scholarly journals Decolorization of crystal violet over TiO2 and TiO2 doped with zirconia photocatalysts

2017 ◽  
Vol 71 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Marija Vasic ◽  
Marjan Randjelovic ◽  
Jelena Mitrovic ◽  
Nikola Stojkovic ◽  
Branko Matovic ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Uv Light ◽  
Sol Gel ◽  
Chemical Properties ◽  
Dye Decolorization ◽  
Operational Parameters ◽  
Physico Chemical ◽  
Irradiation Treatment ◽  
Catalytic Material ◽  
Reaction Cycles

Titania based catalyst and TiO2 doped with zirconia were prepared by modified sol?gel method. The synthesized catalysts samples were characterized by BET, XRD, SEM and FTIR techniques. Photocatalytic activity was tested in the reaction of crystal violet (CV) dye decolorization/decomposition under UV light irradiation. The effect of several operational parameters, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment and number of reaction cycles were also considered. The obtained results indicated faster dye decolorization with the increase of the catalyst amount and a decrease of initial CV concentrations. An influence of doping with zirconia on the physico-chemical properties of bare titania was studied. The doping procedure had affected photocatalytic properties of the final catalytic material, and had improved photocatalytic performances of doped catalyst on crystal violet decolorization/degradation in comparison to bare titania.

scholarly journals Degradation of crystal violet over heterogeneous TiO2-based catalysts: The effect of process parameters

2016 ◽  
Vol 10 (3) ◽  
pp. 189-198 ◽  
Author(s):  
Marija Vasic ◽  
Marjan Randjelovic ◽  
Milan Momcilovic ◽  
Branko Matovic ◽  
Aleksandra Zarubica
Keyword(s):  
Crystal Violet ◽  
Uv Light ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Operational Parameters ◽  
Calcination Temperatures ◽  
Photocatalytic Effect ◽  
Dye Decolourization ◽  
Catalyst Dosage ◽  
Doped Titania

In this study, modified sol-gel method was employed to synthesize the pure and Zr-doped titania catalysts. Brunauer-Emmett-Teller (BET) method was applied to determine porosity, X-ray diffraction (XRD) analysis was used to study crystal structure, scanning electron microscopy (SEM) was used to investigate morphology and Fourier transform infrared spectroscopy (FTIR) was used to examine surface properties/total acidity of the obtained catalysts samples. Photocatalytic activity was tested in the reaction of crystal violet (CV) dye decolourization/degradation under UV light irradiation. The effects of several photocatalysis operational parameters were considered, such as catalyst dosage, initial dye concentrations, duration of UV irradiation treatment, as well as catalysts calcination temperatures and dopant amounts. The obtained results indicated faster dye decolourization/degradation with the increase of the catalyst dosage and the decrease of initial CV concentrations. The Zr-doping affects photocatalytic properties, i.e. CV decolourization/degradation of the prepared catalytic materials. Thus, addition of 5 wt.% of ZrO2 to titania increases photocatalytic effect for ~15% and addition of 10 wt.% of ZrO2 improves the photocatalytic efficiency of titania for nearly 30%.

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 In situ sol-gel synthesis of hyaluronan derivatives bio-nanocomposite hydrogels

2019 ◽  
Vol 6 (5) ◽  
pp. 249-258 ◽  
Author(s):  
U D’Amora ◽  
A Ronca ◽  
M G Raucci ◽  
S M Dozio ◽  
H Lin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Filler Concentration ◽  
Similar Degree ◽  
Nanocomposite Hydrogels ◽  
Physico Chemical ◽  
Inorganic Fillers ◽  
Sol Gel Synthesis ◽  
Physical Blending

Abstract The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid (HA) followed by the development of nanocomposite hydrogels directly in situ by biomineralization of photocrosslinkable HA polymers through sol-gel synthesis. In this way, it has been possible to overcome some limitations due to classical approaches based on the physical blending of inorganic fillers into polymer matrix. To this aim, methacrylated and maleated HA, synthesized with similar degree of substitution (DS) were compared in terms of mechanical and physico-chemical properties. The success of in situ biomineralization was highlighted by reflect Fourier transform infrared spectroscopy and thermogravimetric analysis. Furthermore, mechanical characterization demonstrated the reinforcing effect of inorganic fillers evidencing a strong correlation with DS. The swelling behavior resulted to be correlated with filler concentration. Finally, the cytotoxicity tests revealed the absence of toxic components and an increase of cell proliferation over culture time was observed, highlighting these bio-nanocomposite hyaluronan derivatives as biocompatible hydrogel with tunable properties.

