MOLECULES
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2017
·Vol. 22
·期 11
·1943
·
IF 2.861
Xiaojia Li,Mingming Zou,Yang Wang
Highly crystalline mesoporous anatase TiO2nanospheres with high surface area (higher than P25 and anatase TiO2) are prepared by a soft-template method. Despite the high specific surface area, these samples have three times lower equilibrium adsorption (<2%) than Degussa P25. The rate constant of the mesoporous anatase TiO2(0.024 min−1) reported here is 364% higher than that of P25 (0.0066 min−1), for the same catalytic loading. The results of oxidation-extraction photometry using several reactive oxygen species (ROS) scavengers indicated that mesoporous anatase TiO2generates more ROS than P25 under UV-light irradiation. This significant improvement in the photocatalytic performance of mesoporous spherical TiO2arises from the following synergistic effects in the reported sample: (i) high surface area; (ii) improved crystallinity; (iii) narrow pore wall thicknesses (ensuring the rapid migration of photogenerated carriers to the surface of the material); and (iv) greater ROS generation under UV-light.Keywords:mesoporous anatase TiO2;high surface area;photocatalytic
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2016
·
IF 2.76
Hongqiang Li,Shunxing Mu,Xiaoqing Weng,Yunliang Zhao,Shaoxian Song
The adsorption of Pb 2+ at the rutile/water interface has been studied for the activation of rutile flotation with salicyl hydroxamic acid (SHA) as a collector in this work. This study was performed through measurement of the zeta potential, adsorption capacity, calorimetry and X-ray photoelectron spectroscopy. The experimental results showed that the adsorption of SHA on rutile and the flotability of rutile were significantly improved by the addition of Pb 2+ . This improvement was attributed to the specific adsorption of Pb 2+ in the form of PbOH + , which interacted with the Ti-OH at the rutile surface and formed a surface Ti-O-Pb + complex. This adsorption followed the Langmuir model. It reversed the zeta potential sign of rutile at pH 5.5⿿6.8 and had a heat of adsorption of ⿿46.71 kJ/mol, suggesting the occurrence of a chemiosorptive process.
研究领域:
矿物加工工程
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物理化学
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DOI
高影响因子
Nanoscale
·
2013
·Vol. 5
·期 24
·12150-12155
·
IF 6.233
Shunxing Li,Jie Chen,Fengying Zheng,Yancai Li,Fuying Huang
A novel double-shell TiO2 hollow sphere with an inner anatase shell and an outer rutile shell was synthesized by a simple sol–gel method and silica protected calcination process. The structure and formation mechanism was proposed based on characterization using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The double-shell spheres have a uniform diameter of 360 nm and a typical yolk–shell structure. Moreover, the double-shell TiO2 hollow spheres possess a large specific surface area (169 m2 g−1). Due to the high surface area, multiple light reflection and beneficial electron conduction between the inner anatase and outer rutile shell of this special structure, the as-prepared double-shell TiO2 catalysts show remarkably enhanced photoactivity compared to the commercial P25 catalyst. In particular, rhodamine B molecules can be completely decomposed in the presence of the double-shell spheres after 60 minutes of irradiation with UV light. In addition, the high activity is retained after five cycles, indicating the stability and reusability of the double-shell catalyst.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CHEMICAL COMMUNICATIONS
·
2014
·Vol. 50
·期 21
·2755-2757
·
IF 6.718
Zhao Zhao,Huaqiao Tan,Haifeng Zhao,Yang Lv,Li-Jing Zhou,Yujiang Song,Zaicheng Sun
Stable reduced TiO2 rutile nanorods with well-defined facets were prepared by a solvothermal route in the presence of Zn powder. The oxygen vacancy in the TiO2 nanorods, which can be tuned by the amount of Zn, results in a narrow band gap and visible-light photocatalytic activity.
