Methyl orange degradation using nano-LaMnO 3 as a green catalyst under the mild conditions ARTICLE INFO (original) (raw)
Related papers
Methyl orange degradation over nano-LaMnO3 as a green catalyst under the mild conditions
Nanochemistry Research, 2019
This study was conducted to investigate the use of cubic LaMnO3 nano-perovskite as a green catalyst for the degradation of an aqueous solution of methyl orange under different conditions. Nanoscale cubic lanthanum manganite with the particle size of ~20 nm was successfully synthesized via citrate sol-gel method. The sample was characterized using the FT-IR and UV-Vis spectroscopy, XRD, SEM, and TEM analysis. The particle size of catalyst was calculated by Scherer equation using data of XRD analysis. The calculations along with an analysis of SEM and TEM confirm the formation of nanosized perovskite phase. The behavior of this nanocatalyst for degradation of an aqueous solution of methyl orange was investigated at wavelengths of 300-700 nm. The effects of the type and different amounts of acid, the absorbent content, pH, and temperature were studied for obtaining the optimal conditions of degradation. The prepared sample shows a suitable activity for the methyl orange degradation under dark (~90%) condition. The solar catalytic degradation is faster and goes up to about 100% after 60 min, indicating a different reaction pathway with less activation energy. Pre-visible-light degradation is the basis of catalytic activity of lanthanum manganite. A parallel photocatalytic reaction, however, is an almost simpler way to destroy the azo dyes over LaMnO3 nanoperovskite, which makes the LaMnO3 as a proper photocatalyst for degradation.
Asian Journal of Applied Chemistry Research
The Photocatalytic performance of the Calcium doped lanthanum manganite nanocomposite for photodegradation of Methylene Blue(MB) dye as an Organic water pollutant,was evaluated over visible light irradiation, at a pH of 4, at constant dose for several hours. The result showed La0.75Ca0.25MnO3 having Perovskite structure shows high degree of catalytic efficiency of 69% within 100 min illumination time, for the removal of Methylene Blue organic dye from its aqueous solution. The sample powder(LCMO) was prepared through sol-gel technique and was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Inductively coupled plasma- atomic emission spectroscopy (ICP-AES), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and UV-Vis spectroscopy (UV-Vis). The XRD data revealed the formation of single phase crystallinity.SEM images shows that the micro sized La0.75Ca0.25MnO3 powder has nanocrystalline structure with average diame...
Solar photodegradation of methylene blue by LaMnO3 nanorods as a heterogeneous catalyst
2011
Semiconductor photocatalysis has proved to be an efficient method for decolorization and degradation of pollutants. The potential of the prepared photocatalyst in degradation of methylene blue (MB) dye under sunlight irradiation was studied. Characterization of LaMnO 3 nanorods of prepared sample was studied using X-ray powder diffraction (XRD), TG/DTA, SEM, TEM and BET methods. The influence of experimental parameters on the dye photodegradation process was studied and it was observed that photo reactivity of photocatalyst (LaMnO 3) varied with the amount of catalyst, initial dye concentration, pH of the dye solution, H 2 O 2 oxidant. The optimal experimental conditions were determined as follow: catalyst amount; 0.16gm/L, concentration of the dye solution; 10 ppm, pH of solution; 9.3 and 6% H 2 O 2 solution under these optimum conditions, the obtained degradation efficiency for MB dye was 100 %. The reusability of the intended catalyst was also investigated.
Desalination and Water Treatment, 2013
La 0.5 Ca 0.5 CoO 3 perovskite-type oxide is prepared by sol-gel method. The physical and chemical properties of La 0.5 Ca 0.5 CoO 3 were characterized by differential thermal analysis (DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) method and IR techniques. The photocatalytic activity of the sample is evaluated by photocatalytic removal of Congo Red (CR) dye under UV light irradiation. The results of XRD and BET indicate that the perovskite-type oxide (LCCO) have a good crystal phase at 650 and 750˚C with large specific surface area. The DTA, XRD, TEM, SEM, and EDX data revealed that LCCO nanoparticles are prepared successfully via sol-gel modified pechini method. The result showed that the degradation efficiency of CR by LCCO is excellent under UV light irradiation under our experiment condition.
Environmental Challenges, 2021
Lanthanum cerate (La2Ce2O7), a perovskite nanomaterial, has been synthesized by using the gel combustion method to remove carcinogenic and neurotoxic dye FD&C Yellow 5 from its aqueous solution and the same has been also explored to investigate the photocatalytic behavior towards the degradation of food dye. The synthesized material has been extensively characterized using various techniques such as XRD, FT-IR, SEM, BET surface area and through pHZPC. The effect of various operational parameters like solution pH, temperature, and initial dye concentration were investigated to explore the optimum dye removal percentage. To gain the mechanistic perceptive of the dye removal process, various kinetic models were used. Pseudo-second order kinetic model was found to be well suited in describing the sorption system. The intra-particle diffusion model suggested that the film diffusion process controls the overall rate of the dye and perovskite interaction process. Further, equilibrium data interpretation was appraised through various isotherm models and adsorption data found to be consistent with the Freundlich model suggesting multilayer coverage of dye species over the surface of perovskite particles and maximum adsorption capacity was evaluated as 133.3 mg/g at 323 K. Thermodynamic parametric investigation indicated that the dye adsorption process was feasible, spontaneous and endothermic. The activation energy of the adsorbate-adsorbent interaction process was found to be 5.26 kJ/mol, suggesting a physisorption mechanism governs the adsorption process. Photocatalytic efficiency of the perovskite was also scrutinized for dye concentrations 10, 25 and 50 mg/L and dye degradation of 89%, 75% and 69% was observed for each tested concentrations, respectively.
