scholarly journals Characterization of Tio2 And An As-Prepared Tio2/Sio2 Composite And Their Photocatalytic Performance For The Reduction Of Low-Concentration N-NO3- In Water

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.

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.


2014 ◽  
Vol 609-610 ◽  
pp. 250-254
Author(s):  
Ya Bin Li ◽  
Jin Tian Huang ◽  
Yan Fei Pan

In the paper, the TiO2nanomaterials adopted the microcrystalline cellulose as the template by the template method and sol-gel method was prepared. Through the infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), the surface morphology, composition and the type of the samples were characterized respectively. The influence of the macro morphology of TiO2photocatalytic performance to use the reaction of decolorization and degradation of methyl orange as model was analyzed. The results showed that TiO2which was produced by the template of sallix fiber was Rod-shaped and the average diameter size of nanocomposite structure was 20.592 nm, which can provide a new method of producing other morphology of TiO2.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1671 ◽  
Author(s):  
Weike Zhang ◽  
Yanrong Zhang ◽  
Kai Yang ◽  
Yanqing Yang ◽  
Jia Jia ◽  
...  

A silicon dioxide/carbon nano onions/titanium dioxide (SiO2/CNOs/TiO2) composite was synthesized by a simple sol-gel method and characterized by the methods of X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analysis (TG), differential scanning calorimeter (DSC) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). In this work, the photocatalytic activity of the SiO2/CNOs/TiO2 photocatalyst was assessed by testing the degradation rate of Rhodamine B (RhB) under visible light. The results indicated that the samples exhibited the best photocatalytic activity when the composite consisted of 3% CNOs and the optimum dosage of SiO2/CNOs/TiO2(3%) was 1.5 g/L as evidenced by the highest RhB degradation rate (96%). The SiO2/CNOs/TiO2 composite greatly improved the quantum efficiency of TiO2. This work provides a new option for the modification of subsequent nanocomposite oxide nanoparticles.


2010 ◽  
Vol 663-665 ◽  
pp. 187-190 ◽  
Author(s):  
Yu Hui Zhang ◽  
Ji Xin Su ◽  
Xiao Peng Wang ◽  
Qi Pan ◽  
Wen Qu

Based on X-ray diffraction results, the gallery height of modified Mg3Al-LDH was expanded to 9.6Å from the original 4.8Å, indicating that the H3PW12O40 was indeed inserted into the hydroxide layers. Moreover, the results of FT-IR spectra proved the Keggin structure of PW11O397- species. The resulting material showed a high activity of degradation of methyl orange in the presence of H2O2 and UV light irradiation.


2017 ◽  
Vol 17 (6) ◽  
pp. 1730-1739 ◽  
Author(s):  
Guangpeng Li ◽  
Hui Jiang ◽  
Dan Li ◽  
Tianyu Liao ◽  
Lingling Yuan ◽  
...  

Abstract To remove As(III) in water, the composite material of TiO2@ZIF-8 was prepared by a sol-gel method with zeolitic imidazolate framework-8 (ZIF-8) as the matrix. The structure of TiO2@ZIF-8 was characterized with scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The results indicated that the best loading efficiency of TiO2 on ZIF-8 occurred when it was calcined at 300 °C for 3 h. This material was used to remove As(III) from aqueous solution, and the effect of the initial concentration of As(III), pH, and the illumination condition on the removal of As(III) was investigated. The results showed that the removal rate of As(III) was as high as 100% under a pH of 4–7, an initial As(III) concentration of less than 2 mg/L, and UV-light irradiation for 2 h. The repeated experiments were also performed for the investigation of the stability of TiO2@ZIF-8.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012089
Author(s):  
B Usharani ◽  
V Manivannan ◽  
P Shanmugasundaram

Abstract Picric acid is a very dangerous environmental pollutant generated from chemical and dye industries due to its high toxicity. Therefore, efforts have been made to develop techniques for the efficient degradation of picric acid. A novel rGO-MnO2 nanocomposite has been synthesized by chemical method for the degradation of picric acid in various light medium. The rGO-MnO2 nanocomposite was characterized by X-ray Photoelectron Spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Energy dispersive X-ray (EDAX), Ultraviolet-visible (UV-Vis) and Scanning electron microscope (SEM). The synthesized, pure rGO, MnO2 and rGO-MnO2 nanocomposite catalyst have been studied for the activity of photocatalytic degradation against picric acid under different light sources such as UV light (254,365,390 nm), visible light and sunlight. It is found that rGO-MnO2 has achieved better performance compared to that of pure rGO, MnO2.