scholarly journals Technologies and Formulation Design of Polysaccharide-Based Hydrogels for Drug Delivery

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3156 ◽  
Author(s):  
Giulia Auriemma ◽  
Paola Russo ◽  
Pasquale Del Gaudio ◽  
Carlos A. García-González ◽  
Mariana Landín ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Drying Methods ◽  
Special Focus ◽  
Porous Network ◽  
Hydrogel Particles ◽  
Physico Chemical ◽  
Droplet Production ◽  
Inflammatory Drugs ◽  
Sol Gel Transition

Polysaccharide-based hydrogel particles (PbHPs) are very promising carriers aiming to control and target the release of drugs with different physico-chemical properties. Such delivery systems can offer benefits through the proper encapsulation of many drugs (non-steroidal and steroidal anti-inflammatory drugs, antibiotics, etc) ensuring their proper release and targeting. This review discusses the different phases involved in the production of PbHPs in pharmaceutical technology, such as droplet formation (SOL phase), sol-gel transition of the droplets (GEL phase) and drying, as well as the different methods available for droplet production with a special focus on prilling technique. In addition, an overview of the various droplet gelation methods with particular emphasis on ionic cross-linking of several polysaccharides enabling the formation of particles with inner highly porous network or nanofibrillar structure is given. Moreover, a detailed survey of the different inner texture, in xerogels, cryogels or aerogels, each with specific arrangement and properties, which can be obtained with different drying methods, is presented. Various case studies are reported to highlight the most appropriate application of such systems in pharmaceutical field. We also describe the challenges to be faced for the breakthrough towards clinic studies and, finally, the market, focusing on the useful approach of safety-by-design (SbD).

Physico-Chemical Properties of Silica Coated Superparamagnetic Magnetite Nanoparticles Synthesized by Non-Seeded Process

2015 ◽  
Vol 1107 ◽  
pp. 267-271
Author(s):  
Sodipo Bashiru Kayode ◽  
Azlan Abdul Aziz
Keyword(s):  
Silica Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Colloidal Suspension ◽  
Sol Gel ◽  
Chemical Properties ◽  
Colloidal Suspensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Physico Chemical ◽  
Physical And Chemical

The science of core-shell nanoparticles requires investigation into several physical and chemical properties of the composite nanoparticles. Unlike the conventional sol-gel or the reverse microemulsion micelle method, we presented here a non-seeded process of encapsulating superparamagnetic magnetite nanoparticles (SPMN) with silica. Physico-chemical analysis of the product was used to confirm the result of the coating procedure. Colloidal suspension of SPMN and silica nanoparticles were synthesised through coprecipitation method and modified Stöber method respectively. Afterwards, both colloidal suspensions of SPMN and silica nanoparticles were sonicated to encapsulate the SPMN with silica. Elemental mapping of the composite particles with electron spectroscopy imaging (ESI) confirmed the core-shell micrograph of the SPMN and silica. The X-ray diffraction pattern (XRD) showed the silica shell to be in amorphous form. FTIR analysis further confirmed the chemical properties of the product to be silica coated SPMN.

