scholarly journals Investigation of environmental and therapeutic applications of holmium doped titanium dioxide (Ho-TiO2) nanocatalysts. Kinetic and thermodynamic study of the photocatalytic degradation of Safranin O dye

Author(s):  
F. Akbar Jan ◽  
Wajidullah ◽  
Rahat Ullah ◽  
Salman ◽  
Naimat Ullah ◽  
...  

Abstract Titanium dioxide (TiO2) and Holmium doped Titanium dioxide(Ho-TiO2) nanoparticles (NPs) were synthesized through Sol Gel method. The synthesized NPs were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Photoluminescence spectroscopy. DNA binding, antibacterial, hemolytic and antioxidant assays of the synthesized nanoparticles were also carried out for finding their therapeutic applications. Successful doping of TiO2 with Ho reduced the band gap from 3.10 to 2.88 eV. SEM and XRD analysis showed that both TiO2 and Ho-TiO2 NPs exhibit tetragonal structure and as a result of doping the morphology of the particles improved and agglomeration reduced. PL emission intensity of TiO2 also reduced with doping.The holmium doped TiO2 were used for the first time against the degradation of Safranin O dye, DNA binding study and biocompatibility assay.The degradation of Safranin O dye over both the catalysts followed first order kinetics. The calculated activation energies for the photo degradation of given dye were found to be 51.7 and 35.2 kJ/mol using TiO2 and Ho-TiO2 NPs respectively. At 180 minutes time interval 84 and 87% dye degradation was observed using pure TiO2 and Ho-TiO2 NPs respectively. High percent degradation of dye was found at low concentration (20 ppm) and at optimal dosage (0.035 g) of both the catalysts. The rate of Safranin O dye degradation was found to increase with increase in temperature and pH of the medium. DNA binding study revealed that Ho-TiO2 NPs are more capable of binding to human DNA. Antibacterial activity study showed that Ho-TiO2 NPs were more efficient against both gram-negative and gram-positive bacterial strains as compared to pure TiO2. Hemolysis assay showed that TiO2 and Ho-TiO2 nanoparticles are non-biocompatible.Ho-TiO2 nanoparticles showed higher anti-oxidant activity as compared to bare TiO2.

Nano Futures ◽  
2021 ◽  
Author(s):  
FAZAL Jan ◽  
Wajid Ullah ◽  
Rahat Ullah ◽  
- Salman ◽  
Naimat Ullah ◽  
...  

Abstract Titanium dioxide (TiO2) and Holmium doped Titanium dioxide(Ho-TiO2) nanoparticles (NPs) were synthesized through Sol Gel method. The synthesized NPs were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Photoluminescence spectroscopy. DNA binding, antibacterial, hemolytic and antioxidant assays of the synthesized nanoparticles were also carried out for finding their therapeutic applications. Successful doping of TiO2 with Ho reduced the band gap from 3.10 to 2.88 eV. SEM and XRD analysis showed that both TiO2 and Ho-TiO2 NPs exhibit tetragonal structure and as a result of doping the morphology of the particles improved and agglomeration reduced. PL emission intensity of TiO2 also reduced with doping.The holmium doped TiO2 were used for the first time against the degradation of safranin O dye, DNA binding study and biocompatibility assay.The degradation of Safranin Odye over both the catalysts followed first order kinetics. The calculated activation energies for the photo degradation of given dye were found to be 51.7 and 35.2kJ/mol using TiO2 and Ho-TiO2 NPs respectively. At 180 minutes time interval 84% and 87 % dye degradation was observed using pure TiO2 and Ho-TiO2 NPs respectively. High percent degradation of dye was found at low concentration (20ppm) and at optimal dosage (0.035g) of both the catalysts. The rate of Safranin O dye degradation was found to increase with increase in temperature and pH of the medium. DNA binding study revealed that Ho-TiO2 NPs are more capable of binding to human DNA. Antibacterial activity study showed that Ho-TiO2 NPs were more efficient against both gram-negative and gram-positive bacterial strains as compared to pure TiO2. Hemolysis assay showed that TiO2 and Ho-TiO2 nanoparticles are non-biocompatible.Ho-TiO2 nanoparticles showed higher anti-oxidant activity as compared to bare TiO2.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Mohamad M. Ahmad ◽  
Shehla Mushtaq ◽  
Hassan S. Al Qahtani ◽  
A. Sedky ◽  
Mir Waqas Alam

Metal oxide titanium dioxide (TiO2) nanoparticles were synthesized by using a simple and economical sol-gel method. The prepared nanoparticles were used to evaluate methylene blue dye degradation and as catalysts in the oxidation of benzaldehyde. The crystallite size of the titanium dioxide nanoparticle was 18.3 nm, which was confirmed by X-ray diffraction analysis. The spherical morphology was confirmed by scanning electron microscopy (SEM), and the elemental composition of the nanoparticle was found by energy dispersive X-ray (EDAX) analysis. The anatase form of the nanoparticle was confirmed by the bandgap 3.2 eV, which was measured using UV–DRS analysis. The bond between metal and oxygen was confirmed by the peaks at 485 and 606 cm–1 analyzed by Fourier transform infrared analysis (FTIR). The efficiency of the catalyst in dye degradation was 60.08, 68.38, and 80.89% with respect to 50, 75, and 100 mg catalyst weight. The yield % of benzoic acid was 94%, and the reduction efficiency against 4-nitrophenol was 98.44%.


