Here, the effect of lightly Niobium doped TiO2 layer on the performance of perovskite solar cells has been studied by using solar cell capacitance simulator (SCAPS). N addition, the effects of Niobium concentration, buffer film thickness and operating temperature on the performance of the perovskite solar cell are investigated. For doping level of 3. 0 mol% into the TiO2 layer, cell efficiency of 18. 26% with Voc of 0. 96 V, Jsc of 22. 45 mA/ cm 2 and FF of 84. 25% has been achieved. Calculations show that thickness widening of Nb-doped TiO2 layer would decrease the efficiency and Voc of the cells. Increase in operating temperature from 300 k to 400 k would weaken the performance of the perovskite solar cell with both pure and Nb-doped TiO2 layers. However, the cell with Nb-doped TiO2 layer shows higher stability than the cell with pure TiO2 buffer at higher temperatures.

This paper describes the photocatalytic degradation of Reactive Blue 19 (RB-19) and Reactive Red 76 (RR-76) dyes pollutant in the industrial wastewater using TiO2, C-doped TiO2 (C-TiO2), S-doped TiO2 (S-TiO2) and C, S co-doped TiO2 (C, S-TiO2) nanoparticles as photocatalysts, which were synthesized via sol-gel process. The prepared photocatalysts were characterized by scanning electron microscopy (SEM), X-Ray diffraction (XRD), Fourier transformer infra-red spectroscopy (FTIR), Energy dispersive spectroscopy (EDAX) and ultraviolet-visible absorption spectroscopy (UV-Vis). The dyes degradation was investigated under several experimental parameters such as pH, catalyst load, dye concentration, shaking speed, irradiation time and catalyst recovery. The photocatalytic dose was found to be 1.6 g/L and the efficiency of RB-19 and RR-76 photocatalytic degradation attained 100 % after 1 h irradiation time under visible light. The chemical oxygen demand (COD) values were determined for wastewater and treated wastewater. Toxicity and biological activity of the treated and untreated wastewater on marine aquatic organisms rotifer, artemia and Vibrio parahaemolyticus were investigated.

Background and purpose: Sonocatalytic process as an advanced oxidation process is considered for degradation of pollutants in aqueous solution. The aim of this study was to increase the removal of dye by doping of TiO2 with non-metal element such as nitrogen. Materials and methods: Un-doped and N-doped TiO2 nano-particles with different nitrogen contents were synthesized by a simple sol– gel method in laboratory. X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray analysis (EDX), and UV– visible diffuse reflectance spectra (UV-vis DRS) were used for characterization of the synthesized nanoparticles. The sonocatalytic activity of synthesized nanoparticles was evaluated by investigating degradation of reactive blue 29 under ultrasonic radiation and the effects of nitrogen doping content, different initial pH of solution, and dye concentration. Results: The study showed that both un-doped and doped nano-particles were in nano-sized that tend to agglomerate. By using different nano-particles, the highest sonocatalytic activity was achieved by 0. 6 N-doped TiO2 with 58 % after 90 min of ultrasonic irradiation. Effect of initial pH of aqueous solution showed that the sonocatalytic activity decreased by increase in initial pH. Conclusion: Sonocatalysis using N-doped TiO2 was found to be an effective method for degradation of textile dyes. The high sonocatalytic activity could be attributed to the band gap narrowing and anatase phase in TiO2 nanoparticles. Sonocatalytic degradation followed the Langmuir– Hinshelwood kinetic model (R2 = 0. 98) with a rate constant of 0. 01 mg L− 1 min− 1.

The aim of the present study is to synthesize and characterize Fe-doped TiO2 nanoparticles prepared by a molten salt method using a solid mixture of TiO2 powder and FeCl3 precursor. As far as this study is concerned, this is the simplest method that has been reported so far for the synthesis of Fe-doped TiO2 nanoparticles. Pure TiO2 nanoparticles and 0. 5, 1 and 3 wt% Fe-doped TiO2 samples were prepared. The prepared nanoparticles were characterized by UV-Vis diffusion reflection spectroscopy (DRS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Energy-dispersive X-ray spectroscopy (EDX). SEM and XRD analysis of the samples indicated the presence of anatase spherical-shaped TiO2 particles. The results of EDX study confirmed the presence of Fe in all samples. According to DRS results, the band gap energy of Fe doped TiO2 nanoparticles decreased with increasing Fe concentration from 3. 1 eV for pure TiO2 to 3. 0-2. 80 eV for Fe-doped TiO2. The photocatalytic activity was also checked. It was found that, the photocatalytic activity of Fe-doped nanoparticles was higher than that of the pure TiO2. The maximum degradation activity of 69% was obtained at the Fe doping content of 0. 5 wt%.

Background & Aim: Antibiotics are stable compounds with low biodegradability that are generally not removable by conventional wastewater treatment processes. The aim of this study was to investigate the ability of Fe-doped TiO2@Fe3O4 magnetic nanoparticles in the presence of ultraviolet irradiation to photocatalytic removal of ciprofloxacin from aqueous solutions. Methods: The sol-gel method was used for the synthesis of Fe-doped TiO2@Fe3O4 nanoparticles and the physical and chemical properties of the catalyst were investigated by SEM, EDX, XRD, VSM and DRS analyzes. Then, the effect of different parameters including pH (3-9), initial concentration of ciprofloxacin (25-75 mg/l) and catalyst dose (0. 6 to 0. 2 g/l) at different times in photocatalytic elimination of ciprofloxacin were studied. Results: The results showed that the highest removal efficiency 99. 1 % and reaction rate constant of ciprofloxacin the presence of 15-watt UVC radiation was obtained at pH 9, initial concentration of 25 mg/l, catalyst dose of 0. 6 g/l and contact time of 60 min, respectively. The stability of nanoparticles after 5 reuses had a good removal rate. Conclusion: Due to the appropriate removal efficiency of ciprofloxacin by the integrated system Fe-doped TiO2@Fe3O4 + UVC, the application of this process in water and wastewater treatment processes is recommended.

In this study, different samples of Niobium and Vanadium co-doped titania thin films (5-10-15 mol% Nb and 5-10-15 mol% V) were prepared via sol−gel dip coating method, using Niobium chloride as Niobium precursor, ammonium metavanadate as vanadium precursor, and titanium (IV) butoxide (TBT) as titanium precursor. The effects of doping amount on the structural, optical, and photo-catalytic properties of formed thin films have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis absorption and transmission electron microscopy (TEM). XRD patterns showed a decrease in peak intensities of the anatase crystalline phase by increasing the Nb/V dopant and doping inhibition effect on the grain growth, and revealed that all samples contained only anatase phase (T=475oC). The photo-catalytic activity of the thin film was measured on degradation rate of methylene blue (MB) solution under UV irradiation.Highest photo-catalytic activity of doped TiO2 thin films were measured in the TiO2–5 mol% Nb-15 mol% V sample (TNV4). Small granular crystallites of 10-15 nm 2D diameter were observed in electron microscope micrographs.

In this study V doped TiO2 thin film deposited on glass substrate using a sol-gel dip coating method was investigated. X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectrophotometer were used to investigate the film properties. In addition, the photo-catalytic properties of films were evaluated with methylene blue degradation under UV irradiation. The results indicated that V doping has a significant effect on the absorption edge and photo-catalytic properties of TiO2 thin film.