scholarly journals Fotocatálisis aplicada a la degradación de pesticidas (Profenofos) vertidos en el lago de Tota

2021 ◽  
Vol 16 (2) ◽  
pp. 87-95
Author(s):  
Ángela María Rubiano Barrera
Keyword(s):  
Sol Gel ◽  
Degussa P25

Este trabajo tiene como objetivo principal evaluar la remoción de un pesticida vertido en el lago de Tota mediante degradación fotocatalítica. El contaminante seleccionado fue Profenofos, principio activo del Awake 500 EC, agroquímico usado en los cultivos de cebolla larga ubicados en la ronda del lago. En la fase experimental, se utilizaron dos métodos de degradación fotocatalítica: suspensión de catalizador TiO2 Degussa P25 e inmovilización de sol-gel de nanopartículas de titanio NTO en vidrio. La fuente de radiación utilizada en laboratorio y a nivel piloto fue una lámpara uv que simula la radiación solar. Se analizó el efecto del tiempo de radiación y la masa de fotocatalizador sobre la concentración del compuesto degradado. Para la determinación analítica de Profenofos se utilizó espectrofotometría uv-Vis y cromatografía de gases con detector n/p y de captura de electrones. El fotocatalizador soportado fue caracterizado con sem, rayos x e ir. Los resultados obtenidos muestran un alto porcentaje de remoción y reflejan el potencial que la fotocatálisis tiene en la degradación de agroquímicos presentes en aguas del lago de Tota.

Preparation and Photocatalytic Activity of Mixed Phase Anatase/rutile TiO2 Nanoparticles for Phenol Degradation

2014 ◽  
Vol 70 (2) ◽  
Author(s):  
Mohamad Azuwa Mohamed ◽  
Wan Norharyati Wan Salleh ◽  
Juhana Jaafar ◽  
Norhaniza Yusof
Keyword(s):  
Photocatalytic Activity ◽  
Tio2 Nanoparticles ◽  
High Performance ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Chemical Properties ◽  
Mixed Phase ◽  
Rutile Tio2 ◽  
Physico Chemical ◽  
Degussa P25

The evolution of desirable physico-chemical properties in high performance photocatalyst materials involves steps that must be carefully designed, controlled, and optimized. This study investigated the role of key parameter in the preparation and photocatalytic activity analysis of the mixed phase of anatase/rutile TiO2 nanoparticles, prepared via sol-gel method containing titanium-n-butoxide Ti(OBu)4 as a precursor material, nitric acid as catalyst, and isopropanol as solvent. The prepared TiO2 nanoparticles were characterized by means of XRD, SEM, and BET analyses, and UV-Vis-NIR spectroscopy. The results indicated that the calcination temperature play an important role in the physico-chemical properties and photocatalytic activity of the resulting TiO2 nanoparticles. Different calcination temperatures would result in different composition of anatase and rutile. The photocatalytic activity of the prepared mixed phase of anatase/rutile TiO2 nanoparticles was measured by photodegradation of 50 ppm phenol in an aqueous solution. The commercial anatase from Sigma-Aldrich and Degussa P25 were used for comparison purpose. The mixed phase of anatase/rutile TiO2 nanoparticles (consists of 38.3% anatase and 61.7% rutile) that was prepared at 400°C exhibited the highest photocatalytic activity of 84.88% degradation of phenol. The result was comparable with photocatalytic activity demonstrated by Degussa P25 by 1.54% difference in phenol degradation. The results also suggested that the mixed phase of anatase/rutile TiO2 nanoparticles is a promising candidate for the phenol degradation process. The high performance of photocatalyst materials may be obtained by adopting a judicious combination of anatase/rutile and optimized calcination conditions.

scholarly journals Photocatalytic efficiency of titanium dioxide immobilized on PVP/AAc hydrogel membranes: A comparative study for safe disposal of wastewater of Remazol Red RB-133 textile dye

2005 ◽  
Vol 7 (4) ◽  
pp. 181-185 ◽  
Author(s):  
Hoda S. Hafez ◽  
A. El-Hag Ali ◽  
M. S. A. Abdel-Mottaleb
Keyword(s):  
Sol Gel ◽  
Textile Wastewater ◽  
Textile Dye ◽  
Photocatalytic Efficiency ◽  
Safe Disposal ◽  
Hydrogel Membranes ◽  
Different Types ◽  
Degussa P25 ◽  
Gel Technique ◽  
Remazol Red

