scholarly journals Application of Novel C-TiO2-CFA/PAN Photocatalytic Membranes in the Removal of Textile Dyes in Wastewater

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 909
Author(s):  
Amkelwa Mpelane ◽  
David M. Katwire ◽  
Henry H. Mungondori ◽  
Pardon Nyamukamba ◽  
Raymond T. Taziwa

The existence of dye effluent in environmental water bodies is becoming a growing concern to environmentalists and civilians due to negative health effects. In this study, a novel poly(acrylonitrile)-membrane-supported carbon-doped titanium dioxide–coal fly ash nanocomposite (C-TiO2-CFA/PAN) was prepared and evaluated in the removal of textiles dyes (methyl orange and golden yellow) in water. The C-TiO2-CFA nanocomposite was prepared via sol-gel synthesis and immobilized on PAN membrane prepared via phase inversion technique. The photocatalyst was characterized by FTIR, XRD, BET surface area analysis, SEM, EDX, and DRS. FTIR analysis confirmed the existence of the expected functional groups, and XRD revealed that the C-TiO2 was predominantly in the anatase phase, which exhibited the highest photocatalytic activity. The optimum C-TiO2-CFA photocatalyst load on the PAN membrane was 2% w/w, and it achieved degradation efficiencies of 99.86% and 99.20% for MO and GY dyes, respectively, at pH 3.5, using a dye concentration of 10 ppm, under sunlight irradiation, in 300 min. The novel 2% C-TiO2-CFA/PAN photocatalytic membrane proved to be very effective in the removal of textile dyes’ water. Three reusability cycles were carried out, and no significant changes were observed in the photocatalytic efficiencies. Immobilization on PAN membrane allowed easy recovery and reuse of the photocatalyst.

2016 ◽  
Vol 2 (1) ◽  
pp. 23-30 ◽  
Author(s):  
O.S.N. Ghosh ◽  
◽  
S. Gayathri ◽  
D. Alagarasan ◽  
K.V.P. Kumar ◽  
...  

2014 ◽  
Vol 1675 ◽  
pp. 203-208 ◽  
Author(s):  
Rahul R. Bhosale ◽  
Ivo Alxneit ◽  
Leo L. P. van den Broeke ◽  
Anand Kumar ◽  
Mehak Jilani ◽  
...  

ABSTRACTIn this contribution, we report the synthesis and characterization of NixFe3-xO4 and CoxFe3-xO4 redox nanomaterials using sol-gel method. These materials will be used to produce solar fuels such as H2 or syngas from H2O and/or CO2 via solar thermochemical cycles (STCs). For the sol-gel synthesis of ferrites, the Ni, Co, Fe precursor salts were dissolved in ethanol and propylene oxide (PO) was added dropwise to the well mixed solution as a gelation agent to achieve gel formation. Freshly synthesized gels were aged, dried, and calcined by heating them to 600°C in air. The calcined powders were characterized by powder x-ray diffractometer (XRD), BET surface area, as well as scanning (SEM) and transmission (TEM) electron microscopy. Their suitability to be used in STCs for the production of solar fuels was assessed by performing several reduction/re-oxidation cycles using a thermogravimetric analyzer (TGA).


2012 ◽  
Vol 503-504 ◽  
pp. 646-649
Author(s):  
Xiao Ling Guo ◽  
Xiang Dong Wang ◽  
De Ping Ben

Nano-TiO2 powders were synthesized by a sol-gel method using tetrabutyl titanate as the precursor, and then the composites of ACF(activated carbon fiber) supported nano-TiO2 was prepared by impregnating method. Tests of the amount of loaded TiO2 showed that three impregnating times was adequate. The Nano-TiO2 powders and composites were characterized by XRD, SEM, and BET surface area method. XRD tests showed that nano-TiO2 powders prepared by this way are anatase phase, and the mean size of the particles is about 11.5nm, when the calcination temperature is 673K. BET results showed that compared with original ACF, the surface area of the composites decreased slightly, indicating the impregnating process did not change the porous structure of original ACF. SEM result indicated that most of the nano-TiO2 particles as the size of 10-20nm were homogeneously dispersed on the surface of ACF.


2016 ◽  
Vol 22 (1) ◽  
pp. 65-73
Author(s):  
Aleksandar Golubovic ◽  
Ivana Veljkovic ◽  
Maja Scepanovic ◽  
Mirjana Grujic-Brojcin ◽  
Natasa Tomic ◽  
...  

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis like the temperature (500 and 550 ?C) and the duration of the calcination (1.5, 2, and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders are dominantly in anatase phase, with the presence of a small amount of rutile in samples calcined at 550 ?C. According to the results obtained by Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), carbofuran and phenol.


