Sharif Digital Repository

Copper oxide-titania catalysts with nanocrystalline mesoporous structure were prepared by sol-gel technique using tetra isopropyl ortho titanate (TiPT) as the inorganic precursor and amino-2 ethanol as the swelling agent. Characterization was performed using X-ray diffraction (XRD), fourier transformed infrared spectra (FTIR), scanning electron microscopy (SEM), diffuse reflectance UV-Vis spectroscopy (DRS), and N2 adsorption-desorption measurements. It was found that CuO (0.025-0.1 mol ratio) has some effect on the particle size, surface area, pore-volume, pore-diameter, crystallinity of the particles, and crystalline phase of TiO2 nanocrystalline. The results indicated that 0.1 CuO-TiO2... 

Copper oxide-titania catalysts with nanocrystalline mesoporous structure were prepared by sol-gel technique using tetra isopropyl ortho titanate (TiPT) as the inorganic precursor and amino-2 ethanol as the swelling agent. Characterization was performed using X-ray diffraction (XRD), fourier transformed infrared spectra (FTIR), scanning electron microscopy (SEM), diffuse reflectance UV-Vis spectroscopy (DRS), and N2 adsorption-desorption measurements. It was found that CuO (0.025-0.1 mol ratio) has some effect on the particle size, surface area, pore-volume, pore-diameter, crystallinity of the particles, and crystalline phase of TiO2 nanocrystalline. The results indicated that 0.1 CuO-TiO2... 

The sol-enhanced pulse plating (PP) technique was utilized to deposit the Ni-TiO2/TiO2 multilayers on copper substrates from a Watts bath containing a TiO2 sol, and the obtained coatings were heat treated at various temperatures. The characteristics of coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV-visible spectrophotometry. In order to estimate the wettability of these nanostructured multilayers after exposure to UV light, the contact angle of water droplets were measured, and the photocatalytic (PC) efficiency of the multilayers were analyzed by the degradation of methyl... 

Mordenite (MOR) nanocrystals were synthesized using the hydrothermal method. Sol–gel and deposition methods were utilized to modify the zeolite surface with TiO2 and then AgBr or AgCl particles. Photocatalysts were characterized by using X-ray diffraction, Brunauer–Emmett–Teller (BET), and scanning electron microscopy techniques. Activity was evaluated by photodegradation of Acid Blue 92 as an azo dye. The effect of silver halide deposition on the photocatalytic behavior of the prepared nanocomposites was studied under both ultraviolet (UV) and visible light, and the results were compared. The results showed that AgCl/TiO2/MOR was more active under UV, while with visible source,... 

The photocatalytic activity of mesoporous TiO2 modified by the addition of carbon nanotubes (CNTs) and Cu is reported. Nanocomposites of carbon nanotubes (CNTs) containing varying amounts of Cu were formed by treatment with Cu2+ then reduced to Cu0 using NaBH4 as the reducing agent. The mesoporous TiO2, synthesized by a sol-gel method from titanium isopropoxide, was combined with the CNT/Cu nanocomposites to form the photocatalysts which were characterized by XRD, SEM, TEM, FTIR, XPS and BET surface area analysis. The photocatalytic properties of the mesoporous TiO2 composites were studied by measuring the degradation of methyl orange (MO) which was optimal in the sample containing 20wt% of... 

In this work, the synthesized graphene oxide/TiO2/doxorubicin (GO/TiO2/DOX) composites were loaded into the chitosan/poly(lactic acid) (PLA) solutions to fabricate the electrospun chitosan/PLA/GO/TiO2/DOX nanofibrous scaffolds via electrospinning process. The synthesized composites and nanofibers were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. Three-factor three-level central composite design was used to determine the influence of PLA to chitosan ratio, TiO2/DOX content and GO/TiO2/DOX content on the release of DOX from nanofibrous scaffolds. Drug loading efficiency and drug release behavior from... 

Lithium-Sulfur (Li-S) batteries are considered as one of the promising candidates for next-generation Li batteries in near future. Although, these batteries are suffering from certain drawbacks such as rapid capacity fading during the charge and discharge process due to the dissolution of polysulfides. In this paper, Sulfur/metal oxide (TiO2 and SiO2) yolk-shell structures have been successfully synthesized and utilized to overcome this problem and improve the electrochemical performance of sulfur cahtode material. Prepared materials have been characterized using Scanning Electron Microscopy(SEM), Transmission Electron Microscopy(TEM) and X-ray diffraction (XRD) techniques. The results show... 

