Enhanced photocatalytic activity and stability of nano-scaled TiO2 co-doped with N and Fe (original) (raw)
Related papers
Synthesis and Photocatalytic Activity of Copper and Nitrogen Co-doped Titanium Dioxide Nanoparticles
Results in Physics
Cu-N co-doped TiO 2 nanoparticles were synthesized using the sol-gel method at different Cu concentrations (0.1, 0.3, and 0.5 wt%). The synthesized nanoparticles were characterized using X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer (FTIR), field emission scanning electron microscopy and energy dispersive X-ray spectrometer (FESEM/EDS), and UV-vis spectrophotometry (UV-vis). The synthesized spherical nanoparticles were grouped into large clusters. Pure TiO 2 nanoparticles exhibited the anatase phase, while Cu-N codoped TiO 2 nanoparticles showed both anatase and rutile phases. In addition, Cu-N co-doped TiO 2 nanoparticles showed higher light absorption than pure TiO 2 nanoparticles, which affected the photocatalytic efficiency. The photocatalytic degradation of methylene blue (MB) was tested under UV and visible light. Under UV light, pure TiO 2 nanoparticles exhibited a maximum photocatalytic efficiency of 88.62% within 90 min. While 0.1 Cu-N codoped TiO 2 nanoparticles tend to be effective in photocatalytic efficiency under visible light, they were able to degrade MB up to 56.33%.
Journal of Materials Science: Materials in Electronics, 2018
The aim of this work was synthesis and investigation of various properties of Co-doped titanium dioxide nanostructures. Synthesis was conducted by the co-precipitation method using cobalt nitrate and titanium isopropoxide as a precursor, followed by thermal treatment at a temperature of 500 °C. The materials were fully characterized using several techniques (X-ray diffraction XRD, SEM, FTIR, TGA/DTA, UV-Vis diffuse reflectance DRS and photoluminescence). However, dopant has no effect on XRD pattern of the host but it can influence on the various characteristics of host such as optical and electrical properties. The scanning electron microscopy was used to detect the morphology of synthesized nanoparticles which sizes changed with the altitude in the doping concentration to 6%. FTIR spectra exhibit broad peaks where anatase phases of TiO 2 demonstrate very sharp UV-Vis band gap results showed the reduction in band gap from from 3.21 eV, for undoped TiO 2 , to 2.74 eV, for Co doped 6% TiO 2. The photocatalytic activity of the samples were studied based on the degradation of methyl orange as a model compound, where the results showed that Co doped 6% TiO 2 a good photocatalytic activity.
Energy Procedia, 2011
Nitrogen-doped TiO 2 nanomaterials were fabricated from hydrogen titanate prepared by hydrothermal method. The starting materials with difference nitrogen sources and concentration were studied. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), BET surface area, Fourier Transform infrared spectrometer (FT-IR) and UV-vis absorption spectra by UV-VIS spectroscopy. The photocatalytic activity was investigated by degradation of methylene blue aquoeus solution under visible light irradiation. The highest photocatalytic activity of nitrogen-doped TiO 2 was gotten from the sample in which 0.5M guanidine carbonate was used as nitrogen source. Compared with pure TiO 2 (from hydrothermal method) and P25-Degussa, the wavelength range of nitrogen-doped TiO 2 was shifted to visible light while pure TiO 2 and P25-Degussa were showed in ultraviolet region.
Materials Today: Proceedings, 2019
The application of heterogeneous photocatalysis is described as an advanced oxidation process (AOP) for the degradation of the diazo reactive dye using immobilized TiO 2 as a photocatalyst. Starting TiO 2 solutions were prepared with and without the addition of polyethylene glycol (PEG) and TiO 2 films were directly deposited on a borosilicate glass substrate using the sol-gel dip-coating method. The surface morphology and the nanoscale roughness of TiO 2 films were studied by means of atomic force microscopy (AFM). Structural properties of TiO 2 were identified by Xray diffraction (XRD). The decomposition behaviour of organic compounds from the gels was investigated using thermal gravimetry (TG) and differential scanning calorimetry (DSC). Photocatalytic activities of TiO 2 films in the process of degradation of the commercial diazo textile dye Congo red (CR), used as a model pollutant, were monitored by means of UV/vis spectrophotometry. The kinetics of the degradation of the CR dye was described with the Langmuir-Hinshelwood (L-H) kinetic model. The addition of PEG to the TiO 2 solution resulted in the changes in the film surface morphology, and affected the ratio of anatase-rutile crystal phases and the photocatalytic activity of TiO 2. The TiO 2 film prepared with PEG is characterized by higher roughness parameters (R a , R max , R q , R z and Z max), a lower amount of the rutile phase of TiO 2 , a higher amount of the anatase phase of TiO 2 and a better photocatalytic activity compared to the TiO 2 film without the addition of PEG.
