Influence of ammonia on properties of TiO2 -MgFe2 O4 as high visible-light active photocatalysts for the degradation of Rhodamine B (original) (raw)
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Vietnam Journal of Chemistry, 2018
The influence of ammonia on TiO 2-MgFe 2 O 4 catalysts synthesized via a hydrolysis and co-precipitation, followed by calcination at 500 o C, was studied. Two different catalysts, TiO 2-MgFe 2 O 4 (Am) and TiO 2-MgFe 2 O 4 (W), were prepared using Ti-precursors, which were synthesized by the hydrolysis of Ti-butoxide with and without ammonia. The resulting TiO 2-MgFe 2 O 4 catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area measurements, X-ray diffraction, and UV-vis diffuse reflectance techniques. It was revealed that strong electronic coupling exists between the TiO 2 and MgFe 2 O 4 components within the TiO 2-MgFe 2 O 4 catalysts. Photocatalytic activity toward Rhodamine B (RhB) was investigated in aqueous solution under visible light irradiation. TiO 2-MgFe 2 O 4 (W) was found to be an effective catalyst and had several advantages over TiO 2-MgFe 2 O 4 (Am). These results clearly highlight that ammonia had a significant influence on the photocatalytic activity of the TiO 2-MgFe 2 O 4 catalysts. Therefore, the results reported herein indicate that TiO 2-MgFe 2 O 4 is a green, low-cost, and highly efficient photocatalyst for environmental remediation.
Applied Catalysis B-environmental, 2009
C-, S-, N-, and Fe-doped TiO2 photocatalysts were synthesized by a facile sol–gel method. The structure and properties of catalysts were characterized by N2 desorption–adsorption, X-ray diffraction (XRD), UV–vis spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results revealed that the surface area of the multi-doped TiO2 was significantly increased and the crystallite size was smaller than the pure TiO2 obtained by
Scientific Reports, 2023
The current investigation deals with the simple and ecological synthesis of CaO, MgO, CaTiO 3, and MgTiO 3 for the photocatalytic dilapidation of rhodamine B dye. CaO was procured from chicken eggshell waste by calcination process, while MgO was produced by solution combustion method using urea as a fuel source. Furthermore, CaTiO 3 and MgTiO 3 were synthesized through an easy and simple solid-state method by mixing thoroughly the synthesized CaO or MgO with TiO 2 before calcination at 900 °C. XRD and EDX investigations confirmed the phase formation of the materials. Moreover, FTIR spectra revealed the existence of Ca-Ti-O, Mg-Ti-O, and Ti-O which resembles the chemical composition of the proposed materials. SEM micrographs revealed that the surface of CaTiO 3 is rougher with relatively dispersed particles compared to MgTiO 3 , reflecting a higher surface area of CaTiO 3. Diffuse reflectance spectroscopy investigations indicated that the synthesized materials can act as photocatalysts under UV illumination. Accordingly, CaO and CaTiO 3 effectively degraded rhodamine B dye within 120 min with a photodegradation activity of 63% and 72%, respectively. In contrast, the photocatalytic degradation activity of MgO and MgTiO 3 was much lower, since only 21.39 and 29.44% of the dye were degraded, respectively after 120 min of irradiation. Furtheremore, the photocatalytic activity of the mixture from both Ca and Mg titanates was 64.63%. These findings might be valuable for designing potential and affordable photocatalysts for wastewater purification. Despite being one of the most harmful pollutants, dyes are widely used in the fabric, food, plastic, chemical, and tabloid industries. Their discharge into the aquatic environment has a serious impact on living organisms 1,2. Color reduces sunlight penetration through water, resulting in decreased photosynthetic activity and decreased biota development. In addition, dyes tend to bind metal ions, resulting in micro toxicity in fish and other living things 1,3. Normally, dyes are barely biodegradable and challenging to be eliminated by conventional approaches. In this context, rhodamine B (RhB) which belongs to the xanthene family, is a highly stable cationic dye due to its rigid heterocyclic structure 4. Indeed, the high stability of RhB dye is beneficial for different industrial applications, however, makes its degradation not simple and challenging 5-7. As a result, providing efficient, environmentally friendly, and cost-effective solutions for the breakdown of such contaminants is critical for the long-term viability of green habitats. This has resulted in a diverse range of techniques being employed to extract dyes from
