scholarly journals Preparation of highly active zinc oxide for photocatalytic removal of phenol: Direct calcination versus co-precipitation method

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Faisal Hussin ◽  
Hendrik O. Lintang ◽  
Lee Siew Ling ◽  
Leny Yuliati
Keyword(s):  
Zinc Oxide ◽  
Uv Light ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Highly Active ◽  
Uv Light Irradiation ◽  
Photocatalytic Removal ◽  
Volmer Plot ◽  
Xrd Patterns ◽  
Co Precipitation

Photocatalytic removal of phenol under UV light irradiation was studied on zinc oxide (ZnO) photocatalysts, which were prepared via direct calcination (DC), and co-precipitation (CP) methods. The XRD patterns revealed that all of the prepared ZnO samples showed wurtzite structure, in which the ZnO-CP showed higher intensity of the diffraction peaks than the ZnO-DC sample. Optical and fluorescence properties of the prepared ZnO samples were similar to each other as confirmed by DR UV-Vis and fluorescence spectroscopy, respectively. The Stern-Volmer plot was investigated to study the interactions between the emission sites and the phenol. It was obtained that the emission sites of the ZnO-CP gave better interactions towards phenol molecules as compared to the ZnO-DC. After 6 hours reaction under UV light irradiation, the ZnO-CP sample showed two times higher photocatalytic activity for removal of phenol (10%) than that of the ZnO-DC (5%). It was suggested that the high activity observed on the ZnO-CP sample would be due to high crystallinity and good interactions with phenol. These results clearly suggested that the co-precipitation method was a good approach to prepare the highly active ZnO for the photocatalytic removal of phenol.

PHOTOCATALYTIC REMOVAL OF PHENOL OVER MESOPOROUS ZnO/TiO2 COMPOSITES

2018 ◽  
Vol 80 (2) ◽  
Author(s):  
Klinsmann Cheong Lee Khang ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Leny Yuliati
Keyword(s):  
Pore Size ◽  
Uv Light ◽  
Average Pore Size ◽  
Anatase Tio2 ◽  
Light Irradiation ◽  
Molar Ratio ◽  
Average Pore ◽  
Uv Light Irradiation ◽  
Photocatalytic Removal ◽  
Mesoporous Zno

A series of mesoporous ZnO/TiO2 composites were successfully synthesized using cetyltrimethylammonium bromide surfactant. The composites of different Zn:Ti molar ratios (0.5:1, 0.75:1, and 1:1) were prepared by impregnating ZnO onto mesoporous TiO2. XRD results verified co-existence of both anatase TiO2 and hexagonal wurtzite ZnO in the ZnO/TiO2 composites. Based on the Tauc plots, all the composites showed almost the same band gap energy of approximately 3.21 eV. The fourier transform infrared spectroscopy results successful covering of ZnO on the surface of the TiO2 as the hydrophilicity property of TiO2 decreased remarkably with the loading of ZnO in the composites. N2 adsorption-desorption isotherms of the samples exhibited type-IV isotherm with a hysteresis loop. The Barrett-Joyner-Halenda pore size distribution revealed that the average pore size of the composites was around 3.6 nm, indicating the formation of mesopores dominantly in the samples. The photocatalytic removal of phenol over the samples under UV light irradiation after 3 h decreased in the order: ZnO/TiO2 composites > anatase TiO2 (with surfactant) > anatase TiO2 (without surfactant) > ZnO. The composite with Zn:Ti molar ratio of 0.75:1 has achieved the highest photocatalytic activity of 36.5% in the removal of phenol under UV light irradiation for 3 h.

scholarly journals Anatase TiO2 nanoparticle coating on porous COK-12 platelets as highly active and reusable photocatalysts

RSC Advances ◽  
2016 ◽  
Vol 6 (52) ◽  
pp. 46678-46685 ◽  
Author(s):  
L. H. Wee ◽  
M. Meledina ◽  
S. Turner ◽  
K. Custers ◽  
S. Kerkhofs ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Organic Pollutants ◽  
Uv Light ◽  
Anatase Tio2 ◽  
Light Irradiation ◽  
Ordered Mesoporous Silica ◽  
Nanoparticle Coating ◽  
Highly Active ◽  
Uv Light Irradiation ◽  
Ordered Mesoporous

