半导体物理
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太阳能转化
·
表面科学
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DOI
高影响因子
FLAVOUR AND FRAGRANCE JOURNAL
·
2012
·Vol. 27
·期 5
·378-385
·
IF 1.424
Zhangfu Zeng,Yanxiong Fang,Hongbing Ji
The reason for low encapsulation efficiency of vanillin compared to p -hydroxybenzaldehyde within β -cyclodextrin was investigated. Fourier transform infrared spectra proved intermolecular interaction between guest and β -cyclodextrin. UV–visible studies indicated that vanillin and p -hydroxybenzaldehyde form 1:1 inclusion complexes with β -cyclodextrin. Nuclear magnetic resonance and quantum computational methods gave the most favourable orientation in which the guest molecule (vanillin or p -hydroxybenzaldehyde) is totally sequestered in the hydrophobic cavity of the cyclodextrin with the phenolic end located near the primary hydroxyls of the β -cyclodextrin and the aldehyde group near the secondary hydroxyls with hydrogen bonding formation. Encapsulation efficiency of the β -cyclodextrin inclusion with vanillin is about 29% lower than that with p -hydroxybenzaldehyde. This result could be attributable to the effect that the side chain methoxy group weakened the guest/host non-covalent intermolecular interaction, specifically, hydrogen bond interaction. Copyright © 2012 John Wiley & Sons, Ltd.
研究领域:
药物化学
·
超分子化学
·
分析化学
·
药剂学
·
分子识别
·
计算化学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Qing Cen,Qiaoyuan Gao,Chenlu Zhang,Yingqi Liu,Qi Wang,Qi Wang
In this study, visible-light-active iron tungstosilicate (FeSiW) was fabricated via solvothermal method . Fe 3+ was applied as counter ion to precipitate with silicotungstic acid (H 4 SiW 12 O 40 ) in methanol solution. It can be observed from FT-IR spectra that the Keggin structure of SiW 12 O 40 4− was well maintained in FeSiW. Besides, the effect of different initial molar ratios of Fe 3+ to H 4 SiW 12 O 40 was investigated (from 4:1 to 4:4). By photoelectrochemical characterizations, such as photocurrent response and Mott-Schottky (M-S) plots, easiest generation of electron-hole pairs and lowest charge transfer resistance can be observed on FeSiW with initial molar ratio of 4:3. Moreover, FeSiW with 4:3 ratio also displayed highest activity for photocatalytic reduction of Cr(VI), despite of the largest band gap (ca. 2.71 eV). The lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) of the optimized FeSiW were estimated to be +0.03 V and 2.74 V vs NHE, respectively, which were thermodynamically feasible for Cr(VI) reduction and H 2 O oxidation . Even under acidic condition (pH 3), the optimized photocatalyst displayed good stability in cyclic runs. Therefore, the present study opens a new way for heterogeneous polyoxometalates as efficient photocatalyst for environmental application.
研究领域:
环境化学
·
材料科学
·
光催化
·
无机化学
·
污染治理
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2011
·
IF 2.794
Yuanchao Pei,Jing Liu,Zhenning Yan,Zhiyong Li,Jing Fan,Jianji Wang
In this paper, the interactions between cationic dyes and the ionic liquids (ILs) have been studied by 31 P nuclear magnetic resonance (NMR), UV–Vis spectroscopy and conductometric measurements at different temperatures. It was shown that a decrease in the measured specific conductance of the (dye + IL) mixtures was caused by the formation of non-conducting or less conducting (dye + IL) associates. The associates were formed by 1:1 ratio of cation of the cationic dyes and anion of the ILs by using the 31 P NMR and UV–Vis spectroscopy methods. The association constants were calculated by theoretical model based on the deviation from linear behavior, and the association constants were as high as 10 6 (L · mol −1 ) 2 . Thermodynamic results imply that the formation process of association was exothermic nature. It is expected that the associates reported here would have promising application as active materials for the preparation of ion-selective electrode used in the determination of ILs concentrations.
