scholarly journals Photocatalytic Degradation of Rhodamine B Dye in Aqueous Suspension by ZnO and M-ZnO (M = La3+, Ce3+, Pr3+ and Nd3+) Nanoparticles in the Presence of UV/H2O2

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1736
Author(s):  
José C. González-Crisostomo ◽  
Rigoberto López-Juárez ◽  
Vitalii Petranovskii
Keyword(s):  
Rhodamine B ◽  
Dye Degradation ◽  
Aqueous Suspension ◽  
Kinetic Mechanism ◽  
Degradation Efficiency ◽  
Rare Earth Ions ◽  
Order Kinetic ◽  
Secondary Phases ◽  
Pure Zinc ◽  
Ultraviolet Illumination

In this study, nanoparticles of five photocatalytic systems based on pure zinc oxide and with rare earths ions M-ZnO (M = La3+, Ce3+, Pr3+ or Nd3+) calcined at 500 °C or 700 °C were synthesized and investigated as potential photocatalysts for the removal of dyes. The addition of rare earth ions causes a decrease in the bandgap of ZnO; therefore, it can be well used to improve the photocatalytic properties. The photocatalytic activity of the synthesized nanoparticles was evaluated by the degradation of Rhodamine B in the presence of H2O2 under ultraviolet illumination. The results indicate that all the synthesized nanoparticles show good dye degradation efficiency. The highest degradation efficiency was 97.72% for the Ce-ZnO sample calcined at 500 °C and was achieved in 90 min with an excellent constant of the dye degradation rate k = 0.0363 min−1 following a first-order kinetic mechanism. The presence of oxychlorides as secondary phases inhibits the rate of the photocatalytic reaction.

Immobilization of Nano-TiO2 on Expanded Perlite for Photocatalytic Degradation of Rhodamine B

2011 ◽  
Vol 110-116 ◽  
pp. 3795-3800 ◽  
Author(s):  
Xiao Zhi Wang ◽  
Wei Wei Yong ◽  
Wei Qin Yin ◽  
Ke Feng ◽  
Rong Guo
Keyword(s):  
Catalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Degradation Kinetics ◽  
Irradiation Time ◽  
Sol Gel ◽  
Polluted Water ◽  
Order Kinetic ◽  
Expanded Perlite ◽  
Initial Concentration

Expanded perlite (EP) modified titanium dioxide (TiO2) with different loading times were prepared by Sol-Gel method. Photocatalytic degradation kinetics of Rhodamine B (RhB) in polluted water by the materials (EP-nanoTiO2), as well as the effects of different loading times and the initial concentration of RhB on photocatalysis rate were examined. The catalytic activity of the regenerated photocatalyst was also tested. The results showed that photocatalyst modified three times with TiO2had the highest catalytic activity. Degradation ratio of RhB by EP-nanoTiO2(modified three times) under irradiation for 6 h were 98.0%, 75.6% and 63.2% for 10 mg/L, 20 mg/L and 30 mg/L, respectively.The photocatalyst activity has little change after the five times recycling, and the degradation rate of RhB decreased less than 8%. The reaction of photocatalysis for RhB with irradiation time can be expressed as first-order kinetic mode within the initial concentration range of RhB between 10mg/L and 30 mg/L. EP-nanoTiO2photocatalyst has a higher activity and stability to degrade RhB in aqueous solution.

Preparation of cationic waste paper and its application in poisonous dye removal

2013 ◽  
Vol 67 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Fan Yang ◽  
Xiaojie Song ◽  
Lifeng Yan
Keyword(s):  
Low Cost ◽  
Aqueous Suspension ◽  
Order Kinetic ◽  
Acid Orange 7 ◽  
Anionic Dyes ◽  
Experimental Conditions ◽  
Adsorption Models ◽  
Acid Orange ◽  
Initial Ph ◽  
Pseudo Second Order

