Enhancement of photocatalytic degradation of furfural and acetophenone in water media using nano-TiO2-SiO2 deposited on cementitious materials

2016 ◽  
Vol 74 (7) ◽  
pp. 1689-1697 ◽  
Author(s):  
Sahar Soltan ◽  
Hoda Jafari ◽  
Shahrara Afshar ◽  
Omid Zabihi
Keyword(s):  
Uv Irradiation ◽  
Room Temperature ◽  
Sol Gel ◽  
Oxygen Demand ◽  
Dip Coating ◽  
Cementitious Materials ◽  
Nano Particles ◽  
High Porosity ◽  
Visible Absorption ◽  
Operation Conditions

In the present study, silicon dioxide (SiO2) nanoparticles were loaded to titanium dioxide (TiO2) nano-particles by sol-gel method to make a high porosity photocatalyst nano-hybrid. These photocatalysts were synthesized using titanium tetrachloride and tetraethyl orthosilicate as titanium and silicon sources, respectively, and characterized by X-ray powder diffraction (XRD) and scanning electron microscope methods. Subsequently, the optimizations of the component and operation conditions were investigated. Then, nano-sized TiO2 and TiO2-SiO2 were supported on concrete bricks by the dip coating process. The photocatalytic activity of nano photocatalysts under UV irradiation was examined by studying the decomposition of aqueous solutions of furfural and acetophenone (10 mg/L) as model of organic pollutants to CO2 and H2O at room temperature. A decrease in the concentration of these pollutants was assayed by using UV-visible absorption, gas chromatography technique, and chemical oxygen demand. The removal of these pollutants from water using the concrete-supported photocatalysts under UV irradiation was performed with a greater efficiency, which does not require an additional separation stage to recover the catalyst. Therefore, it would be applicable to use in industrial wastewater treatment at room temperature and atmospheric pressure within the optimized pH range.

Fabrication of room temperature H2 gas sensor using pure and La: ZnO with novel nanocorn morphology prepared by sol–gel dip coating method

2014 ◽  
Vol 25 (10) ◽  
pp. 4339-4347 ◽  
Author(s):  
K. S. Venkatesh ◽  
K. Vijayalakshmi ◽  
K. Karthick ◽  
S. R. Krishnamoorthi ◽  
N. S. Palani ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Room Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Coating Method ◽  
Dip Coating Method

Silica Modified PP Fiber for Improving Crack-Resistance of Cementitious Composites

2011 ◽  
Vol 332-334 ◽  
pp. 2058-2064 ◽  
Author(s):  
Zhi Qian Yang ◽  
Jian Zhong Liu ◽  
Jia Ping Liu ◽  
Chang Feng Li ◽  
Hua Xin Zhou
Keyword(s):  
Crack Resistance ◽  
Sol Gel ◽  
Polypropylene Fiber ◽  
Chemical Deposition ◽  
Cementitious Materials ◽  
Nano Particles ◽  
Cement Matrix ◽  
Interfacial Property ◽  
Nano Silica ◽  
Fiber Matrix

To improve the interfacial bonding properties of polypropylene fiber-cement matrix, a new type of nano-silica modified polypropylene fibers was prepared by direct blend-spinning. As a comparison, Another polypropylene fiber was modified by surface chemical deposition of the silica particles by sol-gel method. The distribution of nano-particles on the fiber surface was observed with scanning electron microscope (SEM). This paper focuses on the effects on crack-resistance properties of fiber reinforced mortar(FRM) and present the mechanism of improving fiber-matrix interfacial properties, especially. The results demonstrate that the modified fiber with well-distributed of nano-silica has excellent mechanical properties, and crack resistance. The interfacial property of fiber-matrix is improved because of silica’s hydration activity. As the use of two kinds of modified fiber, the cementitious materials crack area is significantly decreased. In conclusion, the modified fiber by chemical deposition method which has slightly better overall performance.

