Photocatalytic Degradation of Rhodamine B Using MnO2 and ZnO Nanoparticles

2013 ◽  
Vol 756 ◽  
pp. 167-174 ◽  
Author(s):  
Yim Leng Chan ◽  
Swee Yong Pung ◽  
Nur Syafiqah Hussain ◽  
Srimala Sreekantan ◽  
Fei Yee Yeoh
Keyword(s):  
Rate Constant ◽  
Zno Nanoparticles ◽  
Uv Light ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Oxide Semiconductor ◽  
Manganese Sulfate ◽  
Gap Energy ◽  
Oxidizing Power ◽  
Sulfate Hydrate

The oxide semiconductor with different band gap energy i.e. manganese dioxide (MnO2) (Eg: 1.30eV) and zinc oxide (ZnO) (Eg: 3.37 eV) nanoparticles were used to degrade RhodamineB (RhB) under irradiation of UV light (254 nm).The MnO2nanoparticles were synthesized by hydrothermal method (160 °C, 4 h) using analytical grade manganese sulfate hydrate and potassium permanganate (VII) as precursors. The XRD analysis reveals that the nanoparticles were d-MnO2.The photocatalytic study shows that degradation of RhB solution by ZnO nanoparticles (rate constant: 0.02749 min-1) was approximately four times faster than the d-MnO2nanoparticles (rate constant:0.0067 min-1). This observation could be attributed to the higher reducing and oxidizing power of ZnO in producing free radicals for photodegradation of RhB solution.

scholarly journals Synthesis and Optical Properties of B-Mg co-Doped ZnO Nanoparticles

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 882
Author(s):  
Yuechan Li ◽  
Yongli Li ◽  
An Xie
Keyword(s):  
Optical Properties ◽  
Zno Nanoparticles ◽  
Great Influence ◽  
Structure Study ◽  
Band Gap Energy ◽  
One Pot ◽  
Gap Energy ◽  
Doping Impurity ◽  
Shrinkage Effect ◽  
Co Doped

Doping impurity into ZnO is an effective and powerful technique to tailor structures and enhance its optical properties. In this work, Zn1−xMgxO and Zn1−x−yMgxByO nanoparticles (x = 0, 0.1, 0.2, 0.3, 0.4; y = 0, 0.02, 0.04) were synthesized via one-pot method. It shows that the Mg and B dopants has great influence on crystallinity and surface morphology of ZnO nanoparticles, without changing the wurtzite structure of ZnO. The band structure study indicates that the competition of Conductive Band (CB) shift, Burstein–Moss (B-M) shift and Shrinkage effect will cause the band gap energy change in ZnO.

scholarly journals UV-light photocatalytic degradation of non-ionic surfactants using ZnO nanoparticles

2021 ◽  
Author(s):  
K. Huszla ◽  
M. Wysokowski ◽  
A. Zgoła-Grześkowiak ◽  
M. Staszak ◽  
M. Janczarek ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Uv Light ◽  
Degradation Mechanism ◽  
Spherical Shape ◽  
Xrd Analysis ◽  
Ionic Surfactants ◽  
Langmuir Hinshelwood Mechanism ◽  
Poly Ethylene ◽  
Terminal Oxidation ◽  
Triton X

AbstractThe aim of this study was to evaluate the performance of zinc oxide nanoparticles as a photocatalyst for photodegradation of two model non-ionic surfactants (Triton X-100 and C12E10). The first part of the investigation was focused on the synthesis and characterization of ZnO nanoparticles, since its crystalline structure strongly impacts its photocatalytic properties. Based on the results of the XRD analysis, it was concluded that the obtained material occurred in the form of hexagonal wurtzite with a polycrystalline structure. FT-IR and XPS analyses were used to elucidate and confirm the nanomaterial structure, whereas investigation of N2 adsorption/desorption and SEM/TEM imaging allowed to establish that the synthesized ZnO was characterized as a mesoporous material with uniform, spherical shape and particle size fluctuating between 90 and 130 nm. The second part of the study included spectrophotometric assessment of the photodegradation process. The use of the obtained ZnO nanoparticles allowed to achieve efficient photodegradation of both C12E10 (92%) and Triton X-100 (82%) after 1 h of UV irradiation. The Langmuir–Hinshelwood mechanism was used to describe the reaction kinetics. Subsequent LC-MS/MS analysis of the residues indicated that the degradation mechanism is most likely based on both central fission of the surfactant molecules with further terminal oxidation of poly(ethylene glycol) and terminal oxidation leading to carboxylic derivatives of surfactants.

