Photocatalytic Degradation of Methylene Blue by the La-N/TiO2 Composite and its Kinetic Enumeration

2017 ◽  
Vol 863 ◽  
pp. 20-25 ◽  
Author(s):  
Jing Li Gao ◽  
Ying Hui Han ◽  
Yu Juan Li ◽  
Xiao Hong Zhang
Keyword(s):  
Methylene Blue ◽  
Composite Material ◽  
Kinetic Model ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Synergistic Effects ◽  
Kinetic Mechanism ◽  
Order Kinetic ◽  
Doping Amount ◽  
Preparation Conditions

Photocatalytic degradation kinetics of methylene blue in aqueous solution was systematically investigated using Ti-based composite material as the photocatalyst. The single-variable-at-a-time ( SVAT) method was employed. It studied the individual and synergistic effects of several classical parameters on photocatalytic efficiencies. The kinetic mechanism was systematically explored. The kinetics effects of the doping amount of La and N, calcination temperature and time, light intensity were studied in detail. The factors on the degradation of MB were in accordance with the pseudo first order kinetic model. This kinetic model followed the Langmuir–Hinshelwood model. The best preparation conditions were found in the experiments. It is proved that the Ti-based composite material is an effective adsorbent for the degradation of dye contaminated water.

Synthesis, Characterization and Photocatalytic Activity of La2O3-N/TiO2 for Methylene Blue Removal under UV Irradiation

2017 ◽  
Vol 863 ◽  
pp. 53-58
Author(s):  
Jing Li Gao ◽  
Ying Hui Han ◽  
Yu Juan Li ◽  
Xiao Hong Zhang
Keyword(s):  
Methylene Blue ◽  
Composite Material ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Molar Ratio ◽  
Future Research ◽  
The Novel ◽  
Doping Amount ◽  
Preparation Conditions ◽  
Optimal Material

In this work, the novel Ti-based composite material has been synthesized, characterized and studied for the photocatalytic degradation of methylene blue(MB). The effects of the doping amount of La and N, calcination temperature and time, light intensity were studied in detail. The strong synergism of La, N and TiO2 was discussed during the photocatalytic process. The results suggested that the degradation efficiency was obviously improved by the Ti-based photocatalyst and the La element could enhance the photocatalytic degradation performance significantly, and the best molar ratio of N and TiO2 was 0.000014:1. The study found that the best preparation conditions can also improve the photocatalytic activity, the optimal material was made after calcining for 4h at 800°C. What is more, the higher illumination power was benifit for the degradation of the MB. It is indicated that the mixed crystal Ti-based composite material being an effective adsorbent for the elimination of the contaminated water by dyes. In addition, the work provide new direction for future research.

scholarly journals Green Synthesis of Nano Zinc Oxide/Nanohydroxyapatite Composites Using Date Palm Pits Extract and Eggshells: Adsorption and Photocatalytic Degradation of Methylene Blue

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 49
Author(s):  
Maha S. Elsayed ◽  
Inas A. Ahmed ◽  
Dina M. D. Bader ◽  
Asaad F. Hassan
Keyword(s):  
Methylene Blue ◽  
Zinc Oxide ◽  
Kinetic Model ◽  
Photocatalytic Degradation ◽  
Date Palm ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Nano Zinc Oxide ◽  
Order Kinetic Model ◽  
Nano Zinc

In this study, zinc oxide nanoparticles (ZnO) and nanohydroxyapatite (NHAP) were prepared in the presence of date palm pits extract (DPPE) and eggshells, respectively. Another four nanocomposites were prepared from ZnO and NHAP in different ratios (ZP13, ZP14, ZP15, and ZP16). DPPE and all nanomaterials were characterized using GC-MS, zeta potentials, particle size distributions, XRD, TEM, EDX, FTIR, and pHPZC. The characterization techniques confirmed the good distribution of ZnO nanoparticles on the surface of NHAP in the prepared composites. Particles were found to be in the size range of 42.3–66.1 nm. The DPPE analysis confirmed the presence of various natural chemical compounds which act as capping agents for nanoparticles. All the prepared samples were applied in the adsorption and photocatalytic degradation of methylene blue under different conditions. ZP14 exhibited the maximum adsorption capacity (596.1 mg/g) at pH 8, with 1.8 g/L as the adsorbent dosage, after 24 h of shaking time, and the static adsorption kinetic process followed a PSO kinetic model. The photocatalytic activity of ZP14 reached 91% after 100 min of illumination at a lower MB concentration (20 mg/L), at pH 8, using 1.5 g/L as the photocatalyst dosage, at 25 °C. The photocatalytic degradation of MB obeyed the Langmuir–Hinshelwood first-order kinetic model, and the photocatalyst reusability exhibited a slight loss in activity (~4%) after five cycles of application.