scholarly journals Pengaruh kondisi operasi pada kinerja reaksi dekomposisi katalitik metana dalam reaktor gauze

2018 ◽  
Vol 9 (2) ◽  
pp. 69
Author(s):  
Widodo W Purwanto ◽  
Yuswan Muharam ◽  
Dwi Yulianti
Keyword(s):  
Stainless Steel ◽  
Methane Conversion ◽  
Sol Gel ◽  
Fixed Bed ◽  
Dip Coating ◽  
Space Time ◽  
Methane Decomposition ◽  
Fixed Bed Reactor ◽  
Feed Ratio ◽  
Operation Conditions

Methane decomposition is an alternative way to produce high quality carbon nanotubes (CNTs) and hydrogen simultaneously. The use of gauze reactor for methane decomposition had proven in solving pressure drop problem in fixed bed reactor. This experiment was carried out to study the effects of operation conditions (space time, temperature, and feed ratio) to gauze rector performance. Ni-Cu-Al catalyst which is prepared by sol-gel method with atomic ratio 2:1:1, was coated to Stainless Steel gauze by dip coating method. The reaction was done by flowing methane into the reactor at atmospheric pressure and varying space time (0.0006; 0.0032; 0.006 g×kat×min/mL), temperature (700, 750, and 800°C), and feed ratio CH4:H2 (1:0, 4:1, 1:1). An online gas chromatograph is used to detect the gas products. Reactor performances were observed from methane conversion, hydrogen purity, carbon yield and quality of nanocarbon that have been produced. Experiment result showed that the highest reactor performance (except nanocarbon quality) occurred at space time 0.006 gr cat min/mL, temperature 700 °C, and with pure methane as feed which give methane conversion, hydrogen purity, and yield carbon results are 90.66%, 90.16%, and 37 g carbon/g catalyt, respectively. Based on SEM analysis indicated that the best nanocarbon morphology can be gained at CH4:H2 ratio of 1:1.Keyword : methane decompotition, gauze reactor, carbon nanotube Abstrak Dekomposisi katalitik metana adalah salah satu alternatif untuk memproduksi hidrogen dan nanokarbon bermutu tinggi secara simultan. Penggunaan reaktor gauze untuk dekomposisi metana terbukti dapat mengatasi permasalahan penyumbatan pada reaktor unggun diam. Penelitian ini dilakukan untuk mengetahui pengaruh kondisi operasi (space time, temperatur, dan rasio umpan) terhadap kinerja reaktor gauze. Katalis Ni-Cu-Al disiapkan dengan menggunakan metode sol-gel dengan perbandingan atomik 2:1:1 dilapiskan pada gauze Stainless Steel dengan metode dip-coating. Reaksi dilakukan dengan mengalirkan metana ke dalam reaktor pada tekanan atmosferik dan dengan memvariasikan space time (0,0006; 0,0032; 0,006 g×kat×min/mL), temperatur (700, 750, dan 800 °C), dan rasio umpan CH4:H2 (1:0, 4:1, 1:1). Produk gas dianalisis dengan menggunakan gas chromatography yang terpasang secara online. Kinerja reaktor pada penelitian ini ditinjau dari konversi metana, kemurnian hidrogen, perolehan dan kualitas nanokarbon yang dihasilkan. Berdasarkan hasil eksperimen diketahui bahwa kinerja reaktor paling tinggi (kecuali kualitas nanokarbon) terjadi pada space time 0,006 g×kat×min/mL, temperatur 700 °C, dan dengan menggunakan metana murni yang memberikan hasil konversi metana, kemurnian hidrogen, serta perolehan karbon secara berturut-turut 90,66%, 90,16%, dan 37 gram karbon/gram katalis. Hasil analisis menggunakan SEM menunjukkan bahwa morfologi nanokarbon paling baik didapat pada komposisi reaktan CH4: H2 = 1:1.Kata Kunci : dekomposisi metana, reaktor gauze, karbon nanotube

