scholarly journals Automobile Exhaust Removal Performance of Pervious Concrete with Nano TiO2 under Photocatalysis

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2088
Author(s):  
Guobao Luo ◽  
Hanbing Liu ◽  
Wenjun Li ◽  
Xiang Lyu
Keyword(s):  
Particle Size ◽  
Redox Potential ◽  
Photocatalytic Performance ◽  
Tio2 Particle ◽  
Pervious Concrete ◽  
Distribution Area ◽  
Light Sources ◽  
Nano Tio2 ◽  
Automobile Exhaust ◽  
The Government

The urban environment is facing serious problems caused by automobile exhaust pollution, which has led to a great impact on human health and climate, and aroused widespread concern of the government and the public. Nano titanium dioxide (TiO2), as a photocatalyst, can be activated by ultraviolet irradiation and then form a strong REDOX potential on the surface of the nano TiO2 particles. The REDOX potential can degrade the automobile exhaust, such as nitrogen oxides (NOx) and hydrocarbons (HC). In this paper, a photocatalytic environmentally friendly pervious concrete (PEFPC) was manufactured by spraying nano TiO2 on the surface of it and the photocatalytic performance of PEFPC was researched. The nano TiO2 particle size, TiO2 dosage, TiO2 spraying amount, and dispersant dosage were selected as factors to investigate the efficiency of photocatalytic degradation of automobile exhaust by PEFPC. Moreover, the environmental scanning electron microscope (ESEM) was used to evaluate the distribution of nano TiO2 on the surface of the pervious concrete, the distribution area of nano TiO2 was obtained through Image-Pro Plus, and the area ratio of nano TiO2 to the surface of the pervious concrete was calculated. The results showed that the recommended nano TiO2 particle size is 25 nm. The optimum TiO2 dosage was 10% and the optimum dispersant dosage was 5.0%. The photocatalytic performance of PEFPC was best when the TiO2 spraying amount was 333.3 g/m2. The change in the photocatalytic ratio of HC and NOx is consistent with the distribution area of nano TiO2 on the surface of the pervious concrete. In addition, the photocatalytic performance of PEFPC under two light sources (ultraviolet light and sunlight) was compared. The results indicated that both light sources were able to stimulate the photocatalytic performance of PEFPC. The research provided a reference for the evaluation of automobile exhaust removal performance of PEFPC.

scholarly journals Population Balance Application in TiO2 Particle Deagglomeration Process Modeling

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3523
Author(s):  
Radosław Krzosa ◽  
Łukasz Makowski ◽  
Wojciech Orciuch ◽  
Radosław Adamek
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Mechanistic Model ◽  
Population Balance ◽  
Tio2 Particle ◽  
Application Process ◽  
Titanium Dioxide Powder ◽  
Dioxide Powder ◽  
Computational Fluid Dynamics Cfd ◽  
Hydrodynamic Stresses

The deagglomeration of titanium-dioxide powder in water suspension performed in a stirring tank was investigated. Owing to the widespread applications of the deagglomeration process and titanium dioxide powder, new, more efficient devices and methods of predicting the process result are highly needed. A brief literature review of the application process, the device used, and process mechanism is presented herein. In the experiments, deagglomeration of the titanium dioxide suspension was performed. The change in particle size distribution in time was investigated for different impeller geometries and rotational speeds. The modification of impeller geometry allowed the improvement of the process of solid particle breakage. In the modelling part, numerical simulations of the chosen impeller geometries were performed using computational-fluid-dynamics (CFD) methods whereby the flow field, hydrodynamic stresses, and other useful parameters were calculated. Finally, based on the simulation results, the population-balance with a mechanistic model of suspension flow was developed. Model predictions of the change in particle size showed good agreement with the experimental data. Using the presented method in the process design allowed the prediction of the product size and the comparison of the efficiency of different impeller geometries.

scholarly journals Rat pulmonary responses to inhaled nano-TiO2: effect of primary particle size and agglomeration state

2013 ◽  
Vol 10 (1) ◽  
pp. 48 ◽  
Author(s):  
Alexandra Noël ◽  
Michel Charbonneau ◽  
Yves Cloutier ◽  
Robert Tardif ◽  
Ginette Truchon
Keyword(s):  
Particle Size ◽  
Primary Particle ◽  
Primary Particle Size ◽  
Nano Tio2 ◽  
Agglomeration State

scholarly journals Influence of nitrogen and air atmosphere during thermal treatment on micro and nano sized powders and sintered TiO2 specimens