2019 ◽  
Vol 946 ◽  
pp. 181-185 ◽  
Author(s):  
Sergei N. Fedorov ◽  
Vladimir Yuryevich Bazhin ◽  
Vladimir G. Povarov

Titanium dioxide has a special feature: anatase, to rutile transformation which was considered in our investigations. It is especially important to keep anatase form of titanium dioxide for photocatalytic materials, different ceramics with tribo-chemical properties, self-cleaning coatings and self-sterilizing coatings. For that only one of the titanium dioxide forms is more suitable – anatase, which is more active but not stable, because it transforms to rutile during the time or with the temperature increase loses its activity. Different methods of stabilising anatase have been considered in the paper. Several doping agents have been determined and it was chosen fluorine ion to modify titanium dioxide. Stabilization of anatase is achieved by preparing the reaction mixture by a sol-gel method with hydrofluoric acid. It has shown thermodynamic data, results of experiment, temperatures of anatase to rutile transformation of non-doped and doped titanium dioxide, its X-Ray diffraction and TGA. It is proved that titanium dioxide doped by fluorine ion keeps anatase form till the temperature is more than 1000 °C.


2018 ◽  
Vol 63 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Harish Phattepur ◽  
Gowrishankar Bychapur Siddaiah ◽  
Nagaraju Ganganagappa

A sol-gel method was employed to synthesise pure titanium dioxide (TiO2) and surfactant assisted TiO2 nanoparticles (NPs). The effect of novel surfactant viz., Lauryl lactyl lactate on photocatalytic properties of TiO2 was studied. TiO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis Diffuse Reflectance spectra (DRS), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Thermo gravimetric analysis (TGA), and Brunauer – Emmet - Teller (BET) surface area. Anatase phase of TiO2 was confirmed by X-Ray diffraction pattern and the crystallite size was between 9–19 nm. Addition of surfactant improved the BET surface area, surface defects, while the agglomeration of particles was reduced. DRS results revealed that the addition of surfactant to TiO2 sol induced a red shift of the absorption edge which resulted in the reduction of band gap from 3.23 to 3.21 eV. These physicochemical properties of TiO2 NPs were correlated with photocatalytic degradation of phenol. About 92% of phenol degradation was observed for surfactant assisted TiO2 NPs (SA-TiO2). Salicylic acid and caffeine were also degraded using SA-TiO2 NPs.


2017 ◽  
Vol 7 (3) ◽  
Author(s):  
Pourya Mehdizadeh

In this research, N-doped TiO2 (N/TiO2) nanoparticles have been synthesized by a sol-gel method. N/TiO2 nanoparticle has been coated with Ag metal by photochemical method. Triethylamine, N(CH3CH2)3, have been used as precursors of Nitrogen, titanium tetraiso-propoxide (TTIP), Ti[OCH(CH3)2]4, used as precursors of titanium and Ag(NO3)2 used as precursors of Silver in synthesis of these nanoparticles. The photocatalytic activity has been perused for degradation of Methyl Orange (MO) as model of natural pollutants. Synthesized nanoparticles were analyzed by X-ray diffraction spectroscopy, Fourier transform spectroscopy, scanning electron microscopy, and energy dispersive of X-ray spectroscopy and diffuse-reflectance of Ultraviolet-visible spectroscopy. Results illustrated that under both visible and ultraviolet light, N/TiO2 nanoparticles had medium activity but with coating, the activity in each area efficiently improved. The presence of 1.5% Ag coated on N/TiO2 (with 2:1 mole ratio) resulted to the highest activity under visible and Ultraviolet irradiation in the catalyst.