scholarly journals Investigation of Seeds and Peels of Citrullus colocynthis as Efficient Natural Adsorbent for Methylene Blue Dye

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1279
Author(s):  
Wafa Mohammed Alghamdi ◽  
Ines El Mannoubi
Keyword(s):  
Methylene Blue ◽  
Kinetic Model ◽  
Langmuir Isotherm ◽  
Order Kinetic ◽  
Citrullus Colocynthis ◽  
Natural Adsorbent ◽  
Spontaneous Process ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Mb Adsorption

Natural adsorbents as low-cost materials have been proved efficient for water remediation and have significant capacity for the removal of certain chemicals from wastewater. The present investigation aimed to use Citrullus colocynthis seeds (CCSs) and peels (CCPs) as an efficient natural adsorbent for methylene blue (MB) dye in an aqueous solution. The examined biosorbents were characterized using surface area analyzer (BET), scanning electron microscope (SEM), thermogravimetric analyzer (TGA) and Fourier transform infra-red (FT-IR) spectroscopy. Batch adsorption experiments were conducted to optimize the main factors influencing the biosorption process. The equilibrium data for the adsorption of MB by CCSs were best described by the Langmuir isotherm followed by the Freundlich adsorption isotherms, while the equilibrium data for MB adsorption by CCPs were well fitted by the Langmuir isotherm followed by the Temkin isotherm. Under optimum conditions, the maximum biosorption capacity and removal efficiency were 18.832 mg g−1 and 98.00% for MB-CCSs and 4.480 mg g−1 and 91.43% for MB-CCPs. Kinetic studies revealed that MB adsorption onto CCSs obeys pseudo-first order kinetic model (K1 = 0.0274 min−1), while MB adsorption onto CCPs follows the pseudo-second order kinetic model (K2 = 0.0177 g mg−1 min−1). Thermodynamic studies revealed that the MB biosorption by CCSs was endothermic and a spontaneous process in nature associated with a rise in randomness, but the MB adsorption by CCPs was exothermic and a spontaneous process only at room temperature with a decline in disorder. Based on the obtained results, CCSs and CCPSs can be utilized as efficient, natural biosorbents, and CCSs is promising since it showed the highest removal percentage and adsorption capacity of MB dye.

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.

scholarly journals Photocatalytic degradation kinetics of Orange G dye over ZnO and Ag/ZnO thin film catalysts

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Derya Tekin ◽  
Taner Tekin ◽  
Hakan Kiziltas
Keyword(s):  
Thin Film ◽  
Kinetic Model ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Reaction Medium ◽  
Rate Equations ◽  
Zno Thin Film ◽  
Model Studies ◽  
Thin Film Catalysts ◽  
Orange G

AbstractThe degradation of water pollutants with photocatalysts is one of the most studied subjects in the past 20 years. Although considerable studies have been completed in this field, kinetic model studies are still a major inadequacy. In this study, ZnO and Ag/ZnO thin film photocatalysts were synthesized and SEM-EDS, XRD and chronoamperometric measurements were used the characterization of photocatalysts. The network kinetic model was applied the photocatalytic degradation of Orange G using ZnO and Ag/ZnO thin film photocatalysts. The photocatalytic degradation of Orange G was investigated under the different reaction medium (initial dye concentrations, temperature, light intensity). It was found that the network kinetic model is the most appropriate model for the degradation of Orange G dye on the ZnO and Ag/ZnO thin film photocatalysts. The calculated adsorption equilibrium (KB) constant and activation energy of ZnO thin film photocatalyst are 0.0191 and 21.76 kj/mol, respectively. Additionally, the calculated values for Ag/ZnO thin film photocatalyst are 0.035 and 18.32 kj/mol. The general rate equations were determined for each photocatalysts.

