scholarly journals Preparation of TiO2@ZIF-8 for the removal of As(III) in water

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 ◽  
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.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Baolin Xing ◽  
Changliang Shi ◽  
Chuanxiang Zhang ◽  
Guiyun Yi ◽  
Lunjian Chen ◽  
...  

Photocatalysts comprising nanosized TiO2particles on activated carbon (AC) were prepared by a sol-gel method. The TiO2/AC composites were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, nitrogen adsorption, scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X-ray (EDX). Their photocatalytic activities were studied through the degradation of Rhodamine B (RhB) in photocatalytic reactor at room temperature under ultraviolet (UV) light irradiation and the effect of loading cycles of TiO2on the structural properties and photocatalytic activity of TiO2/AC composites was also investigated. The results indicate that the anatase TiO2particles with a crystal size of 10–20 nm can be deposited homogeneously on the AC surface under calcination at 500°C. The loading cycle plays an important role in controlling the loading amount of TiO2and morphological structure and photocatalytic activity of TiO2/AC composites. The porosity parameters of these composite photocatalysts such as specific surface area and total pore volume decrease whereas the loading amount of TiO2increases. The TiO2/AC composite synthesized at 2 loading cycles exhibits a high photocatalytic activity in terms of the loading amount of TiO2and as high as 93.2% removal rate for RhB from the 400 mL solution at initial concentration of 2 × 10−5 mol/L under UV light irradiation.


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 (2) ◽  
pp. 264 ◽  
Author(s):  
Muflikhah Muflikhah ◽  
Bambang Rusdiarso ◽  
Edy Giri Rachman Putra ◽  
Nuryono Nuryono

Modification of silica coated on magnetic material iron sand with chitosan for adsorption of Au(III) has been carried out. Magnetic material (MM) from iron sand was separated using an external magnet, washed with water and HF solution 10%. MM–silica–chitosan material (MMSC) was synthesized via sol gel process and the product was characterized with Fourier Transform Infrared (FT-IR) spectrophotometer, X–ray diffractometer, scanning electron microscopy and energy dispersive X–ray, thermogravimetric analysis, and vibration sample magnetometer. Additionally, the effect of pH on the stability of MMSC has also been tested. The adsorption of Au(III) on MMSC was proceeded in a batch system with variation of pH, contact time, and concentration of absorbate. Adsorbent was separated using external magnet and concentration of Au(III) not adsorbed was analyzed using Atomic Absorption Spectrometer. Characterization result indicated that MMSC was successfully synthesized. Adsorption of Au(III) on MMSC followed pseudo second-order kinetic model with the value of adsorption rate constant (k) of 4.10 x 10-3 g mg-1 min-1 and adsorption isotherm fixed with Langmuir model with the adsorption capacity (qmax) of 149.25 mg g-1.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mingjie Ma ◽  
Weijie Guo ◽  
Zhengpeng Yang ◽  
Shanxiu Huang ◽  
Guanyu Wang

TiO2/fine char (FC) photocatalyst was prepared via sol-gel method with tetrabutyl titanate as the precursor and FC as the carrier. The structural property of TiO2/FC photocatalyst was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the photocatalytic activity of TiO2/FC was evaluated by photocatalytic degradation of rhodamine B (RhB) aqueous solution under UV light irradiation. The results showed that TiO2was successfully coated on the surface of FC, and the TiO2/FC photocatalyst had better photocatalytic efficiency and stability for degradation of RhB under UV light illumination as compared to that of the pure TiO2and FC. The study provided a novel way for the application of FC to the photocatalytic degradation of organic wastes.


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.


2014 ◽  
Vol 807 ◽  
pp. 65-79 ◽  
Author(s):  
Augustine Amalraj ◽  
P. Anitha Pius

The photodegradation of Reactive Red 141 (RR-141) and Reactive Yellow 105 (RY-105) dyes using TiO2 nanoparticles was investigated under UV light irradiation. TiO2 was prepared by sol-gel process and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with Energy Dispersive X-ray analysis (EDAX) and FTIR. The effects of operational parameters such as illumination time, catalyst dose, initial concentration and pH of dye solutions on photodegradation by TiO2 have been analyzed. The degradation of the selected dyes followed pseudo-first order reaction according to the Langmuir-Hinshelwood kinetic model.


2016 ◽  
Vol 864 ◽  
pp. 128-133
Author(s):  
Ardiansyah Taufik ◽  
Shofianina Djalaluidin ◽  
Rosari Saleh

Magnetic heterogeneous Fe3O4/TiO2/CuO catalyst were synthesized using sol-gel method. The molar ratio of Fe3O4/TiO2/CuO were varied from 1:1:0.1 until 1:1:5. The all synthesized catalyst were characterized using X-ray Diffraction (XRD), Energy Dispersive X-ray (EDX), Field Emission Scanning Electron Microscope (FE-SEM), and Vibrating Sample Magnetometer (VSM). The result show that the magnetic heterogeneous Fe3O4/TiO2/CuO catalyst exhibit ferromagnetic behavior under room temperature. The catalytic performance were evaluated on the degradation of methylene blue under UV light and combination of ultrasound and UV-light Irradiation. The combination of ultrasound and UV-light irradiation exhibit batter catalytic performance than ultrasound irradiation only. The Magnetic heterogeneous Fe3O4/TiO2/CuO with molar ratio 1:1:0.1 shows highest catalytic performance. The reusability of catalyst were also observed.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2174
Author(s):  
Melek Koç Keşir ◽  
Münevver Sökmen ◽  
Zekeriya Bıyıklıoğlu

Dye sensitization on semiconductor catalyst TiO2 was performed with four different metallophthalocyanine (MPc) derivates (M: Zn, Cu, Co, and Si) using a modified sol-gel method. MPc derivatives were loaded on TiO2 at 1% mass ratio aiming to increase its photocatalytic action and to shift the light absorption to higher UV region (365 nm). Non-ionic surfactant Triton X-100 (TX-100) was used to obtain a homogenous and mesa pore catalyst structure. The prepared catalysts were characterized by FT-IR, XRD, and SEM to determine the crystal and surface structural properties of nanocomposites. The nanocomposites were used for photocatalytic removal and degradation of Cr(VI) and amoxicillin (AMX) as model pollutants. Photocatalytic reduction capacities of the catalysts were tested for Cr(VI) (10 mg/L) and AMX (20 mg/L) aqueous solutions. ZnPc-TiO2 catalyst was successful for Cr(VI) photoreduction since all Cr(VI) ions in the solution were successfully removed. Presence of TX-100 in the sol-gel synthesis of ZnPc-TiO2 had a positive effect by increasing the Cr(VI) removal rate to 97.93% after 150 min exposure period. Prepared catalysts were also tested for photodegradation of AMX, applying similar procedures. In general, all catalysts exhibited low degradation rates under the studied condition but more effective with 254 nm UV light (50.38%). Neither surface modification with TX-100 nor MPc sensitization provided significant degradation of AMX.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Yan ◽  
Yanhua Shen ◽  
Feng Li ◽  
Taohai Li

High crystallinity of ZnWO4nanoparticles has been successfully synthesized via a highly effective and environmentally friendly microwave route by controlling the reaction time and temperature. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Fourier infrared spectrum (FT-IR). The crystallinity was enhanced with the increase of the reaction temperature and time. The photocatalytic activities of ZnWO4nanocrystals were evaluated by testing the photodegradation of rhodamine B (RhB) dye under ultraviolet (UV) light irradiation. The results indicated that as-prepared ZnWO4was highly effective for the degradation of RhB. The degradation rate of RhB reached 98.01% after 6 h of UV illumination.


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