Green Synthesis of NiO Nanoparticle Using Ziziphus Spina-Christi Leaves Extract for Photocatalytic Methylene Blue Dye Degradation

2021 ◽  
Vol 13 (9) ◽  
pp. 1756-1763
Author(s):  
Hamdah S. Alanazi ◽  
Hanan Alotaibi ◽  
Hamza S. Al-Shehri ◽  
Fahad A. Alharthi

In this presented work, ziziphus spina-christi leaves extract assisted green synthesise approach was used to prepare the NiO nanoparticle for UV light driven photocatalytic methylene blue (MB) dye degradation. Various analytical characterizations were used to understand the crystalline, structural, optical and morphological nature of the prepared nanoparticle. The prepared NiO nanoparticle have wide bandgap of 3.35 eV with average particle size of around 10–15 nm in range. Various environmental conditions and elemental trapping experiments were conducted to understand the factors affecting the MB degradation and main active species for the redox reaction. Hence, we hope that this green synthesise NiO would pave a new way for photocatalytic preparation and their environmental remediation application.

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2360
Author(s):  
Seyedehmaryam Moosavi ◽  
Rita Yi Man Li ◽  
Chin Wei Lai ◽  
Yusliza Yusof ◽  
Sinyee Gan ◽  
...  

In this study, activated carbon (AC) from coconut shell, as a widely available agricultural waste, was synthesised in a simple one-step procedure and used to produce a magnetic Fe3O4/AC/TiO2 nano-catalyst for the degradation of methylene blue (MB) dye under UV light. Scanning electron microscopy revealed that TiO2 nanoparticles, with an average particle size of 45 to 62 nm, covered the surface of the AC porous structure without a reunion of its structure, which according to the TGA results enhanced the stability of the photocatalyst at high temperatures. The photocatalytic activities of synthesised AC, commercial TiO2, Fe3O4/AC, and Fe3O4/AC/TiO2 were compared, with Fe3O4/AC/TiO2 (1:2) exhibiting the highest catalytic activity (98%). Furthermore, evaluation of the recovery and reusability of the photocatalysts after treatment revealed that seven treatment cycles were possible without a significant reduction in the removal efficiency.


2018 ◽  
Vol 18 (44) ◽  
pp. 5-11 ◽  
Author(s):  
Nizamettin Demirkıran ◽  
G D Turhan Özdemir ◽  
M Saraç ◽  
M Dardağan

In this study, the adsorption of methylene blue dye was examined by using pyrolusite ore as a low-cost alternative adsorbent source. Pyrolusite, which contains mainly MnO2, is a manganese ore. The effects of the initial concentration of dye, contact time, initial pH of solution, adsorbent dosage, stirring speed of solution, and average particle size of adsorbent on the adsorption of methylene blue were studied. It was found that the percentage of the adsorbed dye increased with increasing the amount of pyrolusite. While the initial dye concentration, initial pH, contact time, stirring speed, particle size, and adsorbent dosage were 25 ppm, 6, 90 min, 250 rpm, 63 µm, and 12 g/l, respectively, the efficiency of dye adsorption on pyrolusite ore was 99%. The isotherm and kinetic studies relating to this adsorption process were also made. It was found that the equilibrium data followed the Langmuir isotherm model while the kinetic of process could be described by the pseudo-second order kinetic model.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2439 ◽  
Author(s):  
Maria Antoniadou ◽  
Michalis K. Arfanis ◽  
Islam Ibrahim ◽  
Polycarpos Falaras

A bifunctional thin film photocatalyst consisting of graphitic carbon nitride on tungsten trioxide (g-C3N4/WO3) is introduced for the improvement of photocatalytic activity concerning hexavalent chromium reduction and methylene blue dye removal in water, compared to the bare, widely used WO3 semiconductor. A bilayered structure was formed, which is important for the enhancement of the charge carriers’ separation. The characterization of morphological, structural, optoelectronic, and vibrational properties of the photocatalysts permitted a better understanding of their photocatalytic activity for both dye degradation and Cr+6 elimination in water and the analysis of the photocatalytic kinetics permitted the determination of the corresponding pseudo-first-order reaction constants (k). Trapping experiments performed under UV illumination revealed that the main active species for the photocatalytic reduction of Cr+6 ions are electrons, whereas in the case of methylene blue azo-dye (MB) oxidation, the activation of the corresponding photocatalytic degradation comes via both holes and superoxide radicals.