2014 ◽  
Vol 46 (3) ◽  
pp. 365-375
Author(s):  
N. Labus ◽  
S. Mentus ◽  
Z.Z. Djuric ◽  
M.V. Nikolic
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Powder Particle ◽  
Rutile Phase ◽  
Nitrogen Atmosphere ◽  
Powder Particle Size ◽  
Nano Tio2 ◽  
Thermo Gravimetric ◽  
Air Atmosphere ◽  
Thermal Techniques

The influence of air and nitrogen atmosphere during heating on TiO2 nano and micro sized powders as well as sintered polycrystalline specimens was analyzed. Sintering of TiO2 nano and micro powders in air atmosphere was monitored in a dilatometer. Non compacted nano and micro powders were analyzed separately in air and nitrogen atmospheres during heating using thermo gravimetric (TG) and differential thermal analysis (DTA). The anatase to rutile phase transition temperature interval is influenced by the powder particle size and atmosphere change. At lower temperatures for nano TiO2 powder a second order phase transition was detected by both thermal techniques. Polycrystalline specimens obtained by sintering from nano powders were reheated in the dilatometer in nitrogen and air atmosphere, and their shrinkage is found to be different. Powder particle size influence, as well as the air and nitrogen atmosphere influence was discussed.

scholarly journals Enhanced Antibacterial Activity of Silver Doped Titanium Dioxide-Chitosan Composites under Visible Light

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1403 ◽  
Author(s):  
Jie Li ◽  
Bing Xie ◽  
Kai Xia ◽  
Yingchun Li ◽  
Jing Han ◽  
...  
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Titanium Dioxide ◽  
Visible Light ◽  
Silver Ions ◽  
Antibacterial Activities ◽  
Nano Tio2 ◽  
Inverse Emulsion ◽  
Potential Applications

Nano titanium dioxide (TiO2) with photocatalytic activity was firstly modified by diethanolamine, and it was then doped with broad spectrum antibacterial silver (Ag) by in situ method. Further, both Ag doped TiO2-chitosan (STC) and TiO2-chitosan (TC) composites were prepared by the inverse emulsion cross-linking reaction. The antibacterial activities of STC composites were studied and their antibacterial mechanisms under visible light were investigated. The results show that in situ doping and inverse emulsion method led to good dispersion of Ag and TiO2 nanoparticles on the cross-linked chitosan microsphere. The STC with regular particle size of 1–10 μm exhibited excellent antibacterial activity against E. coli, P. aeruginosa and S. aureus under visible light. It is believed that STC with particle size of 1–10 μm has large specific surface area to contact with bacterial cell wall. The increased antibacterial activity was attributed to the enhancement of both electron-hole separations at the surface of nano-TiO2 by the silver ions under the visible light, and the synergetic and sustained release of strong oxidizing hydroxyl radicals of nano-TiO2, together with silver ions against bacteria. Thus, STC composites have great potential applications as antibacterial agents in the water treatment field.

Preparation of europium-doped nano-TiO2 transparent photocatalyst emulsion and photocatalytic performance

2017 ◽  
Vol 10 (6) ◽  
pp. 760-767 ◽  
Author(s):  
孙建红 SUN Jian-hong ◽  
眭慧东 SUI Hui-dong ◽  
王紫薇 WANG Zi-wei ◽  
王 坤 WANG Kun ◽  
闫 勇 YAN Yong ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Nano Tio2

scholarly journals Crystallization of Nano-TiO2 Films based on Glass Fiber Fabric Substrate and Its Impact on Catalytic Performance

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 345-351
Author(s):  
Yunjuan Liu ◽  
Xiaohong Yuan ◽  
Yan Wang
Keyword(s):  
Photocatalytic Performance ◽  
Sol Gel ◽  
Crystal Form ◽  
Catalytic Performance ◽  
Indoor Environments ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Excellent Photocatalytic Activity ◽  
Activity Performance ◽  
Fiber Fabric

Abstract Nano-TiO2 film attracts great attention by its excellent photocatalytic activity performance. The application of nano-TiO2 film based on fabric substrate in indoor household textiles is helpful for purifying air and degrading formaldehyde content in indoor environments. In this paper, the nano-TiO2 films were prepared on fiberglass substrate by the sol-gel method, and the appearance of fabrics coated with nano-TiO2 at conditions of both without calcination (room temperature) and high temperature calcination (300∘C, 350∘C, 400∘C) was studied. In addition, X-ray diffraction technology was applied to analyze the crystallization of TiO2 film, with further discussion of the photocatalytic performance of degrading helianthin under UV irradiation.The results show that with increase of calcination temperature, the color of the fabric gets darker and darker until the powder peeling and dyeing reaches the maximum degree, the fabric becomes fragile, the anatase crystal form of TiO2 film tends to be complete, and the photocatalytic performance is improved. It is feasible to apply TiO2 film on the surface of fabrics in the design of indoor household textiles.