研究领域:
物理化学
·
分析化学
·
胶体与界面化学
·
药物化学
·
分子生物学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Shunhang Wei,Rong Wu,Xiaoxiang Xu,Jikang Jian,Haixia Wang,Yanfei Sun
Black core-shelled anatase titania were successfully prepared using a simple one-step synthetic method by calcining colloid titania precursor in N 2 flow under atmospheric pressure. The physicochemical properties of the as-prepared samples were characterized by various techniques such as X-ray diffraction, high resolution transmission electron microcopy, etc. The samples demonstrate a unique core-shelled structure and electron paramagnetic resonance spectra reveal the presence of high concentration of Ti 3+ and oxygen vacancies at the surface, which accounts for their black appearance. A possible mechanism for the formation of such core–shell structure is proposed based on the results (X-ray photoelectron spectra, etc) of products prepared under different ration between urea and hydrochloric acid. Ethanol absolute is found to have critical effect in preventing phase transition of titania (from anatase to rutile) upon elevated temperatures. The black appearance of the sample powder (high visible light absorption) as well as slow electron/hole recombination rate after introducing oxygen vacancies/N species signify the core-shelled anatase titania as an efficient visible light active photocatalyst.
研究领域:
材料科学
·
光催化
·
纳米材料
·
表面化学
·
无机合成
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·Vol. 44
·期 3
·1586-1596
·
IF 4.229
Tianyu Zhao,Zipeng Xing,Ziyuan Xiu,Zhenzi Li,Shilin Yang,Qi Zhu,Wei Zhou
TiO 2-x /g-C 3 N 4 /CdS ternary heterojunctions are fabricated through thermal polymerization-chemical bath deposition combined with in-situ solid-state chemical reduction approach. The prepared materials are characterized by X-ray diffraction, Fourier transform infrared spectra , scanning electron microscopy, transmission electron microscopy , nitrogen adsorption-desorption, and X-ray photoelectron spectroscopy. The results show that the ternary heterojunctions are formed successfully and CdS quantum dots (QDs) and TiO 2 are anchored on surface of g-C 3 N 4 nanosheets simultaneously. The visible-light-driven photocatalytic degradation ratio of Bisphenol A and hydrogen production rate are up to 95% and ∼254.8 μmol h −1 , respectively, which are several times higher than that of pristine TiO 2 . The excellent visible-light-driven photocatalytic activity can be ascribed to the synergistic effect of TiO 2−x , g-C 3 N 4 and CdS QDs which extend the photoresponse to visible light region and favor the spatial separation of photogenerated charge carriers.
研究领域:
材料科学
·
光催化
·
纳米材料
·
环境催化
·
能源化学
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DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 20
·7296-7301
·
IF 5.101
Jungang Hou,Rui Cao,Zheng Wang,Shuqiang Jiao,Hongmin Zhu
Single-crystalline chromium doped bismuth titanate (Bi4Ti3−xCrxO12, x = 0.0–0.5) nanosheets with exposed {110} facets have been synthesized via a facile hydrothermal process. The Bi4Ti3−xCrxO12nanosheets possess well-defined tetragonal shapes with landscape dimension of 100–300 nm and thickness of 10–30 nm. The in-plane surfaces of the nanosheets lies on {001}, and the side surfaces are (110) and (10). Extension of the light absorption from the ultraviolet region to the visible-light region arises from the Cr 2p levels confirmed by XPS spectra. The Bi4Ti2.6Cr0.4O12 nanosheets with high stability showed the highest photocatalytic performance of H2 evolution from water under visible-light irradiation. Furthermore, the heterostructures by using the NiOx nanoparticles tightly coupled on the surface of Bi4Ti2.6Cr0.4O12 nanosheets, exhibited an enhanced photocatalytic activity due to the decrease in the recombination rate of the photoinduced electrons and holes, demonstrating that NiOx/Bi4Ti2.6Cr0.4O12 nanosheet is a promising candidate as a visible light photocatalyst.
