Enhanced photocatalytic activity of nanocomposites of TiO2 doped with Zr, Y or Ce polyoxometalates for degradation of methyl orange dye

2016 ◽  
Vol 73 (7) ◽  
pp. 1746-1755 ◽  
Author(s):  
Roushan Khoshnavazi ◽  
Shler Fereydouni ◽  
Leila Bahrami
Keyword(s):  
Electron Microscopy ◽  
Methyl Orange ◽  
Diffuse Reflectance Spectroscopy ◽  
Textile Dye ◽  
Impregnation Method ◽  
Doped Tio2 ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Metal Doped ◽  
Degradation Of Methyl Orange

The synergistic effect of polyoxometalate (POM) and metal-doped TiO2 (metal = Zr, Y and Ce) was examined, to fabricate nanocomposites with enhanced photocatalytic activities toward the degradation of methyl orange (MO), as a model textile dye. A series of new nanocomposites, containing different loading amounts of H9Na3[WZn3(H2O)2(ZnW9O34)2].24H2O (HZnW) (10–30%) on each of the metal-doped TiO2 nanoparticles, were synthesized using impregnation method. The morphology and crystal phase of the as-prepared nanocomposites were investigated by various characterization techniques: Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray analysis and diffuse reflectance spectroscopy, indicating that the HZnW and metal-doped TiO2 had been successfully incorporated into the nanocomposite structure. The effects of parameters such as loading amount of HZnW, catalyst dose, pH and initial concentration of dye solution were investigated on the degradation kinetics and it was interestingly found that the prepared nanocomposites could efficiently degrade the MO dye in 5–7 min under UV light irradiation. The best results were obtained for the HZnW-Zr-TiO2 among the different nanocomposites. Also, control studies showed the superior photocatalytic properties of composites compared to that of the individual components. The facile preparation and their improved photocatalytic activities suggest that these materials can have a promising future for water and wastewater purifications.

Preparation and Properties of Eu3+-Doped TiO2 Nanowires

2012 ◽  
Vol 624 ◽  
pp. 67-71
Author(s):  
Si Qin Zhao ◽  
Hong Liang Wan ◽  
S. Asuha
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sodium Titanate ◽  
X Ray ◽  
Valence States ◽  
Photocatalytic Activities ◽  
Crystallite Sizes ◽  
Degradation Of Methyl Orange

Nanowires of sodium titanate, TiO2 and Eu3+/TiO2 were synthesized by hydrothermal method, and their microstructure, optical properties and valence states of exterior elements were characterized by X-ray powder diffraction (XRD), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectroscopy techniques. At the same time, the photocatalytic activities of the materials for degradation of methyl orange under visible-light irradiation were also investigated. The results showed the formation of nanowires of sodium titanate with average crystallite sizes of 50-200 nm and in lengths from several microns to several dozens microns, and its chemical formula was determined to be Na2Ti3O7. TiO2 and Eu3+ /TiO2nanowires were prepared from the Na2Ti3O7 nanowires via ion exchange (i.e., with H+ and Eu3+ ions) and high temperature sintering processes. These three kinds of nanowires showed different photocatalytic activities for degradation of methyl orange. Na2Ti3O7 nanowire did not show any photocatalytic activity for methyl orange degradation, while TiO2 nanowire was superior to Na2Ti3O7 nanowire; and, Eu3+/ TiO2 nanowire possessed the highest photocatalytic activity.

Preparation of Bismuth-Lanthanum Composite Oxide and its Photocatalytic Performance

2012 ◽  
Vol 616-618 ◽  
pp. 1667-1670
Author(s):  
Ting Tang ◽  
Hong Quan Deng ◽  
Qi Ying Jiang ◽  
Ji Chuan Huo ◽  
Shun Hua Hu
Keyword(s):  
Methyl Orange ◽  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Optimum Amount ◽  
Composite Oxide ◽  
X Ray ◽  
Molecular Precursor ◽  
Degradation Of Methyl Orange