Rapid population growth and widespread industrialization are the main contributing factors to the increasing contamination of the world’s diminishing freshwater resources. This work investigates Fe/TiO2 as an efficient and sustainable photocatalyst for treating organic micropollutants in water. The photocatalysts prepared by these mechanochemical methods used a high-energy ball milling technique to manipulate Fe/TiO2’s structural, optical, and catalytic properties for the photo-oxidation of 2,4-Dichlorophenol (2,4-DCP). Doping with iron effectively reduced the band gap of rutile TiO2 from 3 to 2.22 eV. By reducing the ball/powder ratio from 34 to 7, the removal efficiency of 2,4-DCP... 

Titanium dioxide (TiO2) and Cu-doped TiO2 (Cu–TiO2) were synthesized using a sol-gel method and used as nanofillers to prepare CMC-based functional packaging films. The Cu–TiO2 was spherical particles with a size range of 66.1 ± 9.0 nm TiO2 and Cu–TiO2 nanoparticles had good compatibility with CMC and were evenly distributed in the CMC polymer matrix to form a composite film. The TiO2-added film did not show significant antibacterial activity, but the Cu–TiO2-added film exhibited high antibacterial activity against foodborne pathogenic bacteria (L. monocytogenes and E. coli) under visible light. When bananas were packaged with the CMC-based films, the CMC/Cu–TiO2 film effectively delayed the... 

Surface modification of orthopedic implants using titanium dioxide nanotubes and silver nanoparticles (SNs) is a promising approach to prevent bacteria adhesion, biofilm formation, and implant infection. Herein, we utilized a straightforward and all-solution process to prepare silver-decorated TiO2 nanotube arrays with surface density of 10(3) to 10(4) per µm(2). With controlling the synthesis conditions, hexagonal closed-packed nanotubes with opening diameter of 30-100 nm that are decorated with SNs with varying sizes (12-40 nm) were prepared. Various analytical techniques were utilized to characterize the size, morphology, distribution, valance state, surface roughness, and composition of... 

Zeolite-based photocatalysts were prepared by the sol-gel and deposition methods. The photocatalysts were characterised by X-ray diffraction, nitrogen adsorption-desorption isotherms, FTIR spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectrometry. The activity of the prepared photocatalysts was evaluated by the UV-induced degradation of acid blue 92, a textile dye in common use. The effect of various parameters, such as catalyst concentration, initial dye concentration, thiosulphate concentration and pH, on the rate and efficiency of the photocatalytic degradation of acid blue 92 was investigated. The results showed that each parameter influenced the degradation... 

Reduced graphene oxide (RGO) was used to improve the hydrogen sensing properties of Pd and Pt-decorated TiO2 nanoparticles by facile production routes. The TiO2 nanoparticles were synthesized by sol–gel method and coupled on GO sheets via a photoreduction process. The Pd or Pt nanoparticles were decorated on the TiO2/RGO hybrid structures by chemical reduction. X-ray photoelectron spectroscopy demonstrated that GO reduction is done by the TiO2 nanoparticles and Ti–C bonds are formed between the TiO2 and the RGO sheets as well. Gas sensing was studied with different concentrations of hydrogen ranging from 100 to 10,000 ppm at various temperatures. High sensitivity (92%) and fast response time... 

TiO2 nanoparticles (NPs) were synthesized by hydrothermal assisted sol-gel technique. In the next step, as-synthesized NPs were modified by poly ethylene glycol (PEG). Then, folic acid (FA) was conjugated to TiO 2-PEG. Finally, Doxorubicin (Dox) as an anticancer drug was loaded on as-prepared TiO2-PEG-FA nanocarrier. The optimization of TiO 2 and FA concentration and the influence of ultraviolet (UV) irradiation on photocatalytic activity of nanocarrier and Dox loaded carrier were assessed by utilizing the 3-(4,5-dimethylthiazol-2yl)-2,5- diphenyltetrazolium bromide (MTT)-assay method. Results indicated that the effect of NPs on cancer cells killing is dose-dependent, optimized at 1.25 g/L.... 