The Photocatalytic Degradation of Methylene Blue Wastewater with Nanoscale Ferric Oxide as Catalyst

2011 ◽  
Vol 356-360 ◽  
pp. 1813-1818
Author(s):  
Yi Ren Zhu ◽  
Guang Chao Li ◽  
Qian Ping Zhang ◽  
Chong Tang
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Light Source ◽  
High Voltage ◽  
Ferric Oxide ◽  
Ph Value ◽  
Order Kinetic ◽  
Mercury Lamp ◽  
Excitation Light ◽  
Simulated Wastewater

Nanoscale Ferric Oxide was prepared from natural hematite and characterized. Using it as catalyst, methylene blue-simulated wastewater was treated by photocatalytic degradation with high-voltage mercury lamp and sunlight as excitation light source. Main factors, including the preparation conditions and dosage of ferric oxide, pH value, reaction time and initial concentration of simulated wastewater, and their influence to treatment effect were discussed. Test results showed that at a pulverization time of 1.5h, calcination time of 2h at 500°C, initial methylene blue (MB) concentration of 20mg/L, pH=2 and a ferric oxide dosage of 0.01g/30ml, for both high-voltage mercury lamp and sunlight, MB wastewater was degraded effectively in lab-scale experiment; after 5h’s radiation, MB concentrations were reduced from 20mg/L to 0.51mg/L and 9.18mg/L respectively. With sunlight as the radiation light source, an enlarged experiment was done on a custom-built device, and MB concentration was reduced from 20mg/L to 0.11mg/L, which was significantly better than treatment results from lab-scale experiments and UV radiation. MB photocatatytic degradation reactions at different initial concentrations were in accordance with Lagergren’s pseudo-first-order kinetic equation. Spectral analysis of degradation products showed that MB molecules were degraded to inorganic ions.

Synthesis and characterization of anatase TiO2 nanolayer coating on Ni–Cu–Zn ferrite powders for magnetic photocatalyst

2010 ◽  
Vol 25 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Yen-Pei Fu ◽  
Wen-Ku Chang ◽  
Hsin-Chao Wang ◽  
Chung-Wen Liu ◽  
Cheng-Hsiung Lin
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Degradation Efficiency ◽  
Ferrite Powder ◽  
Order Kinetic ◽  
Magnetic Photocatalyst ◽  
The Core ◽  
Zn Ferrite

In the current research, we successfully prepared TiO2/Ni–Cu–Zn ferrite composite powder for magnetic photocatalyst. The core Ni–Cu–Zn ferrite powder was synthesized using the steel pickling liquor and the waste solution of electroplating as the starting materials. The shell TiO2 nanocrystal was prepared by sol-gel hydrolysis precipitation of titanium isopropoxide [Ti(OC3H7)4] on the Ni–Cu–Zn ferrite powder followed by heat treatment. From transmission electron microscopy (TEM) image, the thickness of the titania shell was found to be approximately 5 nm. The core of Ni–Cu–Zn ferrite is spherical or elliptical shape, and the particle size of the core is in the range of 70–110 nm. The magnetic Ni–Cu–Zn ferrite nanopowder is uniformly encapsulated in a titania layer forming core-shell structure of TiO2/Ni–Cu–Zn ferrite powder. The degradation efficiency for methylene blue (MB) increases with magnetic photocatalyst (TiO2/Ni–Cu–Zn ferrite powder) content. When the magnetic photocatalyst content is 0.40 g in 150 mL of MB, the photocatalytic activity reached the largest value. With a further increase in the content of magnetic photocatalyst, the degradation efficiency slightly decreased. This occurs because the ultraviolet (UV) illumination is covered by catalysts, which were suspended in the methylene blue solution and resulted in the inhibition in the photocatalytic reaction. The photocatalytic degradation result for the relationship between MB concentration and illumination revealed a pseudo first-order kinetic model of the degradation with the limiting rate constant of 1.717 mg/L·min and equilibrium adsorption constant 0.0627 L/mg. Furthermore, the Langmuir–Hinshelwood model can be used to describe the degradation reaction, which suggests that the rate-determining step is surface reaction rather than adsorption is in photocatalytic degradation.

scholarly journals Synthesis of Porous Material from Coal Gasification Fine Slag Residual Carbon and Its Application in Removal of Methylene Blue

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6116
Author(s):  
Yixin Zhang ◽  
Rumeng Wang ◽  
Guofeng Qiu ◽  
Wenke Jia ◽  
Yang Guo ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Kinetic Model ◽  
Porous Material ◽  
Coal Gasification ◽  
Raw Material ◽  
Maximum Adsorption Capacity ◽  
Residual Carbon ◽  
Order Kinetic ◽  
Activation Temperature ◽  
Foam Flotation