Cationic paper was prepared by reaction of paper with 2,3-epoxypropyltrimethylammonium chloride in aqueous suspension, and tested as low-cost adsorbent for wastewater treatment. The experimental results revealed that anionic dyes (Acid Orange 7, Acid Red 18, and Acid Blue 92) were adsorbed on the cationic paper nicely. The maximum amount of dye Acid Orange 7 adsorbed on cationic paper was 337.2 mg/g in experimental conditions. The effects of initial dye concentration, temperature, and initial pH of dye solution on adsorption capacity of cationic paper were studied. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data. The Freundlich and Langmuir adsorption models were used to describe adsorption equilibrium. The thermodynamic data indicated that the adsorption process of dye on cationic paper occurred spontaneously.

Comparison of dye degradation efficiency using ZnO powders with various size scales

2007 ◽  
Vol 141 (3) ◽  
pp. 645-652 ◽  
Author(s):  
H WANG ◽  
C XIE ◽  
W ZHANG ◽  
S CAI ◽  
Z YANG ◽  
...  
Keyword(s):  
Dye Degradation ◽  
Degradation Efficiency ◽  
Zno Powders ◽  
Size Scales

scholarly journals Palladium-Supported Zirconia-Based Catalytic Degradation of Rhodamine-B Dye from Wastewater

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1522
Author(s):  
Salma Jabeen ◽  
Muhammad Sufaid Khan ◽  
Rozina Khattak ◽  
Ivar Zekker ◽  
Juris Burlakovs ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rhodamine B ◽  
Dye Degradation ◽  
Freundlich Isotherm ◽  
Impregnation Method ◽  
K Value ◽  
First Order Kinetics ◽  
Good Catalytic Activity ◽  
Rhodamine B Dye ◽  
Best Fit

The catalytic activity of Pd/ZrO2 was studied in terms of the degradation of rhodamine-B dye in the presence of hydrogen peroxide. Pd/ZrO2 was prepared by impregnation method, calcined at 750 °C and characterized by XRD, SEM and EDX. The catalyst showed good catalytic activity for dye degradation at 333 K, using 0.05 g of the catalyst during 5 h. The reaction kinetics followed the pseudo-first order kinetics. The Freundlich, Langmuir and Temkin isotherms were applied to the data and the best fit was obtained with Freundlich isotherm. Thermodynamic parameters, like ΔH, ΔG and ΔS were also calculated. The negative values of ΔH (−291.406 KJ/mol) and Gibbs free energy (ΔG) showed the exothermic and spontaneous nature of the process. The positive ΔS (0.04832 KJ/mol K) value showed suitable affinity of catalyst for dye degradation. The catalyst was very stable, active and was easily separated from the reaction mixture by filtration. It can be concluded from the results that the prepared catalyst could be effectively used in dyes degradation/removal from water subjected to further validation and use for various dyes.

Structure, morphology features and photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite clay

2021 ◽  
Vol 02 ◽  
Author(s):  
Amanda Carolina Soares Jucá ◽  
Francisco Henrique Pereira Lopes ◽  
Herbert Vieira Silva-Júnior ◽  
Lara Kelly Ribeiro Silva ◽  
Elson Longo ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Rhodamine B ◽  
Dye Degradation ◽  
Degradation Kinetics ◽  
Low Cost ◽  
Catalytic Efficiency ◽  
Photocatalytic Properties ◽  
Impregnation Method ◽  
Heat Treated ◽  
Modified Palygorskite