The paper reports on the photocatalytic efficiency ofTiO2nanoparticles immobilized on polyvinyl pyrrolidone/acrylic acid (PVP/AAc) copolymer hydrogels, which are prepared by means ofγ-rays induced homo- and copolymerization. The efficiency of immobilized photocatalyst is tested on a commercial textile dye namely Remazol Red RB-133. The results are compared with photocatalytic efficiencies of different types of non supportedTiO2photocatalysts such as aqueous slurries of colloidalTiO2prepared by sol-gel technique, and commercially available Degussa P25. Although less efficient than nonsupported ones, the hydrogel supportedTiO2photocatalyst has the practical advantages of easy separation and removal from the reactors. This makes it a viable technique for the safe disposal of textile wastewater into the water streams.

Modification of Solvolytic Sol-Gel Synthesis for Low Temperature TiO2 DSSC Photoelectrode

2014 ◽  
Vol 979 ◽  
pp. 39-42
Author(s):  
Saran Kalasina ◽  
Taweechai Amornsakchai ◽  
Udom Asawapirom
Keyword(s):  
Low Temperature ◽  
Tin Oxide ◽  
Hydrofluoric Acid ◽  
Sol Gel ◽  
Cell Efficiency ◽  
Dye Sensitized ◽  
Degussa P25 ◽  
Main Component ◽  
Sol Gel Synthesis ◽  
Dry Film

Solvolytic sol-gel synthesis was applied for the low temperature production of photoelectrode for dye-sensitized solar cell (DSSC). In this study, commercial TiO2 standard (Degussa P25) was used as the main component in the preparation of photoelectrode film. Addition of TiO2 gel prepared from a solvolytic sol-gel method reduced cracking in the dry film while still maintains porosity. Further modification by simply adding hydrofluoric acid (HF) and ammonia (NH3) increase porosity and improve interconnection between fluorine doped tin oxide (FTO) layer on the substrate and the coated TiO2 layer even under low temperature baking condition (<150°C). The modified TiO2 electrode showed significantly better electrical and electrochemical properties. Furthermore, the DSSC cell with modified TiO2 film also showed higher cell efficiency when compared with the controlled cell that used only Degussa P25.

Cement Bonded Sol-Gel TiO2 Powder Photocatalysis for Phenol Removal

2015 ◽  
Vol 776 ◽  
pp. 271-276 ◽  
Author(s):  
Nor Hafizah ◽  
Iis Sopyan
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Xrd Analysis ◽  
Hydrolysis Rate ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Phenol Removal ◽  
Titanium Tetraisopropoxide ◽  
Degussa P25

Photocatalysis has been proven effective in controlling various environmental problems originated by pollutions both in liquid and gaseous phases. Titanium dioxide (TiO2) is well known the most practical photocatalyst as it has high photocatalytic efficiency, low band gap energy, and no toxicity. Various chemical methods have been tried to produce TiO2 photocatalyst powder with high activity. In this study, sol-gel method has been employed to produce nanosized TiO2 photocatalyst particles and its physical properties and photocatalytic activity in phenol degradation test were compared with the commercial TiO2 powder, Degussa P25. The synthesis process was carried out through hydrolysis of titanium tetraisopropoxide (TPT) and methanol where the molar ratio of water to TPT was monitored to control the hydrolysis rate. From X-Ray Diffraction (XRD) analysis, the sol-gel TiO2 powder obtained was fully in anatase structure with high crystallinity. Scanning Electron Microscope (SEM) measurement showed that the powder was in nanoto sub-micron size, spherical in shape, and tightly agglomerated. Thermal analysis confirmed that sol-gel derived amorphous TiO2 powder transformed to anatase phase after 400°C calcination. The test on photocatalytic performance conducted using aqueous solution of phenol as the representative of water pollutant examined in this study showed that the sol-gel TiO2 powder is more efficient in degrading phenol compared to one of the most active photocatalysts commercially available, Degussa P25.

scholarly journals SÍNTESIS SOL-GEL DE DIÓXIDO DE TITANIO PARA EL PROCESO DE FOTODEGRADACIÓN

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Sandra Cipagauta Díaz ◽  
José Ricardo Gómez Romero ◽  
Francisco Javier Tzompantzi Morales ◽  
Agileo Hernández Gordillo ◽  
Hugo Alfonso Rojas Sarmiento
Keyword(s):  
Sol Gel ◽  
Palabras Clave ◽  
Degussa P25 ◽  
Para Determinar