2021 ◽  
Author(s):  
NORAIN ISA ◽  
Mohamed Syazwan Osman ◽  
Haslinda Abdul Hamid ◽  
Nurdiana Samsulrizal ◽  
Vicinisvarri Inderan ◽  
...  

Abstract The textile industry is a heavy producer of wastewater, which may result in the discharge of toxic dyes into the environment. Methylene blue (MB) is an example of the most used dye in the textile industry. It is difficult to degrade MB under normal conditions due to its highly stable molecules. Therefore, a catalyst route is desired in MB reduction. The catalyst chosen in this work was silver nanoparticles (AgNPs) synthesised by a biological method utilising shortleaf spikesedge extract (SSE) as a reducing agent. The formations of SSE driven AgNPs were monitored using visual observation (colour), ultraviolet-visible spectroscopy (UV-vis), and transmission electron microscopy (TEM). The different process variables (concentration of AgNO3, concentration of SSE, reaction time, temperature and pH) upon synthesis of SSE driven AgNPs were evaluated based on the absorbance of surface plasmon resonance (SPR) band. The TEM image showed that SSE driven AgNPs are highly dispersed with a quasi-spherical shape and an average particle size of approximately 17.64 nm. For the catalytic study, the reduction of MB was evaluated using two systems. A detailed batch study of the removal efficiency (%RE) and kinetics was done at ambient temperature, various MB initial concentrations, and reaction time. The batch study for System 2 clearly showed that SSE driven AgNPs exhibited 100% reduction of MB at 30–100 mg/L initial concentration (sample coding of MB30, MB50, MB70 and MB100) between 1.5 and 5.0 min reaction time. The kinetic data best fitted a pseudo-first-order kinetic model with the highest reaction rate of 2.5715 min-1. The reduction of MB occurs via the electron relay effect. These findings demonstrate that the SSE driven AgNPs are a promising candidate with potential influence on coloured wastewater.


2021 ◽  
Author(s):  
Wisam Aziz ◽  
Muslim Abid ◽  
Aya Jumaa

Abstract In this study, iron oxide nanoparticles were synthesized using FeCl3 (0.1 M and 0.3 M) with myrtle leaf extract for of methylene blue dye (MBD) degradation under visible light irradiation (100-watt halogen lamp) as environmental application. X-ray diffraction analysis showed the polycrystalline structure of Fe2O3 material with miller indices confirmed the presence of iron oxide with average crystalline sizes (15.59-16.8 nm) synthesized by (0.1M - 0.3mM) concentrations of FeCl3. Field emission-scanning electron microscopy revealed rods-like and spherical shapes of Fe2O3 nanoparticles, with an average particle size of 25 to 67 nm, covered the whole top surface of structure. Moreover, the change of the color of the iron oxide NPs from brown to dark brown enhances the transformation of the properties of the material obtained by adding the biomass which gives the absorbance peaks around 265-350 nm and energy band gaps (3 and 3.7 eV) using UV/VIS spectrometer. The methylene blue degradation efficiencies of Fe2O3 NPs prepared by plant extract and FeCl3 with concentrations (0.1 M and 0.3 mM) were 86.3% after 150 min and 90% after 120 min respectively.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
H. Yang ◽  
T. Xian ◽  
L. J. Di ◽  
R. S. Li ◽  
...  