Aims: In the present study, we investigate the photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite (PAL) clay synthesized by the impregnation method. The PAL clay was chemically purified and heat-treated (500 ºC for 2 h), which served as an excellent supporting matrix for loading α-Ag2WO4(α-AWO) nanocrystals. Background: Water contamination is one of the most serious problems affecting human health, ecosystem survival, and the economic growth of societies. Industrial effluents, such as textile dyes, when not treated and improperly discharged into water resources are considered the main cause of water pollution. Thus the scientific community has been developing effective remediation technologies based on advanced oxidative processes to reduce the harmful effects of these organic pollutants. Objective: Improve the photocatalytic activity of PAL clay with α-AWO nanocrystals to degradation of Rhodamine B (RhB) dye. Methods: We purify and heat-treated the PAL clay, synthesize nanocrystals ofα-AWO nanocrystals and modify PAL clay with 30% α-AWO nanocrystals by the impregnation method. The modified PAL clay was able to improve RhB dye degradation. The materials were characterized by XRD, RAMAN,FE-SEM, FT-IR, XRF, etc. The samples were used as photocatalysts under UV-C lamps for the degradation of RhB dye in order to analyze its catalytic performances. Results: ThePAL clay modified with 30% α-AWO nanocrystals showed a catalytic efficiency of 79%, and degradation kinetics about 16 times higher when compared to PAL-500 only purified and heat-treated at 500 ºC. In this way, this PAL-modified is an alternative as a low-cost photocatalyst for the degradation of RhB dye. Conclusion: Ultraviolet-Visiblespectra revealed that our materials have opticalband gap energies controlled by indirect and direct electronic transitions and suitable to be activated under ultraviolet illumination. The adequate amount (30 wt.%) of α-Ag2WO4 nanocrystals added to PAL brought significant improvement of photocatalytic activity for the degradation of rhodamine B. Finally, a photocatalytic mechanism was proposed in detail.

scholarly journals Fast and Effective Catalytic Degradation of an Organic Dye by Eco-friendly Capped ZnS and Mn doped ZnS nanocrystals

2021 ◽  
Author(s):  
Sabri Ouni ◽  
Naim Bel Haj Mohamed ◽  
Noureddine Chaaben ◽  
Adrian Bonilla-Petriciolet ◽  
Mohamed Haouari
Keyword(s):  
Statistical Physics ◽  
Thioglycolic Acid ◽  
Dye Degradation ◽  
Low Cost ◽  
Quantum Confinement Effect ◽  
Dye Adsorption ◽  
Blue Shift ◽  
Order Kinetic ◽  
Zns Nanocrystals ◽  
Mn Doped

Abstract Undoped and Mn-doped ZnS nanocrystals encapsulated with thioglycolic acid were synthetized and characterized with different techniques, and finally tested in the photodegradation of a methyl orange in aqueous solution under UV and sunlight irradiations. FTIR and X-ray diffraction results confirmed the functionalization of these nanocrystals surface by thioglycolic acid and the formation of crystalline structures of ZnS and Mn-doped ZnS with cubic and hexagonal phases. Calculated average size of ZnS nanocrystals was in the range of 2 - 3 nm. It was observed a blue shift of the absorbance threshold and the estimated bandgap energies were higher than that of Bulk ZnS thus confirming the quantum confinement effect of charge carriers. Photoluminescence spectra of ZnS nanocrystals exhibited emission in the range of 410- 490 nm and the appearance of an additional emission band around 580 nm (2.13eV) connected to the 4𝑇1→ 6𝐴1 transition of the Mn2+ions. Photodegradation of methylene orange with undoped and Mn-doped ZnS-TGA nanocrystals was investigated. Dye adsorption prior to photocatalysis using nanocrystals was studied via kinetic experiments and statistical physics models. The maximum dye adsorption capacity on doped ZnS-TGA was ~ 26.98 mg/g. The adsorption kinetic was found to follow the pseudo-second-order kinetic model.According to the statistical physics results, the calculated adsorption energy was 22.47-23.47 kJ/mol and it showed that the dye adsorption was associated to the hydrogen interaction where the removal process was feasible and multi-molecular. The photocatalytic activity of undoped ZnS nanoparticles under UV irradiation showed better efficiency than doped nanocrystals thus indicating that manganese doping generated a dropping of the photocatalytic degradation of the dye. Dye degradation efficiency of 81.37% using ZnS-TGA nanocrystals was achieved after 6 min, which indicated that ZnMnS-TGA nanocrystals may be considered as an alternative low cost and environmental friendly material for facing water pollution caused by organic compounds via photodegradation processes.