scholarly journals Electrical, dielectric and photocatalytic properties of Fe-doped ZnO nanomaterials synthesized by sol gel method

2016 ◽  
Vol 10 (3) ◽  
pp. 125-135 ◽  
Author(s):  
Yacine Cherifi ◽  
Ahcène Chaouchi ◽  
Yannick Lorgoilloux ◽  
Mohammed Rguiti ◽  
Abdelaziz Kadri ◽  
...  
Keyword(s):  
Single Phase ◽  
Uv Light ◽  
Sol Gel ◽  
Complex Impedance ◽  
Hexagonal Wurtzite Structure ◽  
Band Gap Energy ◽  
Cbh Model ◽  
Gap Energy ◽  
Gel Technique ◽  
Doped Zno

Fe-doped ZnO nanoparticles were synthesized by sol gel technique. Fine-scale and single phase hexagonal wurtzite structure in all samples were confirmed by SEM and XRD, respectively. The band gap energy depends on the amount of Fe and was found to be in the range of 3.11-2.53 eV. The electric and dielectric properties were investigated using complex impedance spectroscopy. AC conductivity data were correlated with the barrier hopping (CBH) model to evaluate the binding energy (Wm), the minimum hopping distance (Rmin) and the density of states at Fermi level, N(EF). Fe doping in ZnO also improved the photocatalytic activity. Thus, the sample Zn0.95Fe0.05O showed high degradation potential towards methylene blue (MB), i.e. it degrades 90% of BM in 90min under UV light.

scholarly journals Detailed Spectroscopic and Structural Analysis of TiO2/WO3 Composite Semiconductors

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Biborka Boga ◽  
István Székely ◽  
Zsolt Pap ◽  
Lucian Baia ◽  
Monica Baia
Keyword(s):  
Charge Separation ◽  
Separation Efficiency ◽  
Uv Light ◽  
Band Gap Energy ◽  
Crucial Importance ◽  
Gap Energy ◽  
Spectroscopic Characteristics ◽  
Charge Separation Efficiency ◽  
Derived Data

WO3-TiO2 composite materials were obtained using commercial titania (Evonik Aeroxide P25) and hydrothermally crystallized WO3. Different ratios of TiO2/WO3 were investigated, starting at 1 wt.% of WO3 to 50 wt.%. The morphology of WO3 was of the star-like type, and its structure is basically composed of monoclinic crystalline phase. All spectroscopic characteristics of the composites and their derived data (band-gap energy value, light absorption threshold, and IR specific bands) directly varied with the increase of the WO3 content. However, the oxalic acid photodegradation achieved under UV light reached the highest yield for 24 wt.% WO3 content, a result that was attributed to the charge separation efficiency and the surface hydrophilicity. The latter mentioned reason points out the crucial importance of the surface quality of the investigated structure in photocatalytic tests.

scholarly journals Aluminum doping tunes band gap energy level as well as oxidative stress-mediated cytotoxicity of ZnO nanoparticles in MCF-7 cells

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohd Javed Akhtar ◽  
Hisham A. Alhadlaq ◽  
Aws Alshamsan ◽  
M.A. Majeed Khan ◽  
Maqusood Ahamed
Keyword(s):  
Oxidative Stress ◽  
Energy Level ◽  
Band Gap ◽  
Zno Nanoparticles ◽  
Band Gap Energy ◽  
Aluminum Doping ◽  
Gap Energy ◽  
Mcf 7

Photocatalytic Properties and Graphene Oxide Additional Effects in TiO2

2018 ◽  
Vol 280 ◽  
pp. 65-70
Author(s):  
N.A. Mohd Noor ◽  
S.K. Kamarudin ◽  
M. Darus ◽  
N.F. Diyana M. Yunos ◽  
M.A. Idris
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Band Gap ◽  
Uv Light ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Photodegradation Efficiency ◽  
Energy Conversation ◽  
Uv Light Irradiation ◽  
Promising Application

