Degradation Efficiency Of TiO2 Research Articles

A novel SiP/TiO2 S-scheme heterojunction photocatalyst for efficient degradation of norfloxacin

Photocatalysis is considered to be an effective approach for eliminating intractable organic pollutants in wastewater. However, its inefficiency is attributed to the slow transport and quick complexation of photogenerated carriers. Herein, we proposed a novel SiP/TiO2 S-scheme heterojunction photocatalyst synthesized by hydrothermal method. And this photocatalyst was firstly used for the efficient degradation of norfloxacin, degrading 90.89% of norfloxacin (NOR) in 100 min which was 3 times higher than the degradation efficiency of TiO2 (29.98%). Results from spectral analysis and density functional theory (DFT) calculations confirm that an internal electric field (IEF) exists in the SiP/TiO2 heterojunction. This IEF is advantageous for transporting and separating photogenerated carriers. Unlike conventional powder photocatalysts, this photocatalyst grown on conductive glass is not only simple to recycle, but also prevents environmental contamination. This research opens up new options for designing and applying heterojunction catalysts.

The Rutile Phase of TiO2/Graphene Films: Sol–Gel Method, Phase Transition, Photocatalytic Properties

TiO2 materials are of great interest in different applications because of the controllable preparation of different structures. In this paper, the TiO2 and TiO2/graphene films with different phase structure and inserted graphene layer between Cu substrate and TiO2 film were prepared by sol–gel method at different annealing temperatures, and then used as catalysts for photo-degradation of methylene blue (MB) dye solution under ultraviolet irradiation using 15 W of ultraviolet lamp. The effects of annealing temperature and graphene layer on the phase structure, morphology, chemical composition, binding energy level, and photocatalytic performance of TiO2 films were studied in details. XRD results reveal that the anatase phase of TiO2 films transfers to rutile phase with the increase in annealing temperature, and the introducing of graphene film layer can accelerate the phase transformation of anatase to rutile and improve the crystallization quality of TiO2 films. It is found that the MB degradation efficiency of TiO2 and TiO2/graphene films is enhanced with the increasing annealed temperature, which shows that the existence of rutile phase, well crystalline quality and the better dispersion of the TiO2 particles are helpful in photocatalytic behavior. In addition, compared to the rutile phase TiO2 film, the rutile phase TiO2/graphene films at annealed temperatures of 900 °C exhibit much higher photocatalytic activity due to the introduction of graphene films.

STUDIES OF SEM, EDS, XRD, UV-Vis, PCTA (2 DYES -8TIMININGUV) IN TZZ: TiO2/ ZnO WITH (1:2) RATIO

Carbon spheres as template with hydrothermal method we prepared TiO2,ZnO, and TiO2/ ZnO composite hollow spheres of 1:2. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), EDS and UV-Vis. Photo degradation activity of composite hollow spheres is studied for two dyes Methylene Blue(MB), and RhodamineB(RhB)at different time intervals (0-270min) under UV Lamp(54 watts).The results are systematically analysed and reported at the end ,the degradation efficiency of TiO2/ ZnO (1;2) hollow spheres is about 90% within 270 min.

Preparation of Highly Stable and Effective N-Doped TiO2@SiO2 Aerogel Catalyst for Degradation of Organic Pollutants by Visible Light Catalysis

To obtain high stable and effective TiO2 photocatalyst, nano-N-doped TiO2@SiO2 (TiO2−xNx@SiO2, 0 ≤ x ≤ 2) composite aerogels were synthesized by the sol-gel method combined with supercritical drying and direct oxidation process. The adsorption/photocatalytic degradation efficiency of TiO2−xNx@SiO2 aerogels was evaluated by the degradation of RhB in aqueous solution under visible light irradiation. The physiochemical properties of the aerogels were examined by XRD, FT-IR, TEM, SEM, TG/DTA, and BET methods. It was found that the specific surface areas of all TiO2−xNx@SiO2 samples exceeded 700 m2/g and exhibited a honeycomb porous structure with fine particulate morphology. Photocatalytic activity tests show that the 500-TiO2@SiO2 composite aerogel exhibits the best adsorption/photocatalytic degradation rate for RhB, which obtained about 80% of the degradation rate in 30 min under visible light and over 95% after 120 min. On the one hand, the SiO2 aerogels can significantly inhibit the phase transition of TiO2, and the nano TiO2 can be highly dispersed in the SiO2 aerogels; On the other hand, if the oxidation temperature is selected properly, the N-doped TiO2−xNx@SiO2 aerogel can be obtained by simple TiN@SiO2 aerogel oxidation.

Spectroscopic analyses of the photocatalytic behavior of nano titanium dioxide

Nano titanium dioxide TiO2 was synthesized using hydrolysis method then subjected to several characterizations. XRD revealed that the as-prepared sample is pure anatase phase and after calcinations at 500°C for 3h the crystallinity has increased. The crystallite size calculated by Debye–Scherrer’s formula is 8nm. The HRTEM image shows an average size of about 9nm, which is close to the XRD calculation from Scherrer’s formula. PM3 semiempirical quantum mechanical calculations were conducted to present the electronic as well as thermal properties for TiO2. FTIR spectra between 800 and 400cm−1 are the verification for the lattice vibrations of anatase TiO2. The photo catalytic degradation of methylene blue (MB) was tested by the prepared nano TiO2. Results indicate that, the maximum degradation efficiency reached 94.4% after 120min of UV irradiation. This increase in the degradation efficiency of TiO2 could be attributed to the reduction in particle size that enhanced the crystallinity as a result of heat treatment.