Bi-La composite oxide was prepared by thermal decomposition of molecular precursor of BiLa(dtpa)(NO3)•3.5H2O (dtpa=Diethylene triaminepentaacetic). The effect of calcinated temperature on structure was discussed by X-ray powder diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectroscopy. The photocatalytic performance of samples prepared was discussed through the degradation of methyl orange. The results show that Bi-La composite oxide prepared at 500°C exhibits the best photocatalytic activity for the degradation of methyl orange (20mg/L) and the optimum amount of photocatalyst is 1.0 g/L.

scholarly journals Synthesis and Characterization of Sr-Doped ZnSe Nanoparticles for Catalytic and Biological Activities

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2189
Author(s):  
V. Beena ◽  
S. L. Rayar ◽  
S. Ajitha ◽  
Awais Ahmad ◽  
Munirah D. Albaqami ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Biological Activities ◽  
Water Remediation ◽  
Precipitation Method ◽  
Znse Nanoparticles ◽  
X Ray ◽  
Degradation Of Methyl Orange

The development of cost-effective and ecofriendly approaches toward water purification and antibacterial activity is a hot research topic in this era. Purposely, strontium-doped zinc selenide (Sr-doped ZnSe) nanoparticles, with different molar ratios of Sr2+ cations (0.01, 0.05, and 0.1), were prepared via the co-precipitation method, in which sodium borohydride (NaBH4) and 2-mercaptoethanol were employed as reducing and stabilizing agents, respectively. The ZnSe cubic structure expanded by Sr2+ cations was indicated by X-ray diffraction (XRD) analysis. The absorption of the chemical compounds on the surface was observed via Fourier transform infrared (FT-IR) spectroscopy. The optical orientation was measured by ultraviolet–visible diffused reflectance spectroscopy (UV-DRS) analysis. The surface area, morphology, and elemental purity were analyzed using field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive spectroscopy (EDS) analyses. The oxidation state and valency of the synthesized nanoparticles were analyzed using X-ray photoelectron spectroscopy (XPS). Sr-doped ZnSe nanoparticles were investigated for photocatalytic degradation of methyl orange (MO), and their antibacterial potential was investigated against different bacterial strains. The antibacterial activity examined against Staphylococcus aureus and Escherichia coli implied the excellent biological activity of the nanoparticles. Moreover, the Sr-doped ZnSe nanoparticles were evaluated by the successful degradation of methyl orange under visible light irradiation. Therefore, Sr-doped ZnSe nanoparticles have tremendous potential in biological and water remediation fields.

Preparation of Nanostructured Ag/CeO2 by Microwave Synthesis and its Photocatalysis Activity

2012 ◽  
Vol 624 ◽  
pp. 88-93 ◽  
Author(s):  
En Lei Qi ◽  
Ben Niu ◽  
Shi Lei Zhang ◽  
Jie Qiang Wang
Keyword(s):  
Methyl Orange ◽  
Degradation Rate ◽  
Raw Materials ◽  
Dye Decolorization ◽  
Precipitation Method ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Homogeneous Precipitation Method ◽  
Degradation Of Methyl Orange

CeO2 nanobundles were obtained by the microwave homogeneous precipitation method using cerium nitrate and urea as raw materials. Ag nanoparticles were obtained by the microwave solvolthermal method using silver nitrate, PVP and ethanol as raw materials. Nanostructured Ag/CeO2 was prepared by the impregnation method. The products were characterized by X-ray diffraction, SEM, TEM, UV-vis spectrum, BET. The photocatalytic properties of CeO2 and Ag/CeO2 nanomaterials were evaluated by degradation of methyl orange. The results show that the photocatalytic degradation of modified cerium oxide modified by nano silver on methyl orange is significantly improved. For the Ag (0.1 wt%)/CeO2 material, the degradation rate on methyl orange is up to 83.2% under visible light irradiation for 1h. The catalytic activity of nanostructured Ag (0.1 wt%)/CeO2 in dye decolorization is substantially higher than the standard reference TiO2 P25.