Spherical Bi2WO6nanoparticles were synthesized by a hydrothermal route. SEM observation shows that the size of the particles ranges from 60 to 120 nm and the average particle size is ~85 nm. TEM investigation shows that the particles are made up of subgrains with size of 5–10 nm. The bandgap energy of the particles is measured to be 2.93 eV by ultraviolet-visible diffuse reflectance spectroscopy. RhB was chosen as the target pollutant to evaluate the photocatalytic activity of the particles under irradiation of simulated sunlight, revealing that they exhibit an obvious photocatalytic activity. The effects of ethanol, KI, and BQ on the photocatalytic efficiency of Bi2WO6particles towards the RhB degradation were investigated. It is observed that ethanol has no effect on the photocatalytic degradation of RhB, whereas KI and BQ exhibit a substantial suppression of RhB degradation. No hydroxyl (•OH) is found, by the photoluminescence technique using terephthalic acid as a probe molecule, to be produced over the irradiated Bi2WO6particles. Based on the experimental results, photoexcited hole (h+) and superoxide (•O2-) are suggested to be the two main active species responsible for the dye degradation, while •OH plays a negligible role in the photocatalysis.


2020 ◽  
Vol 4 (3) ◽  
pp. 148-153
Author(s):  
Moses Titus Yilleng ◽  
Moses Sunday ◽  
Doctor Stephen

Titanium dioxide has proven to be one of the most promising heterogeneous catalyst. This work explores the photocatalytic activity of modified titanium dioxide. Nitrogen was incorporated into mesoporous TiO2 using Sol-gel method. The N-TiO2 was characterized using X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) thermogravimetric analysis (TGA), and U-Vis diffuse reflectance spectroscopy (DRS). 1%wtN-TiO2 expresses the highest photoactivity in UV light compared to 3%wtN-TiO2 and 5%wt N-TiO2 respectively. The photodegradation efficiency of the catalyst follows the following trend 1%wtN-TiO2 >3%wtN-TiO2 >5%wtN-TiO2>PURE-TiO2. The results obtained from the kinetics investigation shows the following trends 1%wtN-TiO2 is 0.049 s-1, 3%wtN-TiO2 is 0.0289 s-1, 5%wtN-TiO2 is 0.0143 s-1, and the PURE-TiO2 is 0.0118 s-1. The consistency in the rate constant values of the phodegradation of methylene blue; it clearly showed that the reaction follows a pseudo-first order kinetics.


2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Tajamal Hussain ◽  
Mira Tul Zubaida Butt ◽  
Mirza Nadeem Ahmed ◽  
Muhammad Hamid Raza ◽  
Zahoor Hussain Farooqi ◽  
...  

Metal nanoparticles (NPs) have received significant attention in last decade because of their unique properties. In this work, two different metal NPs have been prepared and their catalytic activities are compared with conventional catalyst. In first case, Ag NPs were synthesized by chemical reduction method in ethanolic medium. Synthesized Ag NPs were characterized by scanning electron microscope (SEM) images which indicated an average particle size of Ag around 250 nm. The catalytic activity of Ag NPs was investigated for the oxidative mineralization of methylene blue dye. Comparative studies suggested that Ag NPs possess enhanced catalytic activity compared to bulk Ag. In second approach, supported Ni NPs were fabricated using Al2O3as supporting surface; that is, Ni NPs get adsorbed on Al2O3through in situ reduction reaction. Oxidative degradation of methylene blue indicated that catalytic activity of supported Ni/Al2O3is about five times higher than simple Ni as catalyst.


2019 ◽  
Vol 74 (3) ◽  
pp. 259-263 ◽  
Author(s):  
M. Shamshi Hassan

AbstractHierarchical bismuth vanadate (BiVO4) nano-knitted hollow cages have been synthesized by simple hydrothermal method and characterized by scanning electron microscopy, x-ray diffraction, energy-dispersive x-ray spectrometer, Fourier transform infrared, UV-Vis, and Raman. The photodegradation efficiency of BiVO4 nanocage for universally used methylene blue dye. The BiVO4 hollow nanostructure demonstrated better photocatalytic competence in dye degradation as compared to the commercial TiO2 powders (P25). The excellent dye degradation can be certified to the high crystallisation of monoclinic BiVO4 and hollow nanostructure, which leads to high surface area and small bandgap energy of 2.44 eV.


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