Journal of Saudi Chemical Society, 2015
Visible light induced semiconductor photocatalysis has received a great attention in recent years due to the contamination of water bodies. In the present study, we have reported the photo catalytic degradation of a toxic organic dye, malachite green using a ZnO doped Dy 2 O 3 photo catalyst under visible light irradiation. The nanocrystalline photocatalyst was prepared by a precipitation method employing the respective nitrates and sodium carbonate as precursors and were characterized by FT-IR, XRD, UV-Vis DRS, FE-SEM and AFM analysis. The experimental results proved that the prepared photo catalysts were crystalline, nanosized and highly active in the visible region. UV-Vis DRS results suggested that the band gap was 3.1 eV for the prepared photo catalyst. The photodegradation efficiency of malachite green was analysed by various experimental parameters namely pH, catalyst dosage, variation of substrate concentration and effect of electrolyte addition. The photo degradation process followed a pseudo first order kinetics and was continuously monitored by UV-Visible spectrophotometer. The degradation of malachite green was above 99% within 1 h of visible light irradiation employing the doped photocatalyst, whereas pristine metal oxide possessed only 67% and pristine lanthanide oxide possessed activity which was only due to photolysis. A plausible mechanism for the generation of OH radicals and the pathway for MG dye degradation has been proposed in this study. The experimental results clearly show that nanocrystalline semiconductor doped lanthanide oxides are highly active under visible light irradiations and may find wider applications in environmental remediation technologies.
2012
In this study PbZrO 3 was prepared as a matrix by the sol-gel process and is characterized by XRD and SEM techniques. The particle size of the synthesized nanocomposite is evaluated about 43 nm. The Lead Zirconate is then doped with Ce 3+ /TiO 2 in different ratios. Nanocomposites are added in the reaction in a photoreactor with a pollutant (an Azo dye) and as a result the degradation percentage is obtained. The degradation was studied by monitoring the change in substrate concentration employing UV spectroscopic analysis technique. Kinetic studies on these nanocomposites are carried out based on the related models and the reaction order is evaluated. Finally, Surface adsorption of the pollutants on the nanocomposite surface is measured through IR technique.
Preparation of Perovskite Nanocomposites and Photochemical Degradation Kinetics of Acid Yellow 199
In this study PbZrO 3 was prepared as a matrix by the sol-gel process and is characterized by XRD and SEM techniques. The particle size of the synthesized nanocomposite is evaluated about 43 nm. The Lead Zirconate is then doped with Ce 3+ /TiO 2 in different ratios. Nanocomposites are added in the reaction in a photoreactor with a pollutant (an Azo dye) and as a result the degradation percentage is obtained. The degradation was studied by monitoring the change in substrate concentration employing UV spectroscopic analysis technique. Kinetic studies on these nanocomposites are carried out based on the related models and the reaction order is evaluated. Finally, Surface adsorption of the pollutants on the nanocomposite surface is measured through IR technique.
Photocatalytic activity of MnTiO3 perovskite nanodiscs for the removal of organic pollutants
Heliyon, 2021
MTO nanodiscs synthesized using the hydrothermal approach were explored for the photocatalytic removal of methylene blue (MB), rhodamine B (RhB), congo red (CR), and methyl orange (MO). The disc-like structures of ~16 nm thick and ~291 nm average diameter of stoichiometric MTO were rhombohedral in nature. The MTO nanodiscs delivered stable and recyclable photocatalytic activity under Xe lamp irradiation. The kinetic studies showed the 89.7, 80.4, 79.4, and 79.4 % degradation of MB, RhB, MO, and CR at the rate constants of 0.011(±0.001), 0.006(±0.001), 0.007(±0.0007), and 0.009 (±0.0001) min−1, respectively, after the 180 min of irradiation. The substantial function of photogenerated holes and hydroxide radicals pertaining to the dye removal phenomena is confirmed by radical scavenger trapping studies. Overall, the present studies provide a way to develop pristine and heterostructure perovskite for photocatalysts degradation of various organic wastes.
Journal of Molecular Liquids, 2021
Pristine LaCrO 3 and Co, Fe co-doped La 1-x Co x Cr 1-y Fe y O 3 (x, y = 0.24) perovskite nanoparticles was prepared via micro-emulsion method and the La 1-x Co x Cr 1− yFeyO 3 composite was prepared with 5% reduced-graphene oxide (r-GO) by ultra-sonication process. The morphological, structural and thermal properties were investigated by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Raman Spectroscopy, Thermogravimetric Analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The effect of Co, Fe doping and r-GO on the conductivity of the synthesized samples was investigated by current-voltage (I-V) analysis. The perovskite structure was orthorhombic with particle size in 21.24 to 31.58 nm range. Crystal violet (CV) dye was selected for evaluation of photocatalytic activity (PCA) of the prepared materials under visible light irradiation. La 1-x Co x Cr 1-y Fe y O 3 /r-GO showed remarkably higher PCA as compared to pristine LaCrO 3 and La 1-x Co x Cr 1-y Fe y O 3. The r-GO composite furnished the CV dye degradation of 89.08% within 100 min irradiation under visible light at the light intensity in the range of 864.45-872.86 W/m 2. This valuable enhancement in PCA was due to the structural features of La 1-x Co x Cr 1-y Fe y O 3 /r-GO nanocomposite. In view of promising PCA, the composite has potential for the catalytic degradation of dyes in effluents using sunlight irradiation.