Photocatalytic activity in TiO2 attract great attention because it promising application in contaminations on degradation and energy conversation. However there is a need on TiO2 band gap modification to be equivalent with the visible light. Thus, inviting several method of addition certain elements including in this study, the additional of graphene oxide (GO) was investigated. GO were prepared by Hummer method before it was added into TiO2. The formation of GO from it graphite precursor had been confirmed by Raman spectroscopy. The existence of D-band at wavelength of 1328 cm-1 and G-band at 1573 cm-1 shows the formation of GO. The GO was then added in different concentration; 0.0 - 1.0 wt% into TiO2. The photocatalytic activity was determined using calculating the photodegradation efficiencies of methylene blue under UV light irradiation. The experimental results showed that the photodegradation of MB were increased with higher dopants concentration due to reduction of band gap energy of TiO2 from 3.2 eV to 3.0 eV for 1.0 wt% GO-with the photodegradation efficiency of GO doped TiO2 was 61.38%.

The Nanocrystallinity Enhancement and Optical Characteristics of Pre-Hydrothermally Treated ZnO Nanoparticles

2012 ◽  
Vol 557-559 ◽  
pp. 468-471 ◽  
Author(s):  
Akhmad Herman Yuwono ◽  
Ghiska Ramahdita ◽  
Nofrijon Sofyan
Keyword(s):  
Band Gap ◽  
Crystallite Size ◽  
Hydrothermal Treatment ◽  
Zno Nanoparticles ◽  
Treatment Duration ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Nanocrystallite Size ◽  
Gel Technique

In the current research, ZnO nanoparticles have been synthesized via sol-gel technique assisted by a pre-hydrothermal treatment at 150oC with various holding time of 0, 24, 48 and 72 hours. This route was specifically aimed at investigating the effect of this treatment on the nanocrystallite size, crystallinity and band gap energy of the resulting nanoparticles. The results of investigation showed that an increasing of pre-hydrothermal treatment duration from 0 to 72 hours has increased the crystallite size of ZnO nanoparticles from 3.47 to 13.85 nm, and decreased the band gap energy from 3.10 to 3.08 eV.

scholarly journals SYNTHESIS OF Fe2O3-MONTMORILLONITE AND ITS APPLICATION AS A PHOTOCATALYST FOR DEGRADATION OF CONGO RED DYE

2010 ◽  
Vol 5 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Karna Wijaya ◽  
Iqmal Tahir ◽  
Nanik Haryanti
Keyword(s):  
Congo Red ◽  
Diffuse Reflectance ◽  
Uv Light ◽  
Band Gap Energy ◽  
Comparison Result ◽  
X Ray ◽  
Gap Energy ◽  
Congo Red Dye ◽  
Uv Illumination ◽  
Red Dye

The preparation of Fe2O3-montmorillonite and it's application as a catalyst for congo red dye photodegradation has been carried out. Fe2O3-montmorillonite was prepared by mixing the iron complexes pillaring agent and montmorillonite. The product was calcined at 250 oC for 5 hours. Montmorillonite and calcined product was analyzed by X-ray diffractometry (X-RD), infrared spectrophotometry (FTIR), gas  sorption analyser, X-ray fluorescense (X-RF) and UV/Vis diffuse reflectance spektrophotometry (UV-DRS). Fe2O3-montmorilonite then was used as a catalyst on congo red dye photodegrdation by UV-illuminating a mixture of 50 mg Fe2O3-montmorillonite and 25 mL congo red 10­-4M at 365 nm at various illuminating times. Adsorption of congo red on Fe2O3-montmorillonite and montmorillonite was also performed as a comparison. Result of X-RD analysis showed that the 001 reflection of  Fe2O3-montmorillonite was not  detected that probably indicating the formation of house of card stucture and this result was supported also by the analysis result of distribution of pores and SEM photography result. Results of the XRF analysis showed that iron content increased  from 5.21 % (w/w) in montmorillonite to 25.12 % (w/w) in Fe2O3-montmorillonite. UV- DRS analysis showed the increament of band gap energy from 3.69 eV in the iron oxide bulk to 3.8 eV in Fe2O3-montmorillonite. Specific surface area of the montmorillonite also increased significantly from 69,71 m2/g to 126,49 m2/g and total pores volume increased from 50.70x10-3 mL/Å/g  to 107.89x10-3 mL/Å/g, respectively. Photodegradation of congo red using Fe2O3-montmorillonite caused the decreament of congo red concentration up to 90.22 %  on UV illumination for 60 minutes. Adsorption of congo red on Fe2O3-montmorillonite reached 84.4% and on  montmorillonite was 75.15 %.   Keywords: photodegradation, congo red, Fe2O3-montmorillonite, UV light

scholarly journals Enhanced photocatalytic degradation of N-doped TiO2-SiO2 composite for degradation of phenol under simulated natural light assisted by S2O8 2- anions