研究领域:
材料科学
·
光催化
·
纳米材料
·
能源化学
·
半导体物理
·
表面科学
·
无机化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·Vol. 44
·期 31
·16348-16358
·
IF 4.084
Dandan Sun,Dechao Chi,Zekang Yang,Zipeng Xing,Junwei Yin,Zhenzi Li,Qi Zhu,Wei Zhou
Mesoporous g-C 3 N 4 /Zn–Ti layered double hydroxide (LDH)-laminated van der Waals heterojunction nanosheets were prepared by a facile one-step in situ hydrothermal method . Due to the strong electrostatic interactions between the positively charged Zn–Ti LDH and negatively charged g-C 3 N 4 nanocrystal , a laminated van der Waals heterostructure was successfully formed between Zn–Ti LDH and g-C 3 N 4 . The mesoporous g-C 3 N 4 /Zn–Ti LDH-laminated van der Waals heterojunction, which had a narrow bandgap of 2.41 eV extended the photoresponse to the visible light region. The obtained heterojunctions showed excellent visible-light-driven photocatalytic performance for the complete removal of ceftriaxone sodium (up to ∼97%) and a high hydrogen production rate (∼161.87 μmol h −1 g −1 ). This was mainly attributed to the formation of the laminated van der Waals heterojunctions, which favoured charge separation and the absorption of visible light, and the mesoporous structure, which provided more surface active sites. This facile strategy for preparing mesoporous g-C 3 N 4 /Zn–Ti LDH-laminated van der Waals heterojunctions offers new insights for the fabrication of high-performance van der Waals heterojunction photocatalytic materials.
研究领域:
材料科学
·
光催化
·
纳米材料
·
环境化学
·
能源化学
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DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2019
·Vol. 27
·期 12
·3053-3059
·
IF 1.911
Nianjun Kang,Dongbo Xu,Weidong Shi
In recent years, the excessive use of antibiotics has become a serious problem for human health. BiVO 4 regarded as one of the most promising visible-light-driven photocatalysts was used to degrade the antibiotics. In this paper, we fabricated Bi/BiVO 4 plasmonic photocatalysts which enhanced the photocatalytic activity of BiVO 4 for degradation of tetracycline (TC) antibiotic. The Bi/BiVO 4 photocatalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy . In addition, the photocatalytic experiment results show that the 0.04-Bi/BiVO 4 sample has the best photocatalytic activity for 2 times than the pure BiVO 4 photocatalyst. The cycle experiments, after four repetitions of the experiments, showed the sample still maintained a high photocatalytic activity. Finally, the photocatalytic reaction mechanism was also studied by free radical capture experiments and electron paramagnetic resonance spectroscopy .
研究领域:
环境化学
·
材料科学
·
光催化
·
纳米材料
·
环境污染治理
·
药物降解
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Xiaotong Sun,Luting Yan,Runxiang Xu,Mingyuan Xu,Yanyun Zhu
TiO 2 presents a broad application prospect in the field of degradation of environmental pollutants. However, the development of TiO 2 photocatalyst has been limited by two factors, namely, narrow spectral response range and low quantum efficiency . Surface coating can selectively change the physical and chemical properties of core particles, whereas the synergistic action between core and shell can optimize material performance. In this paper, surface modification of titanium dioxide (TiO 2 ) by dopamine polymerization was used to improve its photocatalytic performance. Among polydopamine (PDA)-modified TiO 2 , TiO 2 @PDA-0.4 mg/mL-2 h showed the best degradation rate of Rhodamine B (RhB): the degradation rate reached 99.28% and 77.40% after 1.5 h of ultraviolet–visible (UV–vis) and visible (Vis) light irradiation, respectively. Compared with the uncoated TiO 2 , the degradation rate has shown improvement, especially under Vis light irradiation, with the photocatalytic performance improving by 35.04%. Absorption, emission, and impedance spectra showed that surface modification of TiO 2 with suitable thickness of PDA effectively increased light absorption and promoted separation of photogenerated carriers . High-performance liquid chromatography–mass spectrometry revealed the differences in photocatalytic degradation mechanism of TiO 2 @PDA to RhB under UV–vis and Vis light irradiation. Compared with those under UV–vis light irradiation, the intermediate products under Vis light irradiation are relatively simple. TiO 2 @PDA generated more electrons, which interacted with H 2 O to produce large amounts of ·OH and holes under UV–vis light irradiation in comparison with that under Vis light irradiation. In addition to deacetylation , deamination , and decarboxylation by hydroxylation , excess ·OH in the photocatalytic process would attack benzene rings directly to produce N , N -diethylacetamide.
研究领域:
材料科学
·
环境化学
·
光催化
·
纳米材料
·
表面工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）