Visible light catalysis of rhodamine B using nanostructured Fe2O3, TiO2 and TiO2/Fe2O3 thin films
Journal of Photochemistry and Photobiology B: Biology, 2014
composite films are deposited using spray pyrolysis method onto glass and FTO coated substrates. The structural, morphological, optical and photocatalytic properties of Fe 2 O 3 , TiO 2 and TiO 2 /Fe 2 O 3 thin films are studied. XRD analysis confirms that films are polycrystalline with rhombohedral and tetragonal crystal structures for Fe 2 O 3 and TiO 2 respectively. The photocatalytic activity was tested for the degradation of Rhrodamine B (Rh B) in aqueous medium. The rate constant (Àk) was evaluated as a function of the initial concentration of species. Substantial reduction in concentrations of organic species was observed from COD and TOC analysis. Photocatalytic degradation effect is relatively higher in case of the TiO 2 /Fe 2 O 3 than TiO 2 and Fe 2 O 3 thin film photoelectrodes in the degradation of Rh B and 98% removal efficiency of Rh B is obtained after 20 min. The photocatalytic experimental results indicate that TiO 2 /a-Fe 2 O 3 photoelectrode is promising material for removing of water pollutants.
Turkish Journal of Chemistry, 2007
Nanosize crystalline TiO2 and SiO2/TiO2 mixed oxide particles as a photocatalyst for rhodamine B dye (RB) degradation in aqueous media were synthesized by a hydrothermal process at 200 • C. They were characterized using XRD, SEM, FT-IR, UV/VIS and BET analysis. The effects of silica content on the crystallinity and photocatalytic activity of TiO2 were investigated. Photocatalytic activity of the nano-TiO2 was compared with that of SiO2/TiO2 mixed oxides at the same conditions for degradation of RB, and mixed oxide catalysts showed more effective catalytic activity than the TiO2. The results revealed that photodegradation of RB proceeds by pseudo-first-order reaction kinetics where the rate constant, k, for degradation of 30 mg/L RB using the catalyst with 0.05 SiO2/TiO2 mole ratio is 0.133 min −1 .
2012
Magnetic nanoparticles of TiO 2-(x)NiFe 2 O 4 with x = 0.01, 0.1, and 0.3 have been synthesized by mixture of titanium isopropoxide (TIP) and nitric metal as precursors. The particles were characterized by XRD, SEM-EDX, and VSM. XRD pattern show the peaks at 2 = 25.3°, 38.4°and 47.9°which are referred as anatase phase of TiO 2. Meanwhile NiFe 2 O 4 phase was observed clearly for x = 0.3. The present of NiFe 2 O 4 can prevent the transformation of TiO 2 from anatase to rutile when the calcination temperature increased. Microstructure analyses by SEM show the homogeneous form and size of particles. The magnetic properties analysis by VSM indicates that TiO 2-NiFe 2 O 4 is paramagnetic behavior. TiO 2 doped NiFe 2 O 4 has higher photocatalytic activity than TiO 2 synthesized for degradation of Rhodamine B in aqueous solution under solar light irradiation.
PHOTODEGRADATION OF RHODAMINE 6G IN PRESENCE OF Ag/TiO2 PHOTOCATALYST
SIMI 2018
In this work, the commercial titanium dioxide P25 was doped with silver ions via wet impregnation method, in order to improve its catalytic activity. It is already well established that Ag ions can improve the activity of a catalyst and diminish the electron-holes recombination rate. The catalysts obtained by samples calcination at 450 and 600 o C were tested as heterogeneous photocatalysts in the degradation of Rhodamine 6G, a very stable fluorescent dye. The obtained results confirm the improvement of the catalytic activity, compared to TiO2 P25. Despite the degradation efficiency is not very high, it is worthy to note that the Ag doped catalyst has a higher activity compared to commercial P25. Thus, we can conclude that modifying the catalyst surface leads to an improvement of the properties, probably by forming an intermediate energy level between the valence and conduction bands of TiO2.