Materials Today: Proceedings, 2020
In the present study, carbon-doped titanium dioxide (C-TiO 2) nanoparticles (NPs) have been synthesized by utilizing the sol-gel method. Herein, polymer was used as the source for carbon-doping. The synthesized C-TiO 2 was characterized by UV-Diffused Reflectance spectroscopy (UV-DRS). A significant decrease in the band gap of pure TiO 2 was observed upon doping the pure TiO 2 with carbon. The red shift in absorbance values depicted visible-light absorption which was investigated by photocatalytic degradation of the cationic dye, methylene blue (MB). The effectual degradation of the dye depicted the increased photocatalytic activity of the nanoparticles upon carbon-doping.
2021
A facile and room temperature approach to synthesize pure TiO2 and different variants of nirogen and cobalt co-doped TiO2 (CoN-TiO2) catalysts is reported in this study. The successful synthesis and crystalline phase analysis was carried out via X-ray diffraction (XRD) which confirmed anatase phase with tetragonal structure. The spherical morphology, uniform size distribution in the range of 20-40 nm and presence of dopants in final product were validated by scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDS). Diffused reflectance spectroscopy (DRS) is deployed for study of optical properties. A reduction in band gap from 3.2 eV for pure TiO2 nanoparticles to 2.34 eV for the 7 wt.%. doped CoN-TiO2 was observed. The photocatlytic activity of pure TiO2, and CoN-TiO2 nanoparticles was studied against methyl orange.The photocatlytic activity of CoN-TiO2 was almost double as compared to undoped TiO2 which proves these catalysts to be very efficient and poten...
Journal of Technology Innovations in Renewable Energy, 2015
Iron-doped TiO2 nanopowders with different doping amounts have been prepared by co-precipitation method followed by heat treatment. The obtained materials were structurally, morphologically and analytically characterized by X-ray diffraction (XRD), FT-Raman spectroscopy, diffuse reflectance spectroscopy (DRS) and energy dispersive X-ray spectroscopy (EDX) coupled to scanning electron microscopy (SEM). XRD analysis revealed the major presence of the anatasa crystalline phase for iron-doped and undoped TiO2. SEM confirmed particles sizes among the nanometer scale along with XRD data. The presence of iron ions was validated by EDX-SEM. Diffuse reflectance techniques were carried out to validate the shift of the band edge absorption spectrum of doped TiO2 nanoparticles towards the visible region and to confirm the presence of iron atoms in the TiO2 crystal lattice by the resulting variation of the band gap value of the doped materials. Photocatalytic activity of the nanoparticles under UV and visible radiation was evaluated by means of hydroxyl radicals production through indirect estimation using N,N-dimethyl-p-nitrosoaniline (PNDA)photo-discoloration experiments in aqueous dispersion. Samples containing 1.2 and 5.6 weight % Fe exhibited the highest activities in this study for both conditions.
Catalysts
Nitrogen-doped TiO2 has a great potential as a photocatalyst under visible light irradiation with applications in the removal of air and water pollutants, and the treatment of bacterial contaminations. In this study, nitrogen-doped TiO2 nanoparticles were synthesized via the sol–gel method and a post-annealing heat treatment approach. The effects of annealing treatment on the photocatalyst crystalline size and degree of crystallinity were analyzed. Methylene blue dye was used as the model water contaminant for the evaluation of the photoactivity of the synthesized nitrogen-doped TiO2 nanoparticles. The degradation of methylene blue was attributed to three mechanisms, i.e., adsorption, photocatalysis, and direct light photolysis. A kinetic model was developed to distinguish the impact of these three different mechanisms on the removal of contaminants. Adsorption and photocatalysis are heterogeneous processes for removing water organic contaminants. The characterization analysis demon...
Applied catalysis. B, …, 2011
In recent years, significant effort has been focused on the production of visible-light activated photocatalysts such as N-doped TiO 2 for advanced oxidation processes. Thus, this paper describes a facile and simple route to produce N-doped TiO 2 nanoparticles by a modified polymeric precursor method using urea. In addition, the paper describes the characterization and photocatalytic activity evaluation of N-doped TiO 2 nanoparticles. The predominance of the anatase phase and the modification of band-gap energies in N-TiO 2 indicate that the doping process is effective; Raman spectroscopy shows bands related to TiO x N 1−x . The presence of N in higher amounts in the doped nanoparticles confirms the doping process which was also confirmed by X-ray photonelectron spectroscopy (XPS). Unmodified TiO 2 nanoparticles indicate higher UV-C photocatalytic activity, and the N-doped TiO 2 nanoparticles show better visible photocatalytic activity, suggesting a useful way to operate those catalysts under visible light and/or sunlight.
M-doped TiO 2 (M = Ag 2? , Al 3? , Ce 4? , Nb 5? ) with different dopant contents have been prepared by the Pechini method using titanium IV isopropoxide as precursor. The effect of doping concentration on the photocatalytic activity for methyl orange (MO) photodegradation was investigated using UV radiation. The photocatalysts were characterized by surface area, X-ray diffraction and UV-Vis diffuse reflectance spectroscopy. An increase in the photoactivity of TiO 2 nanoparticles was confirmed by MO photocatalytic degradation experiments, when the transition metal ions were incorporated into the semiconductor crystalline lattice, which could be attributed to an increase in the charge separation and reduction of e -/h ? recombination as a function of the substitutional defect generated at very low levels.