scholarly journals Investigating Methylene Blue Adsorption and Photocatalytic Activity of ZnO/CNC Nanohybrids

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Vu Nang An ◽  
Tran T. T. Van ◽  
Ha T. C. Nhan ◽  
Le Van Hieu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Concentration Ratio ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Ion Concentration ◽  
Strong Absorption Band ◽  
Pure Cellulose ◽  
Nypa Fruticans ◽  
Bet Analysis

Nanohybrids of zinc oxide/cellulose nanocrystals (ZnO/CNCs) were successfully prepared by using a low cost and green method for adsorption and photocatalytic degradation of methylene blue (MB). CNCs have been derived through the hydrolysis reaction by citric/hydrochloric acid from the pure cellulose isolated from Vietnamese Nypa fruticans trunk. The influence of the Zn2+ ion concentration on the morphology, microstructure, and thermal properties as well as the photocatalytic activity of the ZnO/CNC nanohybrids was investigated in detail. Analyses of FTIR spectra, XRD, and SEM indicated that the ZnO nanocrystals with the size of 50 nm formed and loaded on the surface of CNC. Based on the DRS spectra and the nitrogen adsorption–desorption isotherms (BET) analysis, the absorption of ultraviolet light with a strong absorption band around 400 nm was found for all the ZnO/CNC nanohybrids, and the values of specific surface areas (SBET) of materials can be controlled by changing the concentration ratio of Zn2+ ion and CNC. The TGA analysis demonstrated that the ZnO loading samples (ZnO/CNC) had the thermal degradation onset temperature higher than that of neat CNC. The effect of MB removal showed the results which were contributed not only by the adsorption ability of CNC but also by the photocatalytic activity of ZnO. The photocatalytic efficiency significantly depended on the content of ZnO loading. The maximum degradation of MB was about 95% in 150 min for the ZnO/CNC-1.0 sample in which the concentration ratio of zinc-precursor Zn(NO3)2·6H2O and CNC was 1.0.

scholarly journals Green one-step synthesis of cellulose nanocrystal/ ZnO nanohybrid with high photocatalytic activity

2021 ◽  
Vol 5 (3) ◽  
pp. first
Author(s):  
An Nang Vu ◽  
Anh Mai Tran ◽  
Nghi Tuyet Nguyen ◽  
Duyen My Ngoc Lam ◽  
Phong Pham Nam Le ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Zno Nanoparticles ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
High Photocatalytic Activity ◽  
Pure Cellulose ◽  
Nypa Fruticans ◽  
One Step ◽  
Adsorption Desorption

In this work, nanohybrid of zinc oxide/ cellulose nanocrystals (ZnO/CNC) was successfully prepared by using a low cost and green method for photocatalytic degradation of methylene blue (MB). CNC had been derived through the hydrolysis reaction by citric/hydrochloric acid from the pure cellulose isolated from Vietnamese Nypa fruticans trunk. The obtained CNC with carboxyl groups could act as a stabilizing and supporting agent to anchor ZnO nanoparticles. The chemical and crystal structures, morphology, thermal and photocatalytic properties of the ZnO/CNC nanohybrid were characterized by FESEM, FTIR, XRD, FESEM, BET, EDX, TGA, DRS and photocatalytic tests. Analyses of FTIR spectra, XRD, and FESEM indicated that the ZnO nanocrystals with the size of 50 nm formed and loaded on the surface of CNC. The TGA analysis demonstrated that the ZnO loading sample (ZnO/CNC) had the thermal degradation onset temperature higher than that of neat CNC. ZnO/CNC cuold be absorpted ultraviolet light and have high value of specific surface area (SBET), based on the DRS spectra and the nitrogen adsorption – desorption isotherms analysis, respectively. ZnO/CNC displayed more photocatalytic activity than pure ZnO upon degradation of methylene blue due to strong interaction between the CNC and ZnO nanoparticles. The maximum degradation of MB was about 95% in 150 minutes for the ZnO/CNC.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

ZnO Photocatalysts Modified with Eu2O3 and Sm2O3

2020 ◽  
Vol 850 ◽  
pp. 35-40
Author(s):  
Pāvels Rodionovs ◽  
Jānis Grabis
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Hydrothermal Method ◽  
High Photocatalytic Activity ◽  
Solar Light ◽  
Effect Of Ph ◽  
Microwave Assisted ◽  
Bet Analysis

In this study ZnO photocatalysts with different loading of Eu2O3 and Sm2O3 were prepared vie microwave-assisted hydrothermal method. The prepared samples were investigated by using XRD, SEM and BET analysis. The photocatalytic activity was determined by degradation of methylene blue (MB) under Osram Vitalux illumination. Prepared ZnO photocatalysts shown high photocatalytic activity under solar light simulated radiation. After 30 minute of irradiation more than 95 % of initial MB solution was degraded. The effect of pH and photocatalyst dosage was investigated. The reusability of photocatalysts was also studied.

scholarly journals Equilibrium and Kinetic Studies for The Adsorptive Removal of Lead (II) Ions from Aqueous Solution Using Activated Plantain Peel Biochar

2020 ◽  
Vol 4 (1) ◽  
pp. 9-16
Author(s):  
FS Nworie ◽  
EC Oroke ◽  
II Ikelle ◽  
JS Nworu
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Metal Ion ◽  
Low Cost ◽  
Kinetic Studies ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Intraparticle Diffusion Model ◽  
Activated Biochar ◽  
Bet Analysis

AbstractStudies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m2/g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies indicated the potential of plantain peel biochar as an effective, efficient and low cost adsorbent for remediating lead (II) ions contaminated environment.