Scientific Reports
nowadays, there is a growing concern about the environmental impacts of colored wastewater. thus, the present work aims the synthesis, characterization and determination of photocatalytic activity of iron oxide (fe 2 o 3) nanocatalyst, evaluating the effect of hybridization with titanium (TiNPs-Fe 2 o 3) and silver (AgNPs-Fe 2 o 3) nanoparticles, on the degradation of Rhodamine B dye (RhB). nanocatalysts were characterized by XRD, SeM, teM, ftiR, n 2 porosimetry (Bet/BJH method), zeta potential and DRS. photocatalytic tests were performed in a slurry reactor, with the nanocatalyst in suspension, using RhB as a target molecule, under ultraviolet (UV) and visible radiation. therefore, the photocatalytic activity of the nanocatalysts (non-doped and hybridized) was evaluated in these ideal conditions, where the AgNPs-Fe 2 o 3 sample showed the best photocatalytic activity with a degradation of 94.1% (k = 0.0222 min −1 , under UV) and 58.36% (k = 0.007 min −1 , under visible), while under the same conditions, the tio 2-P25 commercial catalyst showed a degradation of 61.5% (k = 0.0078 min −1) and 44.5% (k = 0.0044 min −1), respectively. According with the ideal conditions determined, reusability of the AgNPs-Fe 2 o 3 nanocatalyst was measured, showing a short reduction (about 8%) of its photocatalytic activity after 5 cycles. Thus, the Fe 2 o 3 nanocatalyst can be considered a promising catalyst in the heterogeneous photocatalysis for application in the degradation of organic dyes in aqueous solution.
Photocatalytic Decomposition of Rhodamine-B Using Scandium and Silver-Modified TiO2 Powders
Advanced Materials Research, 2014
Semiconductor-mediated photocatalytic oxidation is an interesting method for water decontamination and a specially modified TiO 2 is said to be a promising material. This study verified that the synthesis of 1wt%Ag modified-Sc 0.01 Ti 0.99 O 1.995 powder samples prepared by Polymeric Precursor Method is capable of forming a mixture of anatase-rutile phase with high photocatalytic performance. This kind of material is found to have a lower bandgap compared to the TiO 2 -anatase commercial powders, which can be associated to an innovative hybrid modification. The simultaneous insertion of scandium in order to generate a p-type semiconductor and a metallic silver nanophase acting as an electron trapper demonstrated being capable of enhancing the degradation of rhodamine B compared to the commercial TiO 2 . In spite of the different thermal treatments or phase amounts, the hybrid modified powder samples showed higher photocatalytic activity than the commercial ones.
Photocatalytic Degradation of Rhodamine B in Heterogeneous and Homogeneous Systems
Hungarian Journal of Industry and Chemistry, 2021
This study focuses on the photocatalytic degradation of Rhodamine B (RhB) in heterogeneous and homogeneous photo-Fenton reactions. In the heterogeneous system, iron(II) doped copper ferrite CuII(x)FeII(1-x)FeIII2O4 nanoparticles (NPs) prepared in our previous work were employed as potential catalysts. The photodegradation of RhB was carried out in a quartz cuvette located in a diode array spectrometer. The experimental conditions such as pH, NPs dosage and H2O2 dosage with regard to the photocatalytic degradation of RhB were optimized to be 7.5, 500 mg/L and 8.9x10-2 mol/L, respectively. In addition, visible light-induced photodegradation of RhB was also carried out by using \ch{H2O2} over a wide pH range in the absence of heterogeneous photocatalysts. It was observed that the reaction rate significantly increased above pH 10, resulting in a faster rate of degradation of RhB, which may be attributed to the deprotonation of hydrogen peroxide. Furthermore, the potential antibacterial ...