A large amount of coal gasification slag is produced every year in China. However, most of the current disposal is into landfills, which causes serious harm to the environment. In this research, coal gasification fine slag residual carbon porous material (GFSA) was prepared using gasification fine slag foam flotation obtained carbon residue (GFSF) as raw material and an adsorbent to carry out an adsorption test on waste liquid containing methylene blue (MB). The effects of activation parameters (GFSF/KOH ratio mass ratio, activation temperature, and activation time) on the cation exchange capacity (CEC) of GFSA were investigated. The total specific surface area and pore volume of GSFA with the highest CEC were 574.02 m2/g and 0.467 cm3/g, respectively. The degree of pore formation had an important effect on CEC. The maximum adsorption capacity of GFSA on MB was 19.18 mg/g in the MB adsorption test. The effects of pH, adsorption time, amount of adsorbent, and initial MB concentration on adsorption efficiency were studied. Langmuir isotherm and quasi second-order kinetic model have a good fitting effect on the adsorption isotherm and kinetic model of MB.

scholarly journals Removal Study of Crystal Violet and Methylene Blue From Aqueous Solution by Activated Carbon Embedded Zero-Valent Iron: Effect of Reduction Methods

2021 ◽  
Vol 9 ◽  
Author(s):  
Yongmei Wang ◽  
Tiantian Chen ◽  
Xiaolin Zhang ◽  
Teza Mwamulima
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Kinetic Model ◽  
Specific Surface ◽  
Surface Area ◽  
Crystal Violet ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Order Kinetic Model

Zero valent iron (ZVI) particles were embedded into porous materials to avoid aggregation and separation problems in the controlled synthesis process. To investigate the adsorption mechanism of crystal violet and methylene blue, activated carbon (AC) and AC-based ZVI extraction by solid-phase and liquid-phase reduced approaches was conducted. Characterization methods of specific surface area, scanning electron microscopy (SEM), and x-ray diffractograms (XRD) were used to elucidate the structure of adsorbents, and the adsorption capacities of crystal violet and methylene blue were obtained under experimental conditions of various pH values (2.0–10.0), adsorption times (0–72 h), and temperatures (30–50°C). The adsorption of crystal violet/methylene blue was controlled by both chemisorption and reduction. The adsorption processes were fitted to a pseudo-second-order kinetic model, and that of reduction kinetics was suitable to pseudo-first-order kinetic model. The thermodynamic study revealed that the adsorption of crystal violet and methylene blue was endothermic and spontaneous, and the adsorption isotherms fitted well to the Langmuir model. Different adsorption capacities of crystal violet and methylene blue on various adsorbents were found, indicating that both the properties of adsorbents (pore size, specific surface area, and chemical functional groups) and the structures of adsorbates had significant effect on the removal of dye molecules.

scholarly journals Preparation and Characterization of Magadiite–Magnetite Nanocomposite with Its Sorption Performance Analyses on Removal of Methylene Blue from Aqueous Solutions

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 607 ◽  
Author(s):  
Mingliang Ge ◽  
Zhuangzhuang Xi ◽  
Caiping Zhu ◽  
Guodong Liang ◽  
Guoqing Hu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Aqueous Solutions ◽  
Langmuir Adsorption Isotherm ◽  
Order Kinetic ◽  
Langmuir Adsorption ◽  
Adsorption Performance ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The magadiite–magnetite (MAG–Fe3O4) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe3O4 and the high adsorption capacity of pure magadiite (MAG). MAG–Fe3O4 was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results showed that Fe3O4 nanoparticles were deposited on the interlayer and surface of magadiite. MAG–Fe3O4 was treated as an adsorbent for methylene blue (MB) removal from aqueous solutions. The adsorption properties of MAG–Fe3O4 were investigated on methylene blue; however, the results showed that the adsorption performance of MAG–Fe3O4 improved remarkably compared with MA and Fe3O4. The adsorption capacity of MAG–Fe3O4 and the removal ratio of methylene blue were 93.7 mg/g and 96.2%, respectively (at 25 °C for 60 min, pH = 7, methylene blue solution of 100 mg/L, and the adsorbent dosage 1 g/L). In this research, the adsorption experimental data were fitted and well described using a pseudo-second-order kinetic model and a Langmuir adsorption isotherm model. The research results further showed that the adsorption performance of MAG–Fe3O4 was better than that of MAG and Fe3O4. Moreover, the adsorption behavior of MB on MAG–Fe3O4 was investigated to fit well in the pseudo-second-order kinetic model with the adsorption kinetics. The authors also concluded that the isothermal adsorption was followed by the Langmuir adsorption isotherm model; however, it was found that the adsorption of the MAG–Fe3O4 nanocomposite was a monolayer adsorption.

Sign in / Sign up

Export Citation Format

Share Document