Influence of gelation time on the morphological and physico-chemical properties of the sol–gel entrapped lipase

2008 ◽  
Vol 52-53 ◽  
pp. 27-33 ◽  
Author(s):  
Rubiane C. Pinheiro ◽  
Cleide M.F. Soares ◽  
Onélia A.A. dos Santos ◽  
Heizir F. de Castro ◽  
Flavio F. de Moraes ◽  
...  
Keyword(s):  
Sol Gel ◽  
Gelation Time ◽  
Chemical Properties ◽  
Physico Chemical

Preparation of Sulfated Zirconia Using Modified Sol Gel Method

2014 ◽  
Vol 896 ◽  
pp. 153-158
Author(s):  
Anis Kristiani ◽  
Kiky C. Sembiring ◽  
Fauzan Aulia ◽  
Joddy Arya Laksmono ◽  
Silvester Tursiloadi ◽  
...  
Keyword(s):  
Sulfated Zirconia ◽  
Sol Gel ◽  
Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Organic Bases ◽  
Physico Chemical ◽  
Medium Porosity ◽  
Cetyltrimethyl Ammonium ◽  
Physical And Chemical

A series of sulfated zirconia was prepared through sol gel method in alcohol medium. Porosity of the catalyst was developed in two different methods, which were immersion of cetyltrimethyl ammonium chloride (CTAC) surfactant as templating agent and Supercritical Fluid Extraction (SFE). The physico-chemical properties of the catalysts were characterized by Thermal Gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) and gravimetry method for acidity measurement following by the adsorption of organic bases. The characterization results show that different method of immersing CTAC surfactant and SFE affecting physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity.

A comparative study on the physico–chemical properties of sol–gel electrospun cobalt oxide nanofibres from two different polymeric binders

RSC Advances ◽  
2015 ◽  
Vol 5 (99) ◽  
pp. 81429-81437 ◽  
Author(s):  
Gibin George ◽  
S. Anandhan
Keyword(s):  
Comparative Study ◽  
Cobalt Oxide ◽  
Sol Gel ◽  
Chemical Properties ◽  
Chemical Characteristics ◽  
Polymeric Binder ◽  
Physico Chemical ◽  
Polymeric Binders

Physico–chemical characteristics of cobalt oxide nanofibres were tailored by varying the sacrificial polymeric binder in sol–gel electrospinning.

Modification of Clinoptilolite by Synthetic Zeolite

1993 ◽  
Vol 58 (8) ◽  
pp. 1782-1790
Author(s):  
Ľubomír Medvecký ◽  
Jaroslav Briančin ◽  
Ján Mihalik
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Methanol Conversion ◽  
Synthetic Zeolite ◽  
Al Content ◽  
Physico Chemical ◽  
Sol Gel Process ◽  
Dta And Tg ◽  
High Al Content ◽  
Selection Of

The sol-gel process allows to modify clinoptilolite by the nucleation of synthetic zeolite. From the viewpoint of methanol conversion, the obtained high Al content nucleation-deposited zeolite decreases the catalytic activity of clinoptilolite. Therefore, it is necessary to optimize the selection of suitable synthetic zeolite as to its composition. Contamination of zeolite surfaces by carbonaceous fragments during catalytic process results from physico-chemical properties of the used and processed zeolite, and according to DTA and TG analysis it significantly affects the readsorption of water vapours and likely also the zeolite activity in methanol conversion.

Structural and Photocatalytic Property of CaTiO3 Nanosphere

2020 ◽  
Vol 979 ◽  
pp. 169-174 ◽  
Author(s):  
C. Karthikeyan ◽  
M. Thamima ◽  
S. Karuppuchamy
Keyword(s):  
Dye Degradation ◽  
Uv Light ◽  
Chemical Properties ◽  
Photocatalytic Property ◽  
Advanced Characterization ◽  
Morphological Studies ◽  
Physico Chemical ◽  
Raman Study ◽  
Ft Ir ◽  
Xrd Patterns

The nanostructured photocatalysts are the most promising materials for the degradation of toxic dyes. Particularly, CaTiO3 has been used in several applications including catalytic, optical, biological and electronic. In this present study, perovskite structured CaTiO3 nanomaterials have been synthesized by microwave irradiation method. The physico-chemical properties of the prepared CaTiO3 nanomaterials were studied by various advanced characterization techniques. The XRD patterns confirm the presence of perovskite structure of the prepared nanomaterials. FT-IR analysis confirms the presence of Ca-Ti-O vibrational bonds. Micro Raman study display the existence of O-Ca-Ti-O with B1g mode of vibrations. Morphological studies revealed the presence of truncated nanospheres. The dye degradation property of prepared CaTiO3 was investigated by Malachite green (MG) by UV-light.

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