Preparation of Mesoporous Magnetic TiO2/CoFe2O4 Photocatalysts Using Ionic Liquid as Template Agent

2013 ◽  
Vol 345 ◽  
pp. 201-204 ◽  
Author(s):  
Kai Wang ◽  
Lan Bo Di ◽  
Li Juan Zhang ◽  
Gui Fu Dong ◽  
Xiu Ling Zhang
Keyword(s):  
Phase Transition ◽  
Methylene Blue ◽  
Ionic Liquid ◽  
Photocatalytic Activity ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bet Analysis

A simple sol-gel method using 1-butyl-3-methylimidazoliun tetrafluoroborate ([C4MIM]BF4) ionic liquid as template agent was used to prepared mesoporous magnetic TiO2/CoFe2O4photocatalysts (denoted as IL-TiO2/CoFe2O4). The photocatalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis. The results showed that well crystallized anatase TiO2in IL-TiO2/CoFe2O4photocatalysts could be obtained when the calcination temperature was as low as 200 °C, and the phase transition temperature from anatase to rutile was increased to 800 °C. BET analysis showed that IL-TiO2/CoFe2O4was mesoporous structure. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methylene blue (MB). The results showed that photocatalytic activity of IL-TiO2/CoFe2O4was 6 times higher than that of TiO2/CoFe2O4when a low calcination temperature of 350 °C was used.

scholarly journals Carbon-containing Hydroxyapatite Obtained from Fish Bone as Low-cost Mesoporous Material for Methylene Blue Adsorption

2019 ◽  
Vol 14 (3) ◽  
pp. 660 ◽  
Author(s):  
Mukhamad Nurhadi ◽  
Ratna Kusumawardani ◽  
Wirhanuddin Wirhanuddin ◽  
Rahmat Gunawan ◽  
Hadi Nur
Keyword(s):  
Methylene Blue ◽  
Surface Area ◽  
Low Cost ◽  
Industrial Effluents ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Fish Bone ◽  
Hydroxyapatite Nanoparticles ◽  
Adsorption Model ◽  
East Kalimantan

The carbon-containing hydroxyapatite has been synthesized using the fish bone obtained from East Kalimantan, Indonesia. The synthesis was conducted at varying calcination temperature (300-700 °C) and duration time (1-5 h). The carbon-containing hydroxyapatite were characterized by using Nitrogen adsorption-desorption, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Thermogravimetric analysis (TGA) and Differential thermal analysis (DTA). The carbon-containing hydroxyapatite nanoparticles consisted of the mesoporous structure with a specific surface area of 159 m2.g-1 and pore size of 44 Å. The carbon-containing hydroxyapatite nanoparticles were utilized as the adsorbent for the removal of methylene blue by varying the contact time, initial dye concentration, pH, adsorbent dosage and temperature. The maximum amount of adsorption capacity was 56.49 mg.g-1. The adsorption was well fitted with the Langmuir adsorption model (R2 ~ 0.998) and the pseudo-second-order model. This indicated that the dye molecules were adsorbed on the surface-active site of carbon-containing hydroxyapatite via chemical binding, forming an adsorbate monolayer. Hence, the adsorption capability corresponds to the physical properties such as the surface area and pore volume of hydroxyapatite because the larger surface area consists of higher binding sites for the adsorption. Thermodynamic parameters, including the Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS), indicated that the adsorption of methylene blue onto the carbon-containing hydroxyapatite nanoparticles was spontaneous. Thus, carbon-containing hydroxyapatite nanoparticles can be applied as a low-cost adsorbent for the treatment of industrial effluents that are contaminated with the methylene blue. Copyright © 2019 BCREC Group. All rights reserved 

scholarly journals Synthesis of Ag-TiO2/perlite composite for the photodegradation of methylene blue under solar light irradiation

2020 ◽  
Vol 9 (4) ◽  
pp. 42-48
Author(s):  
Nui Pham Xuan ◽  
Hoa Nguyen Thi ◽  
Tien Nguyen Trung ◽  
Tai Le Huu ◽  
Thi Tran Thi Van
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation ◽  
Adsorption Desorption

In this research, photocatalytic materials of TiO2, Ag-TiO2, Ag-TiO2/perlite were synthesized by the sol-gel method. By combining the photocatalytic activity between Ag-TiO2 and Perlite mineral, the Ag-TiO2/perlite composite has overcome the disadvantages of pristine TiO2, such as high band gap energy, low light utilization and easy recombination of electrons and holes. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm, UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of the samples was tested for degradation of methylene blue (MB) under solar light irradiation. Photodegradation studies revealed a 95% removal of MB dye via the synthesized Ag-TiO2/perlite after 150 min of irradiation. Reusability of this hybrid photocatalyst system was tested and only a 3% decrease was observed after four cycles.