Photocatalytic Degradation of Methyl Orange and Phenol by BiVO4-Loaded Fly Ash Cenospheres (FACs) Composite

2013 ◽  
Vol 821-822 ◽  
pp. 471-475 ◽  
Author(s):  
Yu Xin Sun ◽  
Jin Zhang
Keyword(s):  
Fly Ash ◽  
Methyl Orange ◽  
Photocatalytic Performance ◽  
Phenol Degradation ◽  
X Ray ◽  
Practical Applications ◽  
Photocatalytic Activities ◽  
Metalorganic Decomposition ◽  
Degradation Of Methyl Orange ◽  
Fly Ash Cenospheres

A novel photocatalyst, BiVO4-loaded fly ash cenospheres (BFACs), was prepared by the modified metalorganic decomposition (MOD) method. Its physicochemical properties were characterized by X-ray diffractometry (XRD), Raman spectroscopy, scanning electron microscopy with energy dispersive X-ray microanalyses (SEM-EDX) and UV-vis diffused reflectance spectroscopy (DRS). The photocatalytic activities of the as-prepared sample were evaluated by the photodegradation methyl orange (MO) dye and phenol in aqueous solution under visible-light irradiation. It was found that the photocatalytic activity of BFACs composite for the degradation of MO and phenol were higher than that of pure BiVO4. Moreover, much enhanced photocatalytic performance for phenol degradation was also realized with the assistance of H2O2. The BFACs photocatalysts were stable and maintained high photocatalytic efficiency of MO during repeated recycles. The BFACs photocatalyst is promising for practical applications in purification of dye-containing wastewater.

Photocatalytic removal of 2-nitrophenol using silver and sulfur co-doped TiO2 under natural solar light

2015 ◽  
Vol 72 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Mehrzad Feilizadeh ◽  
Amin Delparish ◽  
S. Toufigh Bararpour ◽  
Hamed Abedini Najafabadi ◽  
S. Mohammad Esmaeil Zakeri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Diffuse Reflectance Spectroscopy ◽  
Solar Light ◽  
Morphological Properties ◽  
Doped Tio2 ◽  
X Ray ◽  
Bare Tio2 ◽  
Co Doping ◽  
Co Doped

To overcome the drawback of poor solar light utilization brought about by the narrow photoresponse range of TiO2, a silver and sulfur co-doped TiO2 was synthesized. Using the prepared catalyst, solar photocatalytic degradation of 2-nitrophenol (2-NP) by a TiO2-based catalyst was studied for the first time. Effects of the co-doping on the structural, optical and morphological properties of the synthesized nanoparticles were investigated by different characterization methods: X-ray diffraction, N2 adsorption–desorption measurements, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, UV–visible diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. Solar experiments showed that the co-doping with silver and sulfur significantly increased the photocatalytic activity. In various initial concentrations of 2-NP more than 99% of the contaminant was decomposed by Ag-S/TiO2 in less than 150 minutes, while the degradation efficiency was much less in the presence of bare TiO2. Kinetic studies suggested that solar photocatalytic degradation of 2-NP is consistent with the Langmuir–Hinshelwood model. The rate constant of the reaction and adsorption constant of the modified photocatalyst were found to be 2.4 and 4.1 times larger than that of bare TiO2, respectively.

scholarly journals Photocatalytic Antibacterial Effectiveness of Cu-Doped TiO2 Thin Film Prepared via the Peroxo Sol-Gel Method

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 352 ◽  
Author(s):  
Benjawan Moongraksathum ◽  
Jun-Ya Shang ◽  
Yu-Wen Chen
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Light Irradiation ◽  
Gel Method ◽  
Doped Tio2 ◽  
X Ray ◽  
Photocatalytic Activities

Cu-doped titanium dioxide thin films (Cu/TiO2) were prepared on glass substrate via peroxo sol-gel method and dip-coating process with no subsequent calcination process for the degradation of organic dye and use as an antibacterial agent. The as-prepared materials were characterised using transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). For photocatalytic degradation of methylene blue in water, the samples were subjected to Ultraviolet C (UVC) and visible light irradiation. Degraded methylene blue concentration was measured using UV-Vis spectrophotometer. The antibacterial activities of the samples were tested against the gram-negative bacteria Escherichia coli (ATCC25922). Copper species were present in the form of CuO on the surface of modified TiO2 particles, which was confirmed using TEM and XPS. The optimal observed Cu/TiO2 weight ratio of 0.5 represents the highest photocatalytic activities under both UVC and visible light irradiation. Moreover, the same composition remarkably exhibited high antibacterial effectiveness against E. coli after illumination with ultraviolet A. The presence of CuO on TiO2 significantly enhanced photocatalytic activities. Therefore, active Cu-doped TiO2 can be used as a multipurpose coating material.