scholarly journals Preparation of TiO2 and Fe-TiO2 with an Impinging Stream-Rotating Packed Bed by the Precipitation Method for the Photodegradation of Gaseous Toluene

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1173 ◽  
Author(s):  
Guangping Zeng ◽  
Qiaoling Zhang ◽  
Youzhi Liu ◽  
Shaochuang Zhang ◽  
Jing Guo
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Packed Bed ◽  
Pure Tio2 ◽  
Precipitation Method ◽  
Nano Tio2 ◽  
X Ray ◽  
Rotating Packed Bed ◽  
Bet Analysis ◽  
Gaseous Toluene

Nano-TiO2 has always been one of the most important topics in the research of photocatalysts due to its special activity and stability. However, it has always been difficult to obtain nano-TiO2 with high dispersion, a small particle size and high photocatalytic activity. In this paper, nano-TiO2 powder was prepared by combining the high-gravity technique and direct precipitation method in an impinging stream-rotating packed bed (IS-RPB) reactor followed by Fe3+ in-situ doping. TiOSO4 and NH3·H2O solutions were cut into very small liquid microelements by high-speed rotating packing, and the mass transfer and microscopic mixing of the nucleation and growth processes of nano-TiO2 were strengthened in IS-RPB, which was beneficial to the continuous production of high quality nano-TiO2. Pure TiO2 and iron-doped nano-TiO2 (Fe-TiO2) were obtained in IS-RPB and were investigated by means of X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) and Brunauer–Emmett–Teller (BET) analysis, which found that pure TiO2 had a particle size of about 12.5 nm, good dispersibility and a complete anatase crystal at the rotating speed of packing of 800 rpm and calcination temperature of 500 °C. The addition of Fe3+ did not change the crystalline structure of TiO2. Iron was highly dispersed in TiO2 without the detection of aggregates and was found to exist in a positive trivalent form by XPS. With the increase of iron doping, the photoresponse range of TiO2 to visible light was broadened from 3.06 eV to 2.26 eV. The degradation efficiency of gaseous toluene by Fe-TiO2 under ultraviolet light was higher than that of pure TiO2 and commercial P25 due to Fe3+ effectively suppressing the recombination of TiO2 electrons and holes; the highest efficiency produced by 1.0% Fe-TiO2 was 95.7%.

scholarly journals Preparation and Properties of CaCO3-Supported Nano-TiO2 Composite with Improved Photocatalytic Performance

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3369
Author(s):  
Jie Wang ◽  
Sijia Sun ◽  
Lei Pan ◽  
Zhuoqun Xu ◽  
Hao Ding ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Interaction Mechanism ◽  
Pure Tio2 ◽  
Degradation Efficiency ◽  
Nano Tio2 ◽  
Composite Photocatalyst ◽  
Tio2 Particles ◽  
Grinding Machine

In order to improve the photocatalytic degradation efficiency of nano-TiO2, reduce its usage and realize recycling and reuse, CaCO3–TiO2 composite photocatalyst was prepared with calcium carbonate (CaCO3) and TiO2 in a grinding machine through the integration of grinding depolymerization, dispersion and particle composition. The photocatalytic degradation performance, recycling performance, structure and morphology of CaCO3–TiO2 were studied. The interaction mechanism between CaCO3 and TiO2 and the improvement mechanism for the photocatalytic performance of TiO2 were also discussed. The results show that under the UV light irradiation for 20 and 40 min, the degradation efficiency of methyl orange by the composite photocatalyst with 40% TiO2 (mass fraction) was 90% and 100%, respectively. This was similar to that of pure TiO2, and the performance of the composite photocatalyst was almost unchanged after five cycles. CaCO3–TiO2 is formed by the uniform loading of nano-TiO2 particles on the CaCO3 surface, and the nano-TiO2 particles are well dispersed. Due to the facts that the dispersion of nano-TiO2 is improved in the presence of CaCO3 and the charge transport capability is improved through the interfacial chemical bonds between CaCO3 and TiO2, the formation of this complex is an intrinsic mechanism to improve the photocatalytic efficiency of nano-TiO2 and reduce its usage in application processes.

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