Synthesis and Characterization of CeO2/CuO Nanocomposites for Photocatalytic Degradation of Methylene Blue in Visible Light (original) (raw)
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University of Kashan, 2022
In this work, CuO/CeO 2 nancomposite was prepared via hydrothermal route. The product was prepared under 12 h and 150 o C. The shape, size, and crystalline structure have been investigated through using various techniques such as the scanning electron microscopy (SEM), with energy dispersive X-ray (EDX), the X-ray diffraction analysis (XRD), the Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The magnetic properties of prepared nanocomposites were studied via vibrating-sample magnetometer (VSM). Consequently, acid violet and rhodamine B dyes were applied for investigation the photocatalytic activity of prepared CuO/CeO 2 nanocomposite. Results showed that Acid violet and rhodamine B were photo-decolorization under UV irradiation after 120 minutes with 95.8 % and 88.2% respectively. This excellent performance was due to the suitable band structure of synthesized CuO/ CeO 2 nanocomposites which led to depress the recombination of photogenerated electrons and holes with increased the acidity of CeO 2 after incorporation it with CuO in the crystal lattice. This work introduces new nanocomposites for decolorization of organic pollutants from wastewater.
Visible light induced degradation of methylene blue using CeO 2 /V 2 O 5 and CeO 2 /CuO catalysts
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights In the present study, the nanocatalysts CeO 2 , V 2 O 5 , CuO, CeO 2 /V 2 O 5 and CeO 2 /CuO were synthesized by thermal decomposition method. This method is simple, fast and cost effective compared with other preparation methods. The synthesized catalysts were characterized by different techniques. The XRD and XPS results confirmed the structure and the oxidization states of the nanocomposite materials. DRS results suggested that the prepared CeO 2 /V 2 O 5 and CeO 2 /CuO nanocomposites can generate more electrons and holes under visible light irradiation. The photocatalytic activities of prepared catalysts were evaluated using the degradation of aqueous methylene blue solution as a model compound under visible light irradiation. In addition, the nanocomposite (CeO 2 /V 2 O 5 and CeO 2 /CuO) materials were employed to degrade the textile effluent under visible light condition.
Facile Synthesis and Characterization of CuO-CeO 2 Nanostructures for Photocatalytic Applications
Crystal Research Technology, 2022
A simple approach composite hydroxide mediated technique is applied successfully for the preparation of efficient CuO and CuO-CeO 2 photocatalysts. The structural, morphological, and optical characteristics of synthesized photocatalysts are probed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and UV-vis spectroscopy. The XRD and XPS reveal the successful formation of pure CuO and CuO-CeO 2 nanocomposite structures. Spherical, nanorods, nanosheets poly edge type peculiarities are found in SEM images. EDX backs the results of XRD and XPS. Bandgap energy of synthesized photocatalysts is found between 1.49 and 1.36 eV indicating red shift. Compared with pure CuO photocatalysts the CuO-CeO 2 composites effectively degrade the MB dye. The efficiency of CuO/CeO 2 (90:10) nanocomposite exhibit 99.01% efficiency and follow the pseudo first order kinetic reaction.
Synthetic CeO 2 Nanoparticle Catalysis of Methylene Blue Photodegradation: Kinetics and Mechanism
CeO 2 nanocrystals were synthesized by a simple precipitation method and calcination at 600 °C. (NH 4) 2 Ce(NO 3) 6 and ammonia were used as precursors. The CeO 2 nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and N 2 adsorption. The photodegradation of methylene blue catalyzed by CeO 2 nanoparticles was studied under UV and sunlight irradiation. The highest degradation was obtained with 1.0 g/L CeO 2 at pH 11 within 125 min. The pseudo first order rate constants of dye bleaching were calculated as 16.2 × 10 −3 and 15.7 × 10 −3 min −1 under UV and sunlight irradiation, respectively. The effect of iso-PrOH, iodide ion, and H 2 O 2 was studied to predict the pathway of dye degradation. The obtained results indicate the effect of photogen-erated holes in the degradation mechanism of the dye. Also, the photocatalytic activity of the prepared photocatalyst was studied in the presence of several negative ions.
Journal of Photochemistry and Photobiology A: Chemistry, 2018
Mixed oxide interfaces are critical in the delivery of active components in photocatalytic processes. Cerium doped TiO 2 photocatalysts were prepared using a hydrothermal route to manipulate the morphology of the photocatalyst and improve the interaction between CeO 2 and TiO 2 nanoparticles. These changes were compared with the photocatalytic activity and adsorption capacity of the solids. The photocatalysts were used to degrade polyvinylpyrrolidone (PVP) and methylene blue (MB) as test compounds. A low photodegradation rate of PVP (0.0001 min À1 and 0.0005 min À1 under visible and UV light, respectively) was observed using Ce-doped photocatalysts, with no adsorption. The high adsorption capacity of MB (34.46 mg g À1) proved that the local morphology of the nanostructured CeO 2 /TiO 2 photocatalysts is more important than the amount of CeO 2 in the sample, and the main role of the CeO 2 on mixed photocatalysts is to improve thermal stability during the synthesis. XRD, XPS, BET surface area, UV-vis and TEM techniques confirmed this conclusion. The rate of degradation of MB by the Ce-doped photocatalyst decreased dramatically when using the singlet oxygen scavenger L-Histidine (0.0214 min À1 to 0.0001 min À1), indicating a photocatalysis sensitized by the dye, under visible and UV light.