Hydrothermal Synthesis, Characterization and Photocatalytic Properties of Zn/Sn-Composite Oxides

2010 ◽  
Vol 148-149 ◽  
pp. 1204-1207
Author(s):  
Jing Hu ◽  
Ming Guo Ma ◽  
Jian Zhang Li
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Composite Oxides ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Degradation Of Methyl Orange

The Zn/Sn-composite oxide nanogranules were synthesized via a simple hydrothermal method, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show that the hydrothermal temperature significantly influences the morphology, microstructure, and composition of the as-prepared samples. And the nano-sized ZnO/Zn2SnO4 exhibited high photocatalytic activities on the degradation of methyl orange (MO) under ultraviolet (UV) light irradiation.

scholarly journals Solvothermal Synthesis of ZnO Nanoparticles for Photocatalytic Degradation of Methyl Orange and p-Nitrophenol

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3224
Author(s):  
Ying Wang ◽  
Chuanxi Yang ◽  
Yonglin Liu ◽  
Yuqi Fan ◽  
Feng Dang ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Zno Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Zno Nps ◽  
Uniform Size ◽  
X Ray ◽  
Degradation Rates ◽  
Degradation Of Methyl Orange

The photocatalytic degradation of organic pollutants is an effective method of controlling environmental pollution. ZnO nanoparticles (ZnO NPs) were prepared by the solvothermal method and characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–visible diffuse reflectance spectroscopy (UV–Vis DRS). The results showed that the ZnO NPs had a uniform size of 25–40 nm, hexagonal wurtzite structure, and a band gap of 2.99 eV. The photocatalytic degradation of methyl orange (MO) and p-nitrophenol (PNP) was used as a model reaction to evaluate the photocatalytic activity of ZnO NPs. The photocatalytic degradation rates (pseudo-first-order kinetics) of MO and PNP were 92% (0.0128 min−1) and 56.2% (0.0042 min−1), respectively, with a 25 W ultraviolet lamp, MO/PNP concentration = 20 mg/L, ZnO NPs dose = 1.5 g/L, and time = 180 min. The photocatalytic mechanism of ZnO NPs and degradation pathways of MO and PNP were also proposed. The results provide valuable information and guidance for the treatment of wastewater via photocatalytic methods.

Photocatalytic Properties of TiO2-Coatings Mounted on CaAl2O4:Eu2+, Nd3+ without Light Source

2009 ◽  
Vol 620-622 ◽  
pp. 671-674
Author(s):  
Hui Hui Li ◽  
Yu Hua Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Methyl Orange ◽  
Light Source ◽  
Sol Gel ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Degradation Of Methyl Orange

This paper aims at the investigation of photocatalytic properties of titanium dioxide coatings covering on the surfaces of long blue-emitting afterglow CaAl2O4:Eu2+, Nd3+ elaborated by a sol-gel method. Morphologies and microstructures of the coatings were observed mainly by transmission electron microscopy (TEM) and analyzed by X-ray diffraction (XRD). The photocatalytic behavior of the TiO2-base surfaces was evaluated by the degradation of methyl orange (MO) solution. It suggested that a layer of TiO2 film mounted on the phosphor particles successfully. Also, the TiO2 coatings had remained its photocatalytic role on the as-prepared sample even after the light source was removed. The inner long blue-emitting afterglow had released blue afterglow after removing light source and allowed for reactive TiO2 surfaces to be held for the removal of methyl orange.

Sign in / Sign up

Export Citation Format

Share Document