In this researchC-N-Y tri-doped TiO2 nanopowders were synthesized by the sol-gel method. TheC- N-Y Ti O2 photo-catalyst was prepared using hexamine and yttrium nitrate Hexahydrate as the dopant precursors. Methyl-orange (MO) was used to study the photocatalytic performance of the doped Ti O2 underUVirradiation. The synthesized samples were characterized by x-ray diffraction, x-ray photoelectron spectroscopy,UV-vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, Transmission electron microscopy, Photoluminescence and Field emission scanning electron microscopy. The tri-doped sample with8%N, 0.4% Y and 1.5%Cexhibited enhanced photocatalytic efficiencies. After 100... 

We report a simple and inexpensive synthesis route of TiO2 nanoparticles using electrical arc discharge between titanium electrodes in oxygen bubbled deionized (DI) water followed by heat treatment. The resulting nanoparticles were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD patterns demonstrate formation of TiO2 phase in oxygen bubbled water after heat treatment and dominance of rutile to anatase phase. The size and morphology of TiO2 nanoparticles were studied using different arc currents as a crucial parameter in properties of final... 

In the present paper, the use of a novel carbon paste electrode modified by N,N'(2,3-dihydroxybenzylidene)-1,4-phenylenediamine (DHBPD) and TiO2 nanoparticles prepared by a simple and rapid method for the determination of dopamine (DA) was described. In the first part of the work, cyclic voltammetry was used to investigate the redox properties of this modified electrode at various solution pH values and at various scan rates. A linear segment was found with slope value of about 48 mV/pH in the pH range 2.0 -12.0. The apparent charge transfer rate constant (ks) and transfer coefficient (α) for electron transfer between DHBPD and TiO2 nanoparticles-carbon paste electrode were calculated. In... 

In this work, the effect of addition of ZrO2 to TiO2 and catalyst geometry on photocatalytic properties of the nanocomposite TiO2/ZrO2 was investigated. The traditional use of powdery photocatalyst for the degradation of organic compounds has post-treatment problems which means much higher time and costs. A novel method to minimize these problems is immobilization by insertion onto an inert substrate. Several geometries of TiO2–10%ZrO2 (T-10Z) nano-photocatalysts (powder, fiber, film, and network-shaped) were produced using different templates. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, Brunauer–Emmett–Teller, and diffuse reflectance... 

In this study, the effect of adding 5–12.5 wt% CuO to TiO2 on photocatalytic properties of the nano-composite TiO2/CuO was investigated. The products were characterized by X-ray diffractometer, SEM, Brunauer–Emmett–Teller (BET), and DRS. BET-specific surface area of the TiO2/CuO composites was lower than that of the pure TiO2. Incorporation of CuO into TiO2 shifted absorption spectra to the visible region. As the CuO content increased from 0 to 12.5%, a clear decrease in optical band gap from 2.95 to 2.30 eV was observed. The photocatalytic performance was determined by methyl orange degradation and cyanide photo-oxidation under ultraviolet irradiation. However, the excessive incorporation... 

A novel voltammetric biosensor based on nano-TiO2/nafion/carbon nanoparticles modified glassy carbon electrode (TiO2/N/CNP/GCE) was developed for the determination of dobutamine (DBA). Characterization of the surface morphology and property of TiO2/N/CNP layer was carried out by the scanning electron microscopy and atomic force microscopy. The electrochemical performance of the modified electrode was investigated by means of the cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy techniques. Effective experimental variables, such as the scan rate, pH of the supporting electrolyte, drop size of the casted modifier suspension and accumulation... 

In this paper, we report the preparation of a new composite (TiO2/SiO2/γ-Fe2O3/rGO) with a high photocatalytic efficiency. The properties of the composite were examined by different analyses, including X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), photoluminescence (PL), UV-Visible light diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman, vibrating-sample magnetometer (VSM), and nitrogen gas physisorption (BET) studies. The photocatalytic efficiency of the proposed composite was evaluated by the degradation of methylene blue under UV and visible light, and the results were compared with titanium dioxide (TiO2), where...