研究领域:
材料科学
·
化学
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DOI
PubMed
高影响因子
Catalysts
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2018
·Vol. 8
·期 5
·215
·
IF 3.465
Tongyao Wang,Ming Xia,Xueqian Kong
Photocatalytic reduction of CO2into fuels is a promising route to reduce greenhouse gas emission, and it demands high-performance photocatalysts that can use visible light in the solar spectrum. Due to its broadband light adsorption, polydopamine (PDA) is considered as a promising photo-sensitization material for semiconductor photocatalysts. In this work, titanium oxides have been coated with PDA through an in-situ oxidation polymerization method to pursue CO2reduction under visible light. We have shown that the surface coated PDA with a thickness of around 1 nm can enhance the photocatalytic performance of anatase under visible light to reduce CO2into CO. Assisted with additional UV-vis adsorption and photoluminescence characterizations, we confirmed the sensitization effect of PDA on anatase. Furthermore, our study shows that thicker PDA coating might not be favorable, as PDA could decompose under both visible and UV-vis light irradiations.13C solid-state nuclear magnetic resonance showed structural differences between thin and thick PDA coatings and revealed compositional changes of PDA after light irradiation.Keywords:photocatalysis;CO2reduction;anatase;polydopamine;sensitization
研究领域:
环境科学
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材料科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2015
·
IF 7.435
Yanfeng Cao,Xiaoting Li,Zhenfeng Bian,Addis Fuhr,Dieqing Zhang,Jian Zhu
A facile solvothermal approach was used to prepare brookite-type TiO 2 nanocrystals with different phase content and structure, accomplished by adjusting the ratio of TiCl 4 to t -BuOH. The obtained biphasic brookite/rutile TiO 2 nanocrystals showed a high brookite weight content (72%). The photocatalytic degradation of phenol under UV-irradiation was used to determine the synergetic effect from the combination of different phases ( e.g. , brookite, anatase, and rutile). The biphasic NST-4 composed of brookite and rutile exhibited the highest degradation rates, with rate constants three times higher than commercial Degussa P-25. Detailed analysis found that, besides phase composition and content, the semi-embedded structure was essential to obtain a superior activity of biphasic TiO 2 samples.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
Kangning Liu,Jiliang Ma,Xiaopan Yang,Dongnv Jin,Yancong Li,Gaojie Jiao,Shuangquan Yao,Shaolong Sun,Runcang Sun
Photocatalytic biorefinery catches an ocean of attention because of its environmental friendliness. It is widely known that photocatalytic performance of TiO 2 is poor due to the wide bandgap and sluggish electron kinetics. Herein, biochar nanosheet and anatase TiO 2 (denoted as a- TiO 2 @MC) were combined to accelerate the charge separation/transfer and narrow the bandgap of TiO 2 , which is proved by UPS and Mott-Schottky plot analysis. With improved electron kinetics, comes excellent photocatalytic performance, which gave great yield of xylonic acid (52.26%) and lactic acid (49.22%). Furthermore, h + ,·OH, and 1 O 2 exerted positive effects on the synthesis of biomass-derived organic acids, in which the h + plays the major role in the biorefinery over a- TiO 2 @MC, whereas the·O 2 - is not. 1000-fold scale-up experiment indicated that 69.1% of the photocatalytic performance was achieved when compared with the similar conditions irradiated by visible light. This work provides an efficient photocatalytic biorefinery via a facile and low-cost way.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
SOLID STATE IONICS
·
2021
·
IF 3.785
Lihua Wang,Yandi Cai,Baochun Liu,Lin Dong
In this report, we present a facile approach for the synthesis of a brown TiO 2 material rich in oxygen vacancies under atmospheric conditions with titanium tetrachloride, oxalic acid and anhydrous ethanol as raw materials. The samples were characterized by X-ray diffraction (XRD), UV–vis diffuse reflectance (UV–vis DRS), Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), High resolution transmission electron microscope (HRTEM), Fourier transform infrared (FTIR) and Raman. The visible light photocatalytic activity of the samples was evaluated by degrading of methylene blue solution. XRD and Raman results showed that the brown TiO 2 was anatase TiO 2 . XPS and EPR indicated the presence of abundant oxygen vacancies in the brown TiO 2 . UV–vis DRS illustrated that the brown TiO 2 had a strong absorption in the visible light region. The photocatalytic activity measurement indicated that the visible light photocatalytic performance of the brown TiO 2 was excellent. The surface oxygen vacancies played a key role for the significant enhancement of the brown TiO 2 photocatalytic performance.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2017
·
IF 9.446
Jun Xiao,Weiyi Yang,Qi Li
Bi quantum dots were deposited onto rutile TiO 2 nanoparticles by a one-pot, solvent-thermal process to create the Bi/TiO 2 (rutile) heterojunction photocatalyst. Due to the specific semimetal property of Bi, a metal to semiconductor transition occurred for Bi quantum dots, which endowed them with the hole trapping capability to enhance the charge carrier separation in rutile TiO 2 and eliminate the need of sacrificial agents for the consumption of photogenerated holes in photocatalytic reduction process. The Bi/TiO 2 (rutile) heterojunction photocatalyst demonstrated an efficient photocatalytic bromate reduction under visible light illumination without the addition of sacrificial agents in the reaction solution, and it could be easily regenerated for reuse. Different with previously reported noble/transition metal modifications as the electron trapping center, this study demonstrated a novel material design strategy of the introduction of hole trapping centers to create photocatalysts with strong photocatalytic reduction capabilities, which could be readily adopted for a broad range of technical applications.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 19
·期 1
·171-178
·
IF 3.849
Yan Zheng,Xiao Zhang,Ping Yang
Anatase hexagonal prism TiO2 with high thermal stability was prepared through the decomposition of precursors (HTiOF3). HTiOF3 was firstly synthesized, using a solvothermal method, from n-octanol, tetrabutyl titanate and hydrofluoric acid. The obtained precipitates were then calcined at different temperatures (200–900 °C) for 2 h. The formation process of the hexagonal prism HTiOF3 precursors included three steps: nuclei growth, dissolution–recrystallization and further growth. The morphologies of the precursors depended strongly on the reaction temperature and the amount of solvent. The precursors were transformed into TiO2 after calcination and the effect of the calcination temperature on the morphology and phase composition of the hexagonal prism TiO2 was investigated. The results indicated that the anatase hexagonal prism TiO2 exhibited a rather high thermal stability, maintaining both the anatase structure and precursor shape up to 800 °C. The sample that was calcined at 550 °C exhibited a superior photocatalytic performance.