2021 ◽  
Vol 947 (1) ◽  
pp. 012020
Author(s):  
Huu-Tai Huynh ◽  
Minh-Vien Le ◽  
Luan Van Hoang
Keyword(s):  
Photocatalytic Degradation ◽  
Band Gap ◽  
Rate Constant ◽  
Degradation Rate ◽  
Band Gap Energy ◽  
Natural Light ◽  
Doped Tio2 ◽  
Gap Energy ◽  
Molar Ratios ◽  
Degradation Rate Constant

Abstract In recent years, TiO2 photocatalyst has been studied to increase the overall efficiency in the degradation of organic pollutants in water. Several solutions have been proposed such as non-metal doping to reduce a high band gap energy (3.2 eV) of TiO2 to increase absorption in the visible region and synthesis of composite photocatalyst to improve the efficiency of electron-hole separation and the specific surface area. Herein, the N-doped TiO2-SiO2 photocatalysts were investigated. Powder samples with three molar ratios of TiO2/SiO2 (95/5-TS5, 85/15-TS15, 75/25-TS25) were successfully synthesized, characterized, and estimated their photocatalytic activity toward the phenol degradation (initial concentration to be 10 ppm) under simulated natural light. N-doped TiO2-SiO2 samples were prepared with molar ratios of N to designed TiO2 to be 3%, 5%, 7%. The 3N-TS5 photocatalyst (3 mol % N doped TS5) shows the highest phenol efficiency degradation, to be 95% in 4 h, photocatalytic degradation rate constant of 1.02}10−2 min−1 due to its narrower band gap energy (3.05 eV). Furthermore, the addition of S2O8 2- anions at a concentration of 1 mM is enhanced degradation efficiency and degradation rate. And phenol is almost completely degraded within 60 min and achieved a degradation rate constant of 7.65*10−2 min−1, 7.5 times higher than that without the presence of S2O8 2- anions. This attractive result is attributed to the generation of sulfate radical (SO4 *“) during photolysis. Finally, N-doped TiO2-SiO2 photocatalyst assisted by S2O8 2- anions shows potential to design and improve manufacturing processes to obtain photoreactors for organic degradation from waste-water under natural light degradation.

scholarly journals The Photocatalytic Activity of Zns-TiO2 on a Carbon Fiber Prepared by Chemical Bath Deposition

2019 ◽  
Vol 17 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Fitria Rahmawati ◽  
Fatmawati R. Putri ◽  
Abu Masykur
Keyword(s):  
Photocatalytic Activity ◽  
Carbon Fiber ◽  
Chemical Bath Deposition ◽  
Uv Light ◽  
Light Response ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Interface Charge ◽  
C Fiber ◽  
Isopropanol Solution

AbstractThis research prepared a TiO2, ZnS, and ZnS-TiO2 film on a carbon fiber, to produce TiO2/C-fiber, ZnS-C-fiber, and ZnS-TiO2/C-fiber by Chemical Bath Deposition (CBD). Results show that TiO2/C-fiber consist of anatase at 2θ 25.3 o and 54.6 o, rutile at 2θ 43.5 o and a carbon characteristic peak at 2θ of 24.5 o. Meanwhile, the characteristic peaks of ZnS on ZnS-TiO2/C-fiber present at 2θ of 27.91 o and 54.58 o. TiO2/C-fiber has a band gap energy of 3.60 eV, the ZnS/C-fiber of 3.73 eV; when those two catalyst combine, the gap energy is 3.15 eV indicating the interface charge transfer between ZnS-TiO2. Photocatalytic treatment of an isopropanol solution with TiO2/C-fiber as a catalyst and under UV light radiation present results peaks at 222- 224 nm and 265 nm, indicating the electronic transition of acetone. Meanwhile, the isopropanol degradation with ZnS-TiO2/C-fiber produced a new peak at 234-237 nm. The Quantum Yield, QY, of ZnS-TiO2/C-fiber is 6.96 x 10-4, higher than TiO2/C-fiber, i.e., 0.42 x 10-4. It indicates that ZnS provides a significant role in the photocatalytic activity through a red shift of light response and decreasing electron-hole recombination.

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