<span>Para este trabajo se sintetizaron materiales nanoestructurados de dióxido de titanio por el método Sol-Gel, a baja temperatura. El pH de gelación se fijó en 3 (TiO2-a) y 9 (TiO2-b), se calcinaron a 500 °C, con el fin de estudiar lainfluencia del pH en las propiedades electrónicas, ópticas y estructurales en el proceso de fotodegradación.Los resultados indican que los semiconductores poseen tamaños de partículas entre 7 y 10 nm. Las áreas superficiales específicas de los materiales, determinadas por el método BET, son: 80 m2/g TiO2-a y 61 m2/g TiO2-b, muy superiores a la obtenida con la titania Degussa P25 (50 m2/g). La espectroscopia UV-vis de reflectancia difusa se utilizó para determinar la distancia energética entre bandas(Egp) de los materiales, teniendo el siguiente orden: Egp (TiO2-a) &lt; Egp (TiO2-b) &lt; Egp (Degusa P25). Los DRX sugieren que los materiales son principalmente faseanatasa. La imagen de TEM muestra que el TiO2-a presenta un menor tamaño de partículas (5 nm) en comparación con el otro semiconductor. La actividad fotocatalítica se probó en la degradación de 4-nitrofenol (4NP). La mineralización del contaminante hasta el 98% (TOC), se obtuvo con la muestra de TiO2-a, exhibiendo la más alta fotoactividad.</span><br /><strong>Palabras clave:</strong><span> Dióxido de titanio, fotocatálisis, 4-nitrofenol, mineralización, síntesis Sol-Gel.</span>

Antibacterial Activity of TiO2 and Fe3+ Doped TiO2 Nanoparticles Synthesized at Low Temperature

2011 ◽  
Vol 214 ◽  
pp. 197-201 ◽  
Author(s):  
Saowaluk Boonyod ◽  
Weerawan Sutthisripok ◽  
Lek Sikong
Keyword(s):  
Antibacterial Activity ◽  
Low Temperature ◽  
Anatase Phase ◽  
Sol Gel ◽  
Fluorescent Light ◽  
Oh Radicals ◽  
Tio2 Powder ◽  
Nanocrystalline Tio2 ◽  
E Coli ◽  
Degussa P25

Nanocrystalline TiO2 powder with and without Fe3+ doping were successfully synthesized at low temperature by a microwave-assisted sol–gel method. The synthesized TiO2 powders were characterized by XRD, BET, FT-IR and SEM. It was found that anatase phase was formed after refluxed at 80°C using a domestic microwave oven. Antibacterial behavior towards E. coli was then studied under UV and fluorescent irradiation. The synthesized pure TiO2 powder exhibited superior antibacterial activity under fluorescent irradiation compared to the commercial TiO2 (Degussa P25). It can efficiently destroy E. coli bacteria after 20 min with UV irradiation and 3 h with fluorescent light; this good activity is mainly related to the high OH radicals on its surface. It was also observed that the synthesized powders have smaller crystallite size and larger specific surface area than those of Degussa P25 due to the absence of high temperature calcination requirement.

A Comparative Study of Supported TiO2 as Photocatalyst in Water Decontamination at Solar Pilot Plant Scale

2005 ◽  
Vol 128 (3) ◽  
pp. 331-337 ◽  
Author(s):  
Mahmut Kus ◽  
Wolfgang Gernjak ◽  
Pilar Fernández Ibáñez ◽  
Sixto Malato Rodríguez ◽  
Julián Blanco Gálvez ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Organic Compounds ◽  
High Performance ◽  
Sol Gel ◽  
Silver Deposition ◽  
Force Microscopy ◽  
Glass Tubes ◽  
Degussa P25 ◽  
Pilot Plant Scale

The degradation of gallic acid and imidacloprid with supported Millennium PC500 and Degussa P25 TiO2 is reported. TiO2 particles were immobilized using a titanium sol-solution and direct deposition on glass supports. The film characterization was done by x-ray diffraction, scanning electron microscopy, and atomic force microscopy, and degradation of organic compounds was monitored by high-performance liquid chromatography, total organic carbon analyzer, and ion chromatography. The experiments were performed under sunlight in compound parabolic collector plants with flat supports inside the glass tubes. Photocatalytic activity of the films was compared and identified. Although sol-gel coatings had better mechanical properties, mineralization was observed to be approximately five times slower than paste-deposited films. Photoactivity of the films decreased with silver deposition due to the nature of the organic compounds. The rate constants were calculated to be between 2×10−1 and 6×10−2mgm2∕kJ for organic compounds, and 6×10−2 and 6×10−3 for total organic carbon.