2021 ◽  
Vol 11 (4) ◽  
pp. 51-75
Author(s):  
Dalya Jasim Ahmed Ahmed ◽  
Basim Ibrahim Al-abdaly ◽  
Sattar Jalil Hussein

TiO2 and TiO2-Al2O3 nanoparticles were synthesized via sol-gel method using hydrolysis of Titanium tetraisopropoxide (TTIP) with ethanol and water mixture as titania source. TiO2-Al2O3 Nano-composite was successfully synthesized using the sol-gel technique. Tetraisopropoxide and aluminium isopropoxide were used to prepare TiO2-Al2O3. All prepared samples calcination were conducted at different temperature (400 to 700) oC. The synthesized TiO2 and TiO2-Al2O3 nanocomposites were then characterized by XRD, AFM, BET surface area, SEM, XRF. XRD, the analysis showed that the presence of alumina (Al2O3) in the TiO2 has an effect on crystal size, particles size, surface area, and crystal phases; The XRD result revealed that the prepared TiO2 nanoparticles were anatase phase at 400oC, and 500oC, and transformed to rutile from 600oC to 700oC, but after addition of alumina TiO2 was of anatase phase, without any rutile at all calcination temperatures, also, the addition of alumina leads to a significant decrease in the crystal size, particles size, especially at high temperatures while the surface area of pure titanium was increased, and this corresponds to the results of the AFM and SEM. The best-obtained surface area was 355.18 m2/ gm. with 34.98 nm of average particle size at 500oC in comparison with pure nano titanium dioxide


2013 ◽  
Vol 864-867 ◽  
pp. 613-616
Author(s):  
Xue Mei Qi ◽  
Xin Yuan Zhu ◽  
Jiang Wu ◽  
Yu Wu ◽  
Han Cheng Luo

The TiO2-based photocatalysts have been synthesized by using sol-gel process and their photocatalytic activities were studied by the degradation of methylene blue (MB). It was shown that the calcination temperature has great influence on the crystalline phase transition of TiO2. For all the samples (Ag-doped and undoped TiO2photocatalysts) calcined at 573K, only anatase phase was observed from XRD diffraction spectra and the intensity of peaks is weak. After the calcined at 773K, a mixture of anatase-rutile phase appeared. The contents of rutile phase were about 85% and77% for undoped and Ag-adopted TiO2photocatalysts.There were only rutile phases for all the TiO2photocatalysts calcined at 973K observed from XRD diffraction spectra. Magnetically stirring time of A solution before added B had no obvious effects on the polymorphs transition of TiO2.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1369
Author(s):  
Jadra Mosa ◽  
Mario Aparicio

The development of anodes based on Li4Ti5O12 (LTO) for lithium ion batteries has become very important in recent years on the basis that it allows a long service life (stability in charge-discharge cycling) and safety improvements. The processing of this material in the form of thin film allows for greater control of its characteristics and an improvement of its disadvantages, namely reduced electrical conductivity and low diffusion of lithium ions. In this work, we try to limit these disadvantages through the synthesis of a mesostructured carbon-doped Li4Ti5O12 thin-film with a pure spinel phase using a combination of a block-copolymer template and in situ synthesis of Li-Ti double alkoxide. Structural and electrochemical characterization has been carried out to determine the best conditions (temperature, time, atmosphere) for the thermal treatment of the material to reach a compromise between crystallinity and porosity distribution (pore size, pore volume, and interconnectivity).


2012 ◽  
Vol 712 ◽  
pp. 117-131 ◽  
Author(s):  
Ananta Kumar Karki ◽  
Nurak Grisdanurak ◽  
Siriluk Chiarakorn

TiO2thin film enhanced by diethanolamine (DEA) and MCM-41 (D-TiO2/MCM-41) was successfully synthesized by sol-gel dip coating technique on glass slides. The roles of DEA and MCM-41 on physical and photocatalytic characteristics of the films were studied using various techniques such as x-ray defraction (XRD), fourier transform infrared spectroscopy (FTIR), ultra violet-visible (UV-Vis) spectrometry, Brunauer, Emmett and Teller (BET) surface area analysis and field emission scanning electron microscope (FESEM). The XRD results showed that the thin film contained almost 100% anatase phase and the crystal size of TiO2was in the range of 4-8 nm. The FTIR spectra indicated the formation of Ti-O-Si and Si-O-Si linkages due to interaction of TiO2and MCM-41. The surface area of TiO2was increased significantly when MCM-41 was added. The use DEA and MCM-41 caused slight increase in visible light absorption but UV absorption was decreased. The photocatalytic reactivity of the thin film was tested by photocatalytic degradation of methylene blue under visible light. The addition of DEA as a nitrogen source was beneficial not only for obtaining stable/smooth surface of the thin film but also for enhancing photocatalysis of methylene blue by preventing charge carrier recombination. While MCM-41 played important functions in improving porosity and hydrophilicity of the film. The photodegradation of methylene blue was obtained up to 35% of its original concentration when 1M DEA and 0.3M MCM-41 were incorporated in TiO2thin film. The overall enhancement of photocatalytic activity of the film was a result of nitrogen doping, increased surface area as well as increased hydrophilicity provided by MCM-41.


2015 ◽  
Vol 1123 ◽  
pp. 96-99
Author(s):  
Is Fatimah ◽  
Zulfa Zuhrufa

The sulfated zirconia catalysts were was prepared by sol–gel processes consist of varied templating method. Both preparations consist of sol-gel synthesis of zirconium dioxide followed by sulfatation process by using NH4SO4solid reaction method. Two different templating agent; urea and cetyltrimetyl ammonium bromide was used in sol-gel processes. The prepared material was characterized using scanning electron microscope (SEM), x-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) measurements. From the XRD measurement it can be concluded that both materials consist of ZrO2in combined phases while from BET surface area analysis it can be noted that material prepared by urea template has higher specific surface area compared to that use CTAB template. Both materials exhibit the activity as acid catalyst in microwave assisted conversion of citronellal. It is also confirmed that the higher the surface area the higher total conversion of citronellal obtained. Study on the correlation between physicochemical properties of materials with the catalytic activity was discussed in this paper.


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