scholarly journals Synthesis and Characterization of Zinc Peroxide Nanoparticles for the Photodegradation of Nitrobenzene Assisted by UV-Light

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1041
Author(s):  
Jesús Isaías De León Ramírez ◽  
Víctor Alfredo Reyes Villegas ◽  
Sergio Pérez Sicairos ◽  
Esteban Hernández Guevara ◽  
Mirna Del Carmen Brito Perea ◽  
...  

The contamination of both soil and water by nitrobenzene (NB) is a problem that has been studied, where several reactive agents have been developed for the degradation of this compound as well as different methods. Nanoparticles with semiconductive properties have been studied for organic compounds photodegradation due to their assistance in optimizing the degradation processes. Two of the most promising photocatalysts are ZnO and TiO2 because of their optimal results. In the present work the performance of the zinc peroxide (ZnO2) nanoparticles was evaluated. ZnO2 nanoparticles were synthesized from zinc acetate and hydrogen peroxide using the Sol-Gel method under ultrasound assistance. The characterization was carried out by UV–Vis spectroscopy, infrared Fourier transform total reflectance (ATR-FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), Zeta potential, dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), and Energy Dispersive X-ray spectroscopy (EDX). The experiments for the degradation of NB were carried out in a photoreactor with UV lamps of 254 nm at 25 °C, using a solution of nitrobenzene with the nanoparticles. The best conditions for NB photodegradation were 30 ppm (ZnO2) and 15 ppm (NB) at pH 2, reaching up to 90% degradation in 2 h. The intermediates formed during the photodegradation of NB were identified by gas chromatography mass spectrometry.

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1498 ◽  
Author(s):  
Abdul Hafeez ◽  
Zareen Akhter ◽  
John F. Gallagher ◽  
Nawazish Ali Khan ◽  
Asghari Gul ◽  
...  

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.


2019 ◽  
Vol 37 (3) ◽  
pp. 304-309
Author(s):  
Azeezaa Varsha Mohammed ◽  
Suresh Sagadevan

AbstractL-cysteine hydrogen fluoride (LCHF) single crystals were grown from aqueous solution. Single crystal X-ray diffraction, FT-IR, UV-Vis-NIR, and TG-DTA were used to test the grown crystals. The specimen dielectric and mechanical behaviors were also studied. Powder X-ray diffraction of the grown crystal was recorded and indexed. The optical properties of the LCHF crystal were determined using UV-Vis spectroscopy. It was found that the optical band gap of LCHF was 4.8 eV. The crystal functional groups were identified using FT-IR. Second harmonic generation (SHG) efficiency of the LCHF was three times higher than that of KDP. The dielectric constant, dielectric loss and AC conductivity were measured at different frequencies and temperatures.


2015 ◽  
Vol 1087 ◽  
pp. 218-222
Author(s):  
Siti Aida Ibrahim ◽  
Srimala Sreekantan

Nanostructured Fe-TiO2 and TiO2 with anatase structure were synthesized via combination method of sol-gel and peptization process. The samples were characterized by X-ray diffraction (XRD), Transmission emission microscopy (TEM) and UV-Vis spectroscopy (UV-Vis). The presence of Fe3+ ion shifted the absorption profile of TiO2 to the longer wavelength side of the spectrum, indicating an obvious photocatalytic activity under visible irradiation. Photocatalytic activity of the samples were evaluated by methyl orange (MO) discolouration under UV-light irradiation. Compared with the pure TiO2 nanoparticles, the Fe-TiO2 nanoparticles exhibited higher photocatalytic activity with 95% discoloration within 2 h.


2011 ◽  
Vol 233-235 ◽  
pp. 1188-1191
Author(s):  
Hong Cai ◽  
Yan Chen ◽  
Yun Ying Wu

Nano-TiO2 particles were prepared by sol-gel method, of which the surfaces were coated by SiO2. The coating was achieved by the hydrolysis of sodium silicate (Na2SiO3) in ammonium chloride (NH4Cl). The surface bonding, phase constitution and chemical components of the samples were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy (XPS). The mechanism of the SiO2 coating process onto TiO2 surface was analyzed. Results show that SiO2 particles were immobilized on the TiO2 surface via Ti—O—Si bondings, which formed at the interface. The SiO2 layer on TiO2 surface was amorphous, the photocatalytic performance was decreased of the TiO2 while its stability was enhanced after surface modification.


2021 ◽  
Author(s):  
Faiza Lughmani ◽  
Farzana Nazir ◽  
Shahid Ali Khan ◽  
Mudassir Iqbal

Abstract In this study, microcrystalline cellulose (MCC) was modified to oxidized cellulose (OC), 6-deoxycellulose hydrazide and 6-deoxycellulose(N,N-diethyl)amine (MCC-Hyd and MCC-DEM) derivatives and employed as supporting material for the synthesis of copper nanoparticles (NPs). Copper ions from aqueous solution were adsorbed and then reduced to zero valent copper (ZVC) NPs using sodium borohydride on films of prepared derivatives. The characterization of prepared derivatives and Cu NPs embedded films was performed using Fourier Transform Infrared Spectroscopy (FT-IR), Elemental analysis, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Nuclear Magnetic Resonance (NMR) spectroscopy. Ultraviolet/Visible (UV-VIS) spectroscopy was performed for the degradation studies of 4-nitrophenol (4-NP) and various azo dyes viz. Congo Red (CR), Methylene Blue (MB), and Methyl orange (MO). Results revealed that all the films showed degradation only in the presence of ZVC NPs. Oxidized cellulose, MCC-Hyd and MCC-DEM showed excellent degradation efficiencies (> 85%) in all the cases. Our findings revealed that MCC derivatives could be efficient and renewable candidates for removal of water pollutants in future.