Effect of SnO2 Addition into TiO2 Thin Films on Photocatalytic Activity and Hydrophilic Property

2014 ◽  
Vol 979 ◽  
pp. 90-93 ◽  
Author(s):  
Weerachai Sangchay ◽  
Tanarat Rattanakool
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Sol Gel ◽  
Dip Coating ◽  
Photocatalytic Activities ◽  
Self Cleaning ◽  
Xrd Techniques ◽  
Dip Coating Technique

The pure TiO2and SnO2-TiO2thin films on glass substrate were fabricated using a sol-gel dip coating technique. The thin films were annealed at the temperature of 700 °C for 2 h with the heating rate of 10 °C/min. The microstructures of the fabricated thin films were characterized by SEM and XRD techniques. The photocatalytic activities of the thin films were also tested by the degradation of methylene blue (MB) solution under UV irradiation. Finally, hydrophilic or self-cleaning properties of thin films were evaluated by measuring the contact angle of water droplet on the thin films with and without UV irradiation. It was found that 1 %mol SnO2-TiO2thin films shows the highest of photocatalytic activity and provide the most self-cleaning properties.

Photocatalytic and Self-Cleaning Properties of TiO2-Cu Thin Films on Glass Substrate

2012 ◽  
Vol 152-154 ◽  
pp. 409-413 ◽  
Author(s):  
Weerachai Sangchay ◽  
Lek Sikong ◽  
Kalayanee Kooptarnond
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Uv Irradiation ◽  
Sol Gel ◽  
Dip Coating ◽  
Glass Slides ◽  
Coating Method ◽  
Small Contact Angle ◽  
Self Cleaning ◽  
Dip Coating Method

TiO2-Cu thin films containing 0 to 1%Cu coated on glass slides were prepared by sol gel-dip coating method. The prepared thin films were synthesized at the temperature of 400 ◦C for 2 h with a heating rate of 10◦C/min. The microstructures of synthesized TiO2-Cu thin films were characterized by XRD, FT-IR and SEM. The photocatalytic activities of TiO-2Cu thin films were tested using methylene blue (MB) solution under UV irradiation. Finally, the self-cleaning property was evaluated by means of contact angle of water droplet on the films. The results show all samples have the thickness in range of 1 um and surfaces are dense with a large surface area. It can be noted that TiO2-1.0Cu thin films were found to give the highest photocatalytic efficiency and exhibited self-cleaning effect (small contact angle, 17°) under UV irradiation.

Photocatalytic Degradation of Reactive Brilliant Blue KN-R by N, Fe- TiO2/FFA

2011 ◽  
Vol 183-185 ◽  
pp. 2028-2031
Author(s):  
Gui Rong Wang
Keyword(s):  
Ph Value ◽  
Sol Gel ◽  
Dip Coating ◽  
Brilliant Blue ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Operation Conditions ◽  
First Order Kinetics ◽  
Fe Ions

TiO2 photocatalyst modified by N and Fe ions was loaded on self-made fly ash forming adsorbent (FFA) using the sol-gel dip-coating process. The crystal structure and photoadsorption ability was characterized by X-ray diffraction (XRD) and UV-Vis spectrophotometer, respectively. The photo catalytic degradation of Reactive Brilliant Blue KN-R using N, Fe-TiO2/FFA was examined. Effects of initial dye concentration, pH value and hydrogen peroxide dosage on degradation were studied. The degradation of the organic molecule followed a pseudo-first-order kinetics according to the Langmuir model. Under the optimum operation conditions, 30 mg/L KN-R could be decolorized over 97.47% within 75 min.

scholarly journals Synthesis of silica nanoparticles to enhance the fire resistance of cement mortars

Fire Research ◽  
2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Joana Vaz-Ramos ◽  
Aldina Santiago ◽  
António Portugal ◽  
Luísa Durães
Keyword(s):  
Thermal Conductivity ◽  
Silica Nanoparticles ◽  
Fire Resistance ◽  
Room Temperature ◽  
Sol Gel ◽  
Cementitious Materials ◽  
Pozzolanic Reactivity ◽  
Cement Mortars ◽  
Hydrolysis And Condensation ◽  
Strength And Durability