Green synthesis, structural characterization, and catalytic activity of silver nanoparticles stabilized with Bridelia retusa leaf extract

2018 ◽  
Vol 7 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Ramesh Vinayagam ◽  
Thivaharan Varadavenkatesan ◽  
Raja Selvaraj
Keyword(s):  
Silver Nanoparticles ◽  
Rhodamine B ◽  
Leaf Extract ◽  
Dye Degradation ◽  
Synthesis Method ◽  
Degradation Process ◽  
Spectroscopic Studies ◽  
Metallic Silver ◽  
X Ray ◽  
Bridelia Retusa

Abstract:An environmentally benign method to synthesize silver nanoparticles (SNPs) using the leaf extract ofBridelia retusawas developed. The UV-Vis absorption spectrum of the synthesized SNPs displayed a surface plasmon peak at 420 nm. Scanning electron microscopy (SEM) revealed the irregular shaped nanoparticles, and energy dispersive X-ray (EDX) ascertained the presence of metallic silver by showing a strong signal at 3 eV. The crystalline structure of metallic silver was confirmed by X-ray diffraction (XRD). The mean size of the SNPs was calculated as 16.21 nm. Fourier infrared (FT-IR) spectroscopic studies displayed specific bands for various functional groups and affirmed the function of reduction and stabilization of SNPs. The stability was endorsed by the zeta potential value of −18.1 mV. The results evidenced that this leaf extract-mediated synthesis method is eco-friendly, rapid, and cheap. The catalytic power of the SNPs was investigated for Rhodamine B dye degradation. The SNPs completely degraded Rhodamine B within 9 min; thus, the dye degradation process was very rapid. The pseudo-first order degradation constant was found out to be 0.1323 min−1. This paves the way for the future development of novel nano-catalysts to reduce environmental pollution.

scholarly journals Fabrication of novel particle electrode γ-Al2O3@ZIF-8 and its application for degradation of Rhodamine B

2019 ◽  
Vol 80 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Liguo Zhang ◽  
Caixia Ma ◽  
Lei Liu ◽  
Jingshi Pan ◽  
Qilin Wang
Keyword(s):  
Surface Area ◽  
Removal Efficiency ◽  
Rhodamine B ◽  
Three Dimensional ◽  
Cell Voltage ◽  
Bet Surface Area ◽  
Order Kinetic ◽  
Zeolitic Imidazolate Framework ◽  
Crystallization Method ◽  
Order Kinetic Model

Abstract Due to the high Brunauer–Emmett–Teller (BET) surface area of zeolitic imidazolate framework (ZIF)-8, a secondary crystallization method was used to prepare a particle electrode of γ-Al2O3@ZIF-8. According to the results from a field emission scanning electron microscope (SEM) and X-ray diffractometer (XRD), the particle electrode of γ-Al2O3 was successfully loaded with ZIF-8, and the BET surface area (1,433 m2/g) of ZIF-8 was over ten times that of γ-Al2O3. The key operation parameters of cell voltage, pH, initial RhB concentration and electrolyte concentration were all optimized. The observed rate constant (kobs) of the pseudo-first-order kinetic model for the electrocatalytic oxidation (ECO) system with the particle electrode of γ-Al2O3@ZIF-8 (15.2 × 10−2 min−1) was over five times higher than that of the system with the traditional particle electrode of γ-Al2O3 (2.6 × 10−2 min−1). The loading of ZIF-8 on the surface of γ-Al2O3 played an important role in improving electrocatalytic activity for the degradation of Rhodamine B (RhB), and the RhB removal efficiency of the three-dimensional (3D) electrocatalytic system with the particle electrode of γ-Al2O3@ZIF-8 was 93.5% in 15 min, compared with 27.5% in 15 min for the particle electrode of γ-Al2O3. The RhB removal efficiency was kept over 85% after five cycles of reuse for the 3D electrocatalytic system with the particle electrode of γ-Al2O3@ZIF-8.

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