Mechanical-assisted preparation and photocatalytic properties of almost-visible light-driven ZnO/ZnFe2O4 nanocomposites

2014 ◽  
Vol 1641 ◽  
Author(s):  
Jiaqian Qin ◽  
Yanan Xue ◽  
Xinyu Zhang ◽  
Riping Liu
Keyword(s):  
Thermal Decomposition ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Aqueous Medium ◽  
Decomposition Method ◽  
Low Cost ◽  
Thermal Decomposition Method ◽  
Visible Light Driven ◽  
Shape And Size

ABSTRACTZnO and ZnO/ZnFe2O4 nanocomposites were synthesized by mechanical-assisted thermal decomposition method. The results show that this method is a simple and low cost method to prepare ZnO and ZnO/ ZnFe2O4 nanocomposites. The nanorod's shape and size have been identified through SEM and TEM. The photocatalytic activity of ZnO and ZnO/ZnFe2O4 nanocomposites were tested by the degradation of methylene blue (MB) in aqueous medium under almost-visible light and the efficiency of the catalyst has been discussed in detail.

scholarly journals TiO2 NANOTUBES FOR PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Vladimir Ciobanu ◽  
◽  
Irina Plesco ◽  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Low Cost ◽  
Anatase Phase ◽  
Electrochemical Anodization ◽  
Outer Diameter ◽  
Light Illumination ◽  
Vis Spectroscopy

Titanium dioxide remains one of the most studied semiconductor for photocatalytic applications due to its low cost production, reduced toxicity, ability to break down the organic pollutants and possibility to achieve complete mineralization. In this work, we report on results of the photocatalytic activity of titanium dioxide nanotubes fabricated by electrochemical anodization technique in an electrolyte solution containing a mixture of hydrofluoric acid, ethylene glycol and phosphoric acid. The morphology and crystallinity of the obtained nanotubes were investigated by means of electron microscopy and it was found that nanotubes have a constant outer diameter of 200 nm and an internal conical shape where the diameter gradually decreases from 120 nm at the wide end to 50 nm at the narrow end. The transmission electron microscopy investigation defined two different phases of titanium dioxide obtained after annealing of amorphous TiO2 in air at 650 °C and 850 °C. Photocatalytic activity of the samples have been evaluated in methylene blue solution in the presence of dispersed nanotubes under visible and UV irradiation by means of UV/Vis spectroscopy. Anatase phase TiO2 shows the best performance degrading 85 % of dye in 25 min under UV illumination, while rutile phase with anatase inclusions shows the best results with a 50 % decay of dye concentration in 25 min under visible light illumination.

scholarly journals In-Situ Fabrication of g-C3N4/ZnO Nanocomposites for Photocatalytic Degradation of Methylene Blue: Synthesis Procedure Does Matter

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 215 ◽  
Author(s):  
Shengqiang Zhang ◽  
Changsheng Su ◽  
Hang Ren ◽  
Mengli Li ◽  
Longfeng Zhu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Zinc Acetate ◽  
Diffuse Reflectance Spectroscopy ◽  
Low Cost ◽  
Zno Nanorods ◽  
Light Illumination ◽  
Maximum Reaction Rate ◽  
In Situ Fabrication

The nanocomposite preparation procedure plays an important role in achieving a well-established heterostructured junction, and hence, an optimized photocatalytic activity. In this study, a series of g-C3N4/ZnO nanocomposites were prepared through two distinct procedures of a low-cost, environmentally-friendly, in-situ fabrication process, with urea and zinc acetate being the only precursor materials. The physicochemical properties of synthesized g-C3N4/ZnO composites were mainly characterized by XRD, UV–VIS diffuse reflectance spectroscopy (DRS), N2 adsorption-desorption, FTIR, TEM, and SEM. These nanocomposites’ photocatalytic properties were evaluated in methylene blue (MB) dye photodecomposition under UV and sunlight irradiation. Interestingly, compared with ZnO nanorods, g-C3N4/ZnO nanocomposites (x:1, obtained from urea and ZnO nanorods) exhibited weak photocatalytic activity likely due to a “shading effect”, while nanocomposites (x:1 CN, made from g-C3N4 and zinc acetate) showed enhanced photocatalytic activity that can be ascribed to the effective establishment of heterojunctions. A kinetics study showed that a maximum reaction rate constant of 0.1862 min-1 can be achieved under solar light illumination, which is three times higher than that of bare ZnO nanorods. The photocatalytic mechanism was revealed by determining reactive species through adding a series of scavengers. It suggested that reactive ∙O2− and h+ radicals played a major role in promoting dye photodegradation.

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