Sol-gel synthesized rutile TiO2 nanoparticles loaded with Cardamom essential oil: Enhanced antibacterial activity

Author(s):  
Oussama Ouerghi ◽  
Mohammed H. Geesi ◽  
Elmutasim O. Ibnouf ◽  
Mohammad Javed Ansari ◽  
Pravej Alam ◽  
...  
2014 ◽  
Vol 70 (2) ◽  
Author(s):  
Mohamad Azuwa Mohamed ◽  
Wan Norharyati Wan Salleh ◽  
Juhana Jaafar ◽  
Norhaniza Yusof

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.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2996 ◽  
Author(s):  
Jing He ◽  
Yi-en Du ◽  
Yang Bai ◽  
Jing An ◽  
Xuemei Cai ◽  
...  

Anatase/rutile mixed-phase TiO2 nanoparticles were synthesized through a simple sol-gel route with further calcination using inexpensive titanium tetrachloride as a titanium source, which effectively reduces the production cost. The structural and optical properties of the prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis adsorption. The specific surface area was also analyzed by Brunauer–Emmett–Teller (BET) method. The anatase/rutile mixed-phase TiO2 nanocomposites containing of rod-like, cuboid, and some irregularly shaped anatase nanoparticles (exposed {101} facets) with sizes ranging from tens to more than 100 nanometers, and rod-like rutile nanoparticles (exposed {110} facets) with sizes ranging from tens to more than 100 nanometers. The photocatalytic activities of the obtained anatase/rutile mixed-phase TiO2 nanoparticles were investigated and compared by evaluating the degradation of hazardous dye methylene blue (MB) under ultraviolet light illumination. Compared to the commercial Degussa P25-TiO2, the mixed-phase TiO2 nanocomposites show better photocatalytic activity, which can be attributed to the optimal anatase to rutile ratio and the specific exposed crystal surface on the surface. The anatase/rutile TiO2 nanocomposites obtained at pH 1.0 (pH1.0-TiO2) show the best photocatalytic activity, which can be attributed to the optimal heterojunction structure, the smaller average particle size, and the presence of a specific exposed crystal surface. The enhanced photocatalytic activity makes the prepared anatase/rutile TiO2 photocatalysts a potential candidate in the removal of the organic dyes from colored wastewater.


2021 ◽  
Vol 8 (2) ◽  
pp. 21-27
Author(s):  
Abeer Abd Saleh ◽  
Quraish Abbas ◽  
Seenaa Ibraheim ◽  
Ibrahim Muhammed ◽  
Mayes Sameer Hameed ◽  
...  

In this research, preparation of titanium dioxide nanomaterial (TiO2) using sol-gel method was achieved. 2.5 g weight of the titanium dioxide nanoparticles were added to the local paint using the casting method. Thin films were prepared by drop casting the paint onto the surface of pre-prepared samples, then several tests were carried out including adhesion test, hardness test (Shore B), brightness and whiteness, friction test, contact angle, and antibacterial activity. The nanomaterial at a percentage of 12% showed the best results when it was added to the paint. These results include adhesion strength, hardness strength, and exposing to weather conditions of temperature, and humidity. The adhesive strength increased when adding the nanomaterial from 112 to 139 before exposure to the weather and from 58 to 108 after exposure. The hardness also increased from 77.9 to 86.5 before exposure to the surrounding environment and from 94.2 to 96.8 after exposure. In addition, the paint with TiO2 nanoparticles exhibited antibacterial activity against two types of bacteria Escherichia coli (E. coli), staphylococcus aurous (S. aurous) and antifungal candida. Paint with TiO2 nanoparticles is more efficient as antibacterial agents with E. coli as compared with S. aurous and candida.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1052 ◽  
Author(s):  
Yanxiang Li ◽  
Jessica Tian ◽  
Chuanfang Yang ◽  
Benjamin Hsiao