2017 ◽  
Vol 748 ◽  
pp. 413-417
Author(s):  
Chun Yu Long ◽  
Fang Fang Peng ◽  
Min Min Jin ◽  
Pei Song Tang ◽  
Hai Feng Chen

Using Pr (NO3)3, butyl titanate, ethylene glycol and citric acid as main raw materials, praseodymium titanate (Pr2Ti2O7) was prepared by the sol-gel process. The samples were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), thermal gravity-differential thermal analysis (TG-DTA), diffuse-reflection spectra (DRS) and Fourier transform infrared (FT-IR). The effect of different calcination temperature and illumination time on the photocatalytic properties of Pr2Ti2O7 was investigated. It was found that the single phase Pr2Ti2O7 could be obtained through sol-gel process and calcination at 1000 °C. The Pr2Ti2O7 samples calcination at 1000 °C were uniform , and the resulting product had a particle size of 200 nm and an optical band gap of 3.26 eV. Under ultraviolet light, the degradation of methyl orange arrived to 80.11% after 180 min of photocatalytic reaction. The Pr2Ti2O7 samples showed good photocatalytic activity for decomposition of methyl orange.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
D. K. Calvo Ramos ◽  
M. Vega González ◽  
R. A. Esparza Muñóz ◽  
J. Santos Cruz ◽  
F. J. De Moure-Flores ◽  
...  

Titanium dioxide (TD) and graphene oxide (GO) were synthesized by sol-gel and improved Hummers method, respectively. This study shows the results of the incorporation through four different conditions (sol-gel, sol-gel and ultrasonic, annealed, and UV radiation, C1 to C4, respectively). It was observed that a homogeneous incorporation of TD on sheets of GO was obtained satisfactorily. The composites of TiO2/GO were characterized using different techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, and infrared spectroscopy (IR). The photocatalytic activity of the composites was determined from the degradation of the dye azo tartrazine using UV and solar radiation. The best incorporation of TD nanoparticles on GO was obtained with condition C3 (thermal incorporation method) at a temperature of 65°C. This shows a uniformity in the size and shape of the TD as well as an excellent adherence to the sheet of GO. This addition is accomplished by ionic bonding in the presence of electrostatic Coulomb forces. The C3 composite degraded the tartrazine dye using UV radiation and sunlight. With the latter, the degradation time was three times faster than using UV light.


2021 ◽  
Author(s):  
Wanzhen Zhong ◽  
Weizhang Fu ◽  
Shujuan Sun ◽  
Lingsheng Wang ◽  
Huaihao Liu ◽  
...  

Abstract Excessive N-NO3- water pollution has become a widespread and serious problem that threatens human and ecosystem health. Here, a TiO2/SiO2 composite photocatalyst was prepared via the sol-gel/hydrothermal method. TiO2 and TiO2/SiO2 were characterized by X-ray diffraction (XRD), UV-Vis differential reflectance spectroscopy (DRS), Fourier infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Afterward, the photocatalytic performance of TiO2 and TiO2/SiO2 to reduce low nitrate concentrations (30 mgN·L-1) under UV light were evaluated and the effects of different factors on this process were investigated, after which the reaction conditions were optimized. Removal rates of up to 99.93% were achieved at a hole scavenger (formic acid) concentration of 0.6 mL·L-1, a CO2 flow rate of 0.1 m3·h-1, and a TiO2 concentration of 0.9 g·L-1. In contrast, TiO2/SiO2 at a 1.4 g·L-1 concentration and a TiO2 load rate of 40% achieved a removal rate of 83.48%,But with more than 98% of nitrogen generation rate.NO2- and NH4+ were the minor products, whereas N2 was the main product.


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Rika Rahayu ◽  
◽  
Posman Manurung ◽  
Yanti Yulianti ◽  
◽  
...  

Titanium dioxide has been prepared through the sol gel method using the addition of ethanolamine. The research was conducted to study the effect of MEA on the formation of TiO2. The amount of MEA was varied to 0; 0.5; 1; 1.5; and 2 ml respectively. The samples were calcined at a temperature of 500 ºC. TiO2was characterized using X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and photocatalyst tests using UV lamps. The XRD characterization results showed that in the A sample an anatase phase was formed whereas in the Csample an anatase phase and a brookite phase were formed. The resultof TEM characterization using ImageJ software show that the particle size of TiO2 is26,1 nm, respectively. The results of the characterization of the fastest photocatalyst catalyst test occurred in sample C which the variation of MEA is 1 ml.


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