Author(s):  
Julie Joseane Murcia Mesa ◽  
Ceidy Geraldine Patiño Castillo ◽  
Hugo Alfonso Rojas Sarmiento ◽  
José Antonio Navío Santos ◽  
María del Carmen Hidalgo López ◽  
...  

The aim of the present work was to evaluate the effectiveness of a heterogeneous photocatalyst based on TiO2 in the treatment of coal mining drainage which contains a variety of heavy metals and high concentration sulfates and sulfides. The photocatalytic behavior of the commercial reference Sigma Aldrich and the different materials synthesized using the Sol-gel methodology with surface modifications using sulfation and fluorination processes were analyzed. To find a possible correlation between the physicochemical properties of photocatalysts and their behavior, a characterization was carried out using X-Ray Diffraction (XRD), X-Ray Fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FT–IR), UV–Vis diffuse reflectance Spectra (UV-Vis DRS), N2 physisorption, X-ray photoelectron spectroscopy (XPS), and particle size analysis. Results indicated that the modification of the TiO₂ prepared in the laboratory using sulfation and fluorination allowed the successful control of the physicochemical properties of this oxide. However, commercial TiO2 showed the greatest effectiveness in removing metals such as: Fe, Cu, Cr, and As after a photocatalytic reaction for a maximum of 1 hour under continuous nitrogen flow and a light intensity of 120 W/m2.


2017 ◽  
Vol 10 (06) ◽  
pp. 1750072 ◽  
Author(s):  
Junshu Wu ◽  
Linlin Wang ◽  
Jinshu Wang ◽  
Yucheng Du ◽  
Yongli Li

This paper reports the synthesis of MgO-based nanosheets loaded with UV-light absorbed, wurtzite ZnxMg[Formula: see text]O nanoparticles based on calcining Zn[Formula: see text]-adsorbed Mg(OH)2 precursor, as evidenced by X-ray diffraction, UV-visible, X-ray photoelectron spectroscopy analyses, etc. The surface modification of magnesium oxide (MgO) sheet-like adsorbents by Zn–Mg–O alloys generates photocatalytic activity for the degradation removal of cationic dye Rhodamine B and anionic dye methyl orange under UV light irradiation. These findings provide a route to chemically controlled synthesis of new and highly robust MgO–ZnxMg[Formula: see text]O materials for water purification. The endowed photocatalysis function of MgO makes it be easily recovered via photodegradation of adsorbed dyes rather than high-temperature calcination, thus extending the applications of MgO in dye wastewater treatment.


2010 ◽  
Vol 132 ◽  
pp. 105-110 ◽  
Author(s):  
Kun Wan ◽  
Xiang Hong Peng ◽  
Ping Jing Du

Chitin/TiO2 composite was prepared through colloid TiO2 deposited on the chitin by controlling the pH value of the system, while colloid TiO2 was synthesized by the sol–gel method using tetrabutyl titanate as a precursor. The structures and morphologies of the chitin/TiO2 composite were characterized by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic degradation of phenol was investigated by HPLC method. The results revealed that the chitin/ TiO2 composite was an efficient photocatalyst for the degradation of phenol, and 99.2% of the phenol was degraded after 6h under UV light. The TiO2 was adsorbed on the chitin by hydrogen and titanoxane bonds between them. Colloid TiO2 was gradually deposited to form the anatase crystallographic structures, showing 2θ = 25.3, 37.8, 47.8 and 54.6. Such biocompatible photocatalyst might be applied in the field of various phenol pollutants abatement.


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.


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