Silica nanoparticles are known to enhance the strength and durability of cementitious materials, due to their nanofilling effect and their high pozzolanic reactivity. They also have the potential to improve their thermal properties and fire resistance. However, these improvements are highly dependent on the nanoparticles’ characteristics. In this work, silica nanoparticles were prepared by sol-gel reaction and a design of experiments with four factors was used to conclude about the parameters that have more influence in the synthesis of these nanoparticles and, thus, optimize this process and the particles’ properties. Using a lower ethanol/water, higher hydrolysis and condensation time and higher volume of catalyst, the smallest particle size was obtained (118 nm). The effect of the incorporation of these silica nanoparticles into cement mortars was studied in terms of density and thermal conductivity of these mortars, after curing at room temperature. The presence of silica nanoparticles led to an increase in density and decrease of thermal conductivity. The mortars were also exposed to high temperature, which originated a significant reduction (~50%) in their thermal conductivity.

Mechanical Properties of Organic-Inorganic Hybrid Black Coating of Silica and Polyurethane

2009 ◽  
Vol 423 ◽  
pp. 161-165 ◽  
Author(s):  
Aziz Rebati ◽  
Manuel Piñero ◽  
Nicolás de la Rosa-Fox ◽  
Luis Maria Esquivias Fedriani
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
Metallic Copper ◽  
Dip Coating ◽  
Polymer Composition ◽  
Glass Substrates ◽  
Hybrid Silica ◽  
Black Coating ◽  
Organic Silica

The mechanical properties of black thin film on glass substrates and metallic, obtained from the synthesis of organic-inorganic silica hybrids via sol-gel are described. Hybrid silica-based coatings with tetraethoxysilane (TEOS), methyltrietoxysilane (MTES), polyurethane (PU) and commercial silica colloidal solution (Ludox HS30) as precursors, were used. The procedure is divided in the following three steps: 1) obtaining homogenous and stable solutions of different organic silica-polymer composition, 2) aggregation of the black pigment with the formulate FeMnOx, 3) Coating substrates by both dip-coating and aerograph airbrush, at room temperature. The films obtained were characterized by SEM, AFM and nano-indentation. The coatings of the Ludox-MTES-PU/FeMnOx system showed the better characteristics concerning the morphology and the adhesion to the glass and metallic copper substrates

Substrate Influenced Nucleation and Crystallization of LiNbO3 Thin Films Made by Sol-Gel

1993 ◽  
Vol 310 ◽  
Author(s):  
Vikram Joshi ◽  
Debasis Roy ◽  
Martha L. Mecartney
Keyword(s):  
Thin Films ◽  
Amorphous Carbon ◽  
Room Temperature ◽  
Sol Gel ◽  
Dissipation Factor ◽  
Dip Coating ◽  
Polycrystalline Films ◽  
Heteroepitaxial Growth ◽  
Oriented Polycrystalline ◽  
Deposited Films

AbstractLithium niobate films were deposited on amorphous carbon, silicate glass, (0001) sapphire, and (100) silicon by spin or dip coating double metal ethoxide sols. The crystallinity and microstructure of the deposited films were examined by XRD and TEM. Crystallization behavior and resulting microstructure were strongly influenced by the type of substrate. The formation of crystalline LiNbO3 on amorphous carbon was detected at room temperature. Randomly oriented polycrystalline films were obtained on glass at 400°C. Choice of one mole of water per mole of ethoxide generated heteroepitaxial growth of LiNbO3 thin films on (0001) sapphire. Oriented but polycrystalline films were obtained on silicon. The electrical behavior of film on silicon was evaluated in metal-ferroelectric-semiconductor configuration. A dielectric constant of 35 and a dissipation factor of 0.004 was measured at 100 KHz.

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