scholarly journals Nanocrystalline TiO2with enhanced photoinduced charge separation as catalyst for the phenol degradation

2006 ◽  
Vol 2006 ◽  
pp. 1-6 ◽  
Author(s):  
Carmen Canevali ◽  
Franca Morazzoni ◽  
Roberto Scotti ◽  
Ignazio Renato Bellobono ◽  
Marco Giusti ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Charge Separation ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Lower Surface ◽  
Morphological Properties ◽  
High Catalytic Activity ◽  
Photoinduced Charge Separation ◽  
Degussa P25 ◽  
Photoinduced Charge

Nanocrystalline TiO2catalysts based on pure rutile (R100) and a 30% of anatase and 70% of rutile (R70) were synthesized by the sol-gel method, using Pluronic PE 6400 as templating agent. Catalysts were characterized in terms of structural and morphological properties; moreover, the formation of paramagnetic charge carriers under UV irradiation was studied and related to the activity of TiO2in the photoinduced degradation of phenol. With respect to Degussa P25, the two sol-gel catalysts show lower surface area and a wider pore size distribution. The EPR spectra recorded under UV irradiation show enhanced charge separation in the sol-gel samples, with the O−species in higher amount than in Degussa P25. This result is in agreement with the high catalytic activity of R100 sample in the photoinduced degradation of phenol, very similar to that displayed by Degussa P25 and higher than that of R70 sample.

Ionic Liquid-Assisted Synthesis of Anatase Nanostructured TiO2 Aerogel Doped with Fe3+ by a Low Temperature Sol-Gel Process and its Photocatalytic Performance

2013 ◽  
Vol 785-786 ◽  
pp. 365-369
Author(s):  
Ning Ning Wang ◽  
Chun Ling Yu ◽  
Hong Yi Dai ◽  
Ying Huan Fu ◽  
Guo Lin Shao ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Low Temperature ◽  
Photocatalytic Performance ◽  
Ambient Pressure ◽  
Sol Gel ◽  
Crystallization Rate ◽  
Sol Gel Process ◽  
Degussa P25 ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

Anatase crystalline TiO2 aeroge and TiO2 aerogel doped with Fe3+ were prepared at low temperature (60°C) using ionic liquid (IL) assisted sol-gel method. In this system, ionic liquid was not only an effective solvent but also an important template, which enhanced the polycondensation and crystallization rate, facilitated the formation of anatase crystal. Due to the effect of template, anatase crystalline TiO2 aerogel can be synthesized at the aging temperature of 60°C and drying under ambient pressure. The as-synthesized samples were characterized by X-ray power diffraction (XRD), scanning electron microscopes (SEM). The photocatalytic performance of pure TiO2 aerogel and TiO2 aerogel doped with Fe3+ aerogel was evalutaed by decolorization of reactive brilliant blue under visible light irridation. The results indicated that TiO2 aerogel doped with Fe3+ exhibited higher photocatalytic activity than pure TiO2 aerogel and Degussa P25.

Synthesis and Properties of Ni-Doping Nano-TiO2 Photocatalysts

2013 ◽  
Vol 320 ◽  
pp. 688-692
Author(s):  
Yu Ping Luo ◽  
Jin Zhang ◽  
Zhong Qi Zhu ◽  
Qiang Liu ◽  
Qing Ju Liu
Keyword(s):  
Photocatalytic Activity ◽  
Size Distribution ◽  
Doping Concentration ◽  
Sintering Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Molar Ratio ◽  
Fluorescent Lamp ◽  
Ni Doping ◽  
Degussa P25

Ni-doping TiO2 photocatalysts were synthesized by sol-gel method and characterized by XRD, Size Distribution and PL instruments. Meanwhile, the degradation of methyl blue (MB) was investigated under fluorescent lamp to test the photocatalytic activity of the samples with different Ni-doping concentration and sintered at different temperature. The results show that the photocatalytic activity of TiO2 photocatalysts is much higher than that of Degussa P25. The optimum preparation parameters are that the pH value is 2.5, Ni: Ti=0.01 (molar ratio) and sintering temperature is 500°C.

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