Journal of Water and Environmental Nanotechnology, 2021
Nanocrystalline UV light induced composite CeO2:SiO2 with high surface area and low band gap energy were prepared in order to assess its photocatalytic degradation capacity of target pollutant (mixture of dyes). The complete mineralization of target dye pollutants (30 ppm) occurred within 150 min. when CeO2:SiO2 catalyst with optimum loading 0.4 g was used. Overall, the present system is economical, reproducible and highly efficient. Further the comparative study on photocatalytic efficiency of SiO2 and CeO2 was compared with composite CeO2:SiO2. The effect of various operational parameters used in degradation like concentration of dye, amount of photocatalyst and various catalyst has been studied on the rate of reaction. The recyclability of the photocatalyst, CeO2:SiO2 was performed up to four runs. The photodegradation of waste water pollutants was occurred nearly 96 % using CeO2:SiO2 nanoparticles. The removal of waste water pollutants was confirmed by UV spectrophotometer by diminishing the absorbance to zero within 120 min using CeO2:SiO2 nanoparticles. The synthesized catalyst was characterized by various analytical investigative techniques like UV-DRS, FTIR, XRD, SEM, TEM and BET.
Journal of Water and Environmental Nanotechnology, 2021
In this study, p-n junction photocatalyst CuO/CeO2ZrO2 with different concentrations of CuO was prepared by auto solution combustion method using glycine as fuel. This method is simple, fast and cost effective compared with other preparation methods. The photocatalyst was characterized by X-ray diffraction (XRD), energy-dispersive spectrometer (EDS), UV-vis DRS. The assembly of p-type CuO nanoparticles produces a large number of nano p–n junction heterostructures on the surface of the CeO2ZrO2 nanocrystals, where CuO and CeO2ZrO2 form p- and n-type semiconductors. The experimental results reveal that p–n junction CuO/CeO2-ZrO2 heterojunction nanostructures exhibit much higher visible-light photocatalytic activities than the n-CeO2-ZrO2 for the removal of dye from industerial waste water. The photocatalytic activity of the p-n CuO/CeO2-ZrO2 heterojunction photocatalyst was evaluated using the degradation of aqueous methylene blue solution (MB) under visible light irradiation(λ>420 nm). The photo-degradation rate of this catalyzed is much faster than those occurring on n-type CeO2ZrO2. The sample with a p-n CuO/ CeO2-ZrO2 molar ratio of 0.021 presented the best photocatalytic activity, which was 30% higher than that of n-type CeO2ZrO2. The heat treatment condition also influences the photocatalytic activity strongly, and the best preparation condition is about 400ºC for 4h.
Synthesis of CeO2/TiO2 nanotubes and heterogeneous photocatalytic degradation of methylene blue
Journal of Environmental Chemical Engineering, 2018
In this study, the preparation of CeO2/ TiO2 nanotubes (CeO2/TiO2-NTs) is demonstrated using the hydrothermal method. The conditions for the synthesis were optimised using the Box-Behnken design. The samples obtained were characterised by means of X-ray diffraction, highresolution transmission electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, nitrogen adsorption/desorption isotherms, and Raman spectroscopy. The photocatalytic behaviour under visible light and kinetics of the CeO2/TiO2-NTs catalyst via methylene blue degradation were addressed. The results showed that the introduction of CeO2 into TiO2-NTs enhanced the photocatalytic activity in the visible light region. CeO2/TiO2-NTs were stable and potential as a visible light photocatalyst for the organic substances degradation in aqueous solutions.
Desalination and Water Treatment, 2021
In this study, CeO 2 /TiO 2 nanocomposites (NCs) were synthesized by adopting a straightforward two steps method comprising, first, the synthesis of CeO 2 and TiO 2 nanoparticles by wet chemical precipitation method and second, the heterostructure CeO 2 /TiO 2 NCs by solid-state reaction process. The CeO 2 /TiO 2 NCs were characterized by X-ray diffraction, N 2 adsorption-desorption isotherm analysis, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis diffuse reflectance spectroscopy. Regardless of CeO 2 content, the bandgap energies of CeO 2 / TiO 2 NCs were lower than that of pure TiO 2. Photocatalytic activity of the synthesized photocatalysts was assessed by degrading a model dye methylene blue under the illumination of UV light. The CeO 2 /TiO 2 NCs containing 2 wt% CeO 2 exhibited higher photocatalytic degradation efficiency compared to reference TiO 2 (P25), pure TiO 2 , and CeO 2 /TiO 2 NCs containing CeO 2 other than 2 wt%. The alkaline environment was favorable for photocatalytic decomposition of cationic dye methylene blue (MB). The enhanced degradation efficiency of CeO 2 /TiO 2 NCs was substantiated in terms of vectorial charge separation and the reduction of photogenerated charge carriers owing to the band offsets existing at the interface between CeO 2 and TiO 2 NPs. Finally, no significant change in the degradation efficiency of CeO 2 /TiO 2 NCs after successive uses evidenced the stability and reusability of the photocatalysts. Therefore, it can be concluded that the synthesized CeO 2 /TiO 2 heterostructure photocatalyst would be a promising candidate for application in wastewater treatment.
Nanomaterials, 2020
The construction of heterostructured photocatalyst with an appropriate energy band structure will help realize highly efficient photo-excited charge separation. In this study, ternary CuO/CeO2/ZnO nano-particle (NP) composites were synthesized by a facile two-step sol-gel method, which exhibit significantly enhanced photocatalytic degradation performance for various organic pollutants under UV and visible light excitation. The photo-responses to both UV and visible light, as well as the visible light absorption and utilization rates of ZnO are found to be synergistically intensified by CeO2 and CuO co-coupling. The first-order kinetic constants (K) of 3%CuO/CeO2/ZnO for methylene blue (MB) degradation are ~3.9, ~4.1 and ~4.8 times higher than ZnO under UV light, visible light and simulated sunlight illumination, respectively. The roles of CuO and CeO2 in optical properties and photo-degradation under UV and visible light were explored. Besides, the photogenic holes (h+) of ZnO, CeO2...