Cellulose is a natural polymer that is widely used in daily life, but it is susceptible to microorganism growth. In this study, a simple sol–gel technique was utilized to incorporate the cellulose scaffold with Ag/TiO2 nanoparticles. The morphology and crystal structure of the as-prepared Ag/TiO2/cellulose composite film were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. Antibacterial tests involving the use of Escherichia coli (E. coli) were carried out under dark and UV-light conditions to evaluate the efficiency of the Ag/TiO2/cellulose composite film in comparison with pristine cellulose paper and TiO2/cellulose composite film. The results indicated that the antibacterial activity of the Ag/TiO2/cellulose composite film outperformed all other samples, where the Ag content of 0.030 wt% could inhibit more than 99% of E. coli. This study suggests that finely dispersed nanocale Ag/TiO2 particles in the cellulose scaffold were effective at slowing down bacterial growth, and the mechanisms of this are also discussed.


2018 ◽  
Vol 16 (S1) ◽  
pp. S48-S54
Author(s):  
Y. Ez zoubi ◽  
S. Lairini ◽  
A. Farah ◽  
K. Taghzouti ◽  
A. El Ouali Lalami

The purpose of this study was to determine the chemical composition and to evaluate the antioxidant and antibacterial effects of the Moroccan Artemisia herba-alba Asso essential oil against foodborne pathogens. The essential oil of Artemisia herba-alba was analyzed by gas chromatography coupled with mass spectroscopy. The antibacterial activity was assessed against three bacterial strains isolated from foodstuff and three bacterial strains referenced by the ATCC (American Type Culture Collection) using the disk diffusion assay and the macrodilution method. The antioxidant activity was evaluated using the DPPH (2, 2-diphenyl-1- picrylhydrazyl) method. The fourteen compounds of the Artemisia herba-alba essential oil were identified; the main components were identified as β-thujone, chrysanthenone, α-terpineol, α-thujone, α-pinene, and bornyl acetate. The results of the antibacterial activity obtained showed a sensitivity of the different strains to Artemisia herba-alba essential oil with an inhibition diameter of 8.50 to 17.00 mm. Concerning the MICs (minimum inhibitory concentrations), the essential oil exhibited much higher antibacterial activity with MIC values of 2.5 μl/ml against Bacillus subtilis ATCC and Lactobacillus sp. The essential oil was found to be active by inhibiting free radicals with an IC50 (concentration of an inhibitor where the response is reduced by half) value of 2.9 μg/ml. These results indicate the possible use of the essential oil on food systems as an effective inhibitor of foodborne pathogens, as a natural antioxidant, and for potential pharmaceutical applications. However, further research is needed in order to determine the toxicity, antibacterial, and antioxidant effects in edible products.


2018 ◽  
Vol 16 (S1) ◽  
pp. S155-S163 ◽  
Author(s):  
S. Mehalaine ◽  
O. Belfadel ◽  
T. Menasria ◽  
A. Messaili

The present study was carried out to determine, for the first time, the chemical composition and antibacterial activity of essential oils derived from the aerial parts of three aromatic plants Thymus algeriensis Boiss & Reut, Rosmarinus officinalis L., and Salvia officinalis L. growing under semiarid conditions. The essential oils were chemically analyzed and identified by gas chromatography (GC) and GC/ mass spectrometry (GC/MS) and their antimicrobial activity was individually evaluated against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa using both agar disk diffusion and agar dilution methods. The major constituents of Thymus algeriensis essential oil were identified as camphor (13.62%), 1,8-cineol (6.00%), borneol (5.74%), viridiflorol (4.00%), and linalool (3.93%). For Rosmarinus officinalis essential oil, 48 compounds were characterized, of which the main constituents were camphor (17.09%), Z-β-ocimene (10.88%), isoborneol (9.68%), α-bisabolol (7.89%), and borneol (5.11%). While, Salvia officinalis essential oil was characterized by β-thujone (16.44%), followed by viridiflorol (10.93%), camphor (8.99%), 1,8-cineol (8.11%), trans-caryophyllene (5.85%), and α-humulene (4.69%) as the major components. Notably, results from antibacterial screening indicated that Thymus algeriensis and Salvia officinalis essential oils exhibited a strong inhibitory effect against both Escherichia coli and Staphylococcus aureus compared to Rosmarinus officinalis essential oil. Further, less activity was recorded against Pseudomonas aeruginosa for the three tested essential oils.


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