Coating of anatase TiO2 nanoparticles on ordered mesoporous silica COK-12 platelets for effective photodegradation of various organic pollutants under UV light irradiation.

scholarly journals Study on quenching effect of nitrite ions on zinc oxide modified by polyvinylpyrrolidone

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Ing Hua Tang ◽  
Siti Zarina Mohd So’ad ◽  
Hendrik O. Lintang ◽  
Leny Yuliati
Keyword(s):  
Zinc Oxide ◽  
Chemical Properties ◽  
Precipitation Method ◽  
Broad Absorption Band ◽  
Quenching Effect ◽  
Physical Mixing ◽  
Mixing Method ◽  
Volmer Plot ◽  
Co Precipitation ◽  
Physical And Chemical

Zinc oxide (ZnO) is appeared to be an attractive material for application for multidisciplinary fields, owing to its unique physical and chemical properties. In this study, ZnO was synthesized using the co-precipitation method, where the zinc acetate was used as the precursor. The ZnO was further modified by adding different amounts of polyvinylpyrrolidone (PVP) via simple physical mixing method to obtain PVP/ZnO composites. The ZnO and the PVP/ZnO composites were characterized using Fourier transform infrared (FTIR), diffuse reflectance ultraviolet-visible (DR UV-Vis), and fluorescence spectroscopy. The FTIR spectra detected the presence of ZnO group and the functional groups from the PVP. The PVP peaks become more apparent with the increase of the PVP amount. From the DR UV-Vis spectra, no significant change was observed after modification with the PVP, and all composites showed similar broad absorption band to that of the ZnO. The fluorescence spectra showed that the addition of PVP decreased the emission intensity and red shifted the peak wavelength, indicating certain interactions between the ZnO and the added PVP. Quenching study was investigated in the presence of nitrite ions (NO2-) with various concentrations (2-10 mM). A linear Stern-Volmer plot was observed and the highest quenching constant rate (KSV) was obtained on the PVP/ZnO sample with PVP content of 0.1 wt%. This study demonstrated that the addition of the PVP on the ZnO improved the interaction between the ZnO and the NO2-, which will be one of the important factors for sensing and catalytic applications for detection and conversion of NO2-.

Construction of ZnxCd1−xS/CeO2 composites for enhanced photocatalytic activity and stability by chemical precipitation method

2021 ◽  
pp. 2150334
Author(s):  
Yi-Feng Chai ◽  
Zhong-Hua Zhu ◽  
Ming-Wei Liu ◽  
Jing Zeng ◽  
Gui-Fang Huang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Uv Light ◽  
Chemical Precipitation ◽  
Charge Carriers ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Uv Light Irradiation

Development photoinduced photocatalysts is a significant approach to improve photocatalytic activity and stability. Herein, we successfully prepared Zn[Formula: see text]Cd[Formula: see text]S/CeO2 composites by a facile method. It is found that the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 composites show significant enhancement in photocatalytic activity for methyl orange (MO) degradation under visible and UV light irradiation. The degradation efficiency reaches up to 3.7 times higher than that of pure CeO2 under visible light irradiation. Moreover, the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 samples have almost no loss of photocatalytic activity after five recycles, indicating good photocatalytic stability of the samples. The attractive photocatalytic activity of the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 samples could be attributed to the robust charge carriers transfer and separation.