2016 ◽  
Vol 2 (02) ◽  
pp. 61
Author(s):  
Mukhtar Effendi ◽  
Bilalodin B

<span>Iron (Fe) doped titanium dioxide (TiO<span>2<span>) thin films have been successfully deposited by <span>using spin coating technique. X-ray diffraction (XRD) and Scanning Electron Microscope <span>(SEM) were employed to characterize the microstructure and crystallite morphology of the <span>films. It was indicated that the rutile crystal orientation appears due to increasing annealing <span>temperature of the thin films. Furthermore, increasing annealing temperature of the thin <span>films yielded an increasing of porosity value which is related to the application on gas <span>sensor films.</span></span></span></span></span></span><br /></span></span></span>


2021 ◽  
Vol 33 (12) ◽  
pp. 3139-3144
Author(s):  
Jayaram Mari Selvi ◽  
Mariappan Murugalakshmi ◽  
Ponnusamy Sami

In present work, the Erythrina variegata leaves extract acts as a reducing agent for the green synthesis of titanium dioxide (TiO2) nanoparticles. The characterization of the extracted TiO2 nanoparticles were confirmed by ultraviolet spectral studies (UV-Vis), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDAX) and scanning electron microscopy (SEM). The UV-Vis absorption spectrum exhibited maximum absorbance peak at 317.6 nm,w hich supports the formation of TiO2 nanoparticles. The optical band gap energy value has been determined as 2.35 eV. Further characterization by XRD supports the crystallinity and the incidence of peak at 25.28 ºC corresponds to 101 anatase form. The anatase phase TiO2 sample having tetragonal structure with mean crystalline size was found to be 7.91 nm. Scanning electron microscope image supports the shape of the nanoparticles. These nanoparticles are having effective dye degradation ability with various time intervals. The green synthesized TiO2 nanoparticles exhibits interesting photocatalytic efficacy on methylene blue dye under UV irradiation (using multi-lamp photo reactor) and antibacterial activity against pathogenic organisms like Streptococci, Staphylococci, E. coli and Pseudomonas aeruginosa.


2021 ◽  
Vol 35 (1) ◽  
pp. 151-160
Author(s):  
S. C. Vella Durai ◽  
E. Kumar ◽  
D. Muthuraj

This article explains a novel synthesis for producing titanium dioxide (TiO2) nanoparticles by a sol-gel technique using titanium tetraisopropoxide as a titanium source. The synthesized nanoparticles were analyzed using many measurements like X-ray diffraction (XRD), HRTEM, absorption UV spectroscopy, FTIR, and ac impedance spectroscopy. X-ray peaks were used to calculate the crystallite size and lattice strain by Williamson–Hall method. Crystallite size calculated from x-ray diffraction using the Scherrer equation gives an approximate size and cannot be used for measurements. TiO2 nanoparticles are found to possess a tetragonal structure with a crystalline size around 12 nm. Particle size was confirmed by HRTEM images. The optical studies response for the nanoparticles showed the possible visible absorption peaks for TiO2 nanoparticles are 323 nm. Bandgap energy (Eg) of the TiO2 nanoparticle calculated from UV visible absorption spectra is discussed, and the bandgap is 3.14 eV. FTIR spectra showed vibration bands of the Ti-O network. AC Conductivity properties of TiO2 nanoparticles are studied in the frequency range 1 to 8 MHz at varying temperatures. The conductivity of the TiO2 nanoparticle is found to be constant in the low angular frequency region. Dielectric parameters were analyzed at different temperatures and frequencies.                     KEY WORDS: Conductivity, Dielectric, Nanoparticles, Titanium dioxide, Structural studies   Bull. Chem. Soc. Ethiop. 2021, 35(1), 151-160. DOI: https://dx.doi.org/10.4314/bcse.v35i1.13


2021 ◽  
Vol 891 ◽  
pp. 49-55
Author(s):  
Edgar Clyde R. Lopez ◽  
Nicole Elyse B. Saputil ◽  
Lance A. Loza ◽  
Fiona Fritz G. Camiguing ◽  
Marlon L. Mopon Jr. ◽  
...  

Photoelectrocatalysis has emerged as a promising technology to degrade recalcitrant pollutants such as textile dyes in wastewater completely. Titanium dioxide is typically used as a photocatalyst, but its wide bandgap constrains its use to the use of ultraviolet light. To extend its use to the visible-light region, we doped titanium dioxide nanotubes with iron and sulfur. We used them as a photoelectrode for the photoelectrocatalytic degradation of a model pollutant – phenol red. Response surface methodology using a Box-Behnken design of experiments was used to investigate the effects of initial dye concentration, applied potential, and dopant loading on phenol red degradation kinetics. Statistical analysis showed that our reduced cubic model adequately correlates these parameters. The fastest dye degradation rate was achieved at the optimized conditions: initial phenol red concentration = 5.0326 mg L-1, applied voltage = 29.9686 V, and dopant loading = 1.2244 wt.%. Complete degradation of phenol red may be achieved after 11.77 hours of treatment under the optimized conditions in a batch reactor. Our model's robustness enables it to be used for process modeling and a basis for designing scaled-up photoelectrocatalytic reactors.


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