研究领域:
材料科学
·
纳米技术
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DOI
高影响因子
ChemCatChem
·
2018
·Vol. 11
·期 3
·1057-1063
·
IF 4.674
Gan Wang,Lijuan Zhang,Baolin Yan,Jianmin Luo,Xintai Su,Fan Yue
Graphical It's a vacancy-rich world ! During the liquid-nitrogen quenching process, the isolated O atoms on the TiO 2 surface are partially frozen and lose the opportunity to return the crystallographic sites, leaving abundant oxygen vacancy on the surface. The oxygen vacancy-rich TiO 2 prepared via liquid-nitrogen quenching exhibited outstanding advantages on photocatalytic H 2 evolution. Development of novel methods to obtain highly active catalysts for photocatalytic hydrogen evolution is desired. This work reports a facile preannealing-quenching strategy to synthesize oxygen vacancy-rich anatase TiO 2 hollow spheres. TiO 2 hollow spheres are first synthesized via a versatile kinetics-controlled coating method and then subjected to high temperature preannealing followed by rapid quenching in liquid-nitrogen (−196 °C). The as-quenched samples appear light grey suggesting the presence of abundant surface oxygen vacancies, which are subsequently confirmed by the comprehensive analyses of XRD, XPS and EPR spectra. The oxygen vacancies induced by quenching process are proved to have promoted the light adsorption and inhibited the recombination of photo-induced charges for TiO 2 hollow spheres, which obviously improve the photocatalytic performance of those samples. The results showed that the TiO 2 hollow spheres quenched at 500 °C exhibited a robust stability and the most excellent photocatalytic performance for hydrogen evolution (413.5 μmol h −1 ) over other quenched samples and it displayed 1.51 times higher performance than that of samples normally cooled at 500 °C (273.7 μmol h −1 ). Herein, this liquid-nitrogen quenching strategy presented here provides an effective route for the synthesis of high-performance TiO 2 for water splitting and have a promising prospect in the other application.
研究领域:
材料科学
·
催化
·
纳米技术
·
能源转换
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产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2022
·
IF 8.431
Wenya Ao,Junshen Qu,Hejie Yu,Yang Liu,Chenglong Liu,Jie Fu,Jianjun Dai,Xiaotao Bi,Yanxin Yuan,Yajie Jin
A furfural residue-derived activated carbon (AC) supported black-TiO 2 photocatalyst was successfully prepared by ultrasonic-assisted sol-gel treatment (USG) and solvothermal treatment (ST) combined with microwave-assisted heating (MH). The prepared composites were characterized and evaluated based on the degradation of tetracycline hydrochloride (TC) under ultraviolet (UV) illumination. The average TiO 2 nanoparticle size of the as-synthesized catalysts was between 9 and 11 nm. The bandgap of TiO 2 -USGM was 1.6 eV, much lower than that of other reference catalysts. Organic carbon and AC in the catalyst play positive roles in reducing the band gap (e.g. 1.6∼2.6 eV) and improving visible-light absorption. The oxygen vacancies are responsible for UV–visible absorption. Adding AC into black TiO 2 resulted in a lower degree of recombination of photogenerated electrons. Mott-Schottky plots showed that AC-containing TiO 2 @AC-STM reduced the value of conduction band value from −0.59 eV to −0.24 eV, which is beneficial to photogenerated electrons. Compared with TiO 2 , the Ti–O–C and Ti–C- in TiO 2 @AC remarkably improved the adsorption and catalytic efficiency of TC. In a near-neutral pH environment, TiO 2 @AC-STM and TiO 2 @AC-USGM exhibited high removal efficiencies (88.0% and 75.7%, respectively) and degradation rates (0.0418 and 0.0302 μmol/g/s, respectively) at a catalyst load of 0.25 g/L. Notably, the catalyst can be effectively used over a wide range of pH (6–9). The solution pH after treatment was close to neutral, which is advantageous for wastewater treatment . The activation energies were found to be approximately 3.47 kJ/mol. The thermodynamic parameters showed that the photodegradation process was non-spontaneous and endothermic. Based on the trapping experiments, O 2 ⋅ - was mainly responsible for TC photodegradation over TiO 2 @AC-STM, followed by h + . The TC degradation pathways and catalyst stability were also investigated. Biomass-derived carbon-supported catalysts have great potential for waste biomass utilization as green, and low-cost catalysts.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
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