Montmorillonite Incorporated in Cr Doped ZnO Nanoparticles for Degradation of Organic Dyes in Water under UV Light Irradiation

2015 ◽  
Vol 1123 ◽  
pp. 316-321 ◽  
Author(s):  
Vici Tritella Carmida ◽  
Mia Putri Rahmawati ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh
Keyword(s):  
Methylene Blue ◽  
Zno Nanoparticles ◽  
Congo Red ◽  
Organic Dyes ◽  
Uv Light ◽  
Organic Pollutant ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Uv Light Irradiation ◽  
Doped Zno

In this study, the photocatalytic degradation of methylene blue and congo red has been investigated using montmorillonite modified Cr-doped ZnO nanoparticles. Chromium doped zinc oxide nanoparticles were synthesized by co-precipitation method and were characterized using X-ray diffraction, Fourier-transform infrared absorption and UV-visible spectrophotometer. Furthermore these nanoparticles were explored to degradation of methylene blue and congo red in aqueous solution as model of organic pollutant under UV light irradiation. Comparison of degradation efficiency demonstrated that Cr-doped ZnO nanoparticles modified montmorillonite exhibited higher activity than pure Cr-doped ZnO.

Photocatalytic reduction of Cr(VI) from agricultural soil column leachates using zinc oxide under UV light irradiation

2012 ◽  
Vol 33 (23) ◽  
pp. 2673-2680 ◽  
Author(s):  
R. Delgado-Balderas ◽  
L. Hinojosa-Reyes ◽  
J. L. Guzmán-Mar ◽  
M. T. Garza-González ◽  
U. J. López-Chuken ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Agricultural Soil ◽  
Uv Light ◽  
Soil Column ◽  
Photocatalytic Reduction ◽  
Light Irradiation ◽  
Uv Light Irradiation

Synthesis and Photocatalytic Activity of Rod-Shaped Mesoporous TiO2 Using Poly (ethylene glycol) as Templates

2013 ◽  
Vol 634-638 ◽  
pp. 2272-2275
Author(s):  
Chang Wang Shao ◽  
Guo Wei Zhou ◽  
De Lan Xu ◽  
Bin Sun
Keyword(s):  
Photocatalytic Activity ◽  
Ethylene Glycol ◽  
Uv Light ◽  
Light Irradiation ◽  
Homogeneous Precipitation ◽  
Poly Ethylene Glycol ◽  
Structure Directing Agent ◽  
Uv Light Irradiation ◽  
Poly Ethylene ◽  
Xrd Patterns

Rod-shaped TiO2 was synthesized via homogeneous precipitation by using PEG and urea as the structure directing agent and precipitation agent, respectively. The prepared samples were characterized by XRD, TEM, and FESEM. The XRD patterns of the samples indicated that the crystalline phase was anatase. TEM and FESEM images revealed the morphology of prepared TiO2 samples were rod-shaped, and densely packed with plenty of spherical-shaped units. RTS3 exhibited the highest photocatalytic activity for degradation of papermaking wastewater under UV light irradiation. CODCr percent degradation was about 75% under UV light irradiation in 12 h for RTS3.

Recyclable Natural Magnetite Nanoparticles for Effective Degradation of Methylene Blue in Water under UV Light Irradiation

2020 ◽  
Vol 855 ◽  
pp. 315-321
Author(s):  
Nandang Mufti ◽  
Siti Maryam ◽  
Henry Setiyanto ◽  
Ahmad Taufiq ◽  
Sunaryono
Keyword(s):  
Methylene Blue ◽  
Magnetite Nanoparticles ◽  
Uv Light ◽  
Light Irradiation ◽  
Additional Advantage ◽  
Uv Light Irradiation ◽  
Fenton Catalyst ◽  
Ability To Act ◽  
Materials Used ◽  
Co Precipitation

Among the numerous materials used for dye removal, magnetite is particularly interesting due to its ability to act as an adsorbent and a Fenton catalyst, being easily separable by application of a magnetic field and reusable. Herein, we describe a co-precipitation–based synthesis of magnetite nanoparticles (particle size = 11 nm, surface area = 147.12 m2 g–1) from iron sand and investigate their effectiveness for methylene blue (MB) degradation. The above nanoparticles could promote the decomposition of MB both in the dark (via adsorption) and under UV light irradiation (via Fenton-type degradation), exhibiting the additional advantage of recyclability. Thus, MB degradation efficiencies are 76.32, 76.08, and 68.52% for first, second, and third cycles, respectively, indicating that the prepared magnetic material is a promising recyclable catalyst for the decontamination of dye-containing wastewater. The photo Fenton reactions take to account for reproducibility of MB degradation.

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