scholarly journals Mesoporous Ce-doped Ti:Ash Photocatalyst Investigation in Visible Light Photocatalytic Water Pretreatment Process

2020 ◽  
Vol 15 (2) ◽  
pp. 367-378
Author(s):  
Abdulkarim Abdulrahman Mohamed Suliman ◽  
Ruzinah Isha ◽  
Mazrul Nizam Abu Seman ◽  
Abdul Latif Ahmad ◽  
Jamil Roslan

The treatment of organic pollutants in water including semiconductor photocatalysis is a promising approach to disinfect water. The objective of this study is to investigate the effect of Ce loaded on mesoporous Ti:Ash catalyst for water pretreatment process. The mesoporous Ti:Ash catalyst that doped with Ce was synthesized through wet impregnation method with 5%, 10%, and 15% weight percentage of Ce doped on 40:60 Ti:Ash. The photocatalytic properties were characterized through X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2 adsorption-desorption studies and diffuse reflectance UV–vis absorption spectroscopy. It is found that the Ti:Ash nanocomposites doped with Ce shifted the light absorption band-edge position to the visible region. Moreover, the Ce doped Ti:Ash has large surface area and pore diameter. The Ce doping could significantly improve the absorption edge of visible light and adjust the cut-off absorption wavelength from 404 nm to 451, 477 and 496 nm for 5%, 10% and 15% Ce-doped mesoporous Ti:Ash catalysts, respectively. As the Ce doping ratio increased, the band gaps decreased from 3.06 eV to 2.53 eV. The most contaminant reduction up to 45% was achieved when Ti:Ash:Ce 40:55:5 was used. Higher Ce loading on the photocatalyst may reduce the photocatalyst performance because supernumerary metal loading on TiO2 can block TiO2 defect sites which are necessary for the adsorption and photoactivation. The OPFA also acts as an adsorbent for some pollutants besides, reducing the water salinity. It can be deduced that the hybrid TiO2 photocatalyst that synthesized with OPFA and doped with Ce has huge potential to treat seawater prior to commercial seawater desalination process. Copyright © 2020 BCREC Group. All rights reserved 

2013 ◽  
Vol 845 ◽  
pp. 421-425 ◽  
Author(s):  
Raihan Mahirah Ramli ◽  
Chong Fai Kait ◽  
Abdul Aziz Omar

Titania nanoparticles, TiO2 were synthesized via microemulsion method prior to monometallic (Fe, Cu) or bimetallic (CuFe) incorporation using wet impregnation method. The prepared photocatalysts were characterized using X-ray diffraction, field emission scanning electron microscopy, diffuse reflectance UV-Vis spectroscopy and point of zero charge. The addition of metals, especially Cu enhanced the absorbance in the visible region. The lowest band gap was observed for the bimetallic Cu-Fe/TiO2 (2.77 eV) compared to bare TiO2 (3.05 eV). The performance of the photocatalysts for photodegradation of diisopropanolamine (DIPA) at pH 8 was determined using a batch glass reactor under simulated sunlight (980 W/m2). The best performance was displayed by Cu-Fe/TiO2 with the highest DIPA removal of 92%.


2019 ◽  
Vol 948 ◽  
pp. 221-227
Author(s):  
Latifah Hauli ◽  
Karna Wijaya ◽  
Ria Armunanto

Catalyst of Chromium (Cr) metal supported on sulfated zirconia (SZ) was prepared by wet impregnation method. This study aim to determine the optimal concentration of Cr metal that impregnated on SZ catalyst. Preparation of catalyst was conducted at different concentrations of Cr metal (0.5%, 1%, 1.5% (w/w)), impregnated on SZ catalyst, then followed by the calcinationand reduction process. Catalysts were charaterized by FTIR, XRD, XRF, SAA, TEM, and acidity test. The results showed the Cr/SZ 1% had the highest acidity value of 8.22 mmol/g which confirmed from FTIR spectra. All the crystal phase of these catalysts were in monoclinic. The specific surface area increased with the increasing of Cr metal concentration on SZ catalyst and the isotherm adsorption-desorption of N2 gas observed all the catalysts as mesoporous material. The impregnation process formed particles agglomeration.


Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 947 ◽  
Author(s):  
Edson Edain González ◽  
Ricardo Rangel ◽  
Javier Lara ◽  
Pascual Bartolo-Pérez ◽  
Juan José Alvarado-Gil ◽  
...  

Nowadays, one of the most important challenges that humanity faces is to find alternative ways of reducing pollutant emissions. CeO2/Bi2Mo1−xRuxO6 and Au/Bi2Mo1−xRuxO6 catalysts were prepared to efficiently transform carbon monoxide (CO) to carbon dioxide (CO2) at low temperatures. The systems were prepared in a two-step process. First, Bi2Mo1−xRuxO6 supports were synthesized through the hydrothermal procedure under microwave heating. Then, CeO2 was deposited on Bi2Mo1−xRuxO6 using the wet impregnation method, while the incipient impregnation method was selected to deposit gold nanoparticles. The CeO2/Bi2Mo1−xRuxO6 and Au/Bi2Mo1−xRuxO6 catalysts were characterized using SEM microscopy and XRD. Furthermore, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used. Tests were carried out for the supported catalysts in CO oxidation, and high conversion values, nearing 100%, was observed in a temperature range of 100 to 250 °C. The results showed that the best system was the Au/Bi2Mo0.95Ru0.05O6 catalyst, with CO oxidation starting at 50 °C and reaching 100% conversion at 186 °C.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Ma ◽  
Jia Chu ◽  
Liangsheng Qiang ◽  
Juanqin Xue

The new novel material Bi-TiO2/SBA-15 was synthesized by an easy wet impregnation method. A combination of XRD, XPS, Raman, N2adsorption-desorption isotherm measurement, TEM, and solid state UV-Vis spectroscopy has been used to characterize the Bi-TiO2/SBA-15 material. It was found that SBA-15 retained the ordered hexagonal mesostructure after incorporation of TiO2and Bi. The photodecomposition of rhodamine B (RhB) in aqueous medium was selected to evaluate the photocatalytic performance of Bi-TiO2/SBA-15 under visible light irradiation (λ≥420 nm). The experiment results indicated that Bi-TiO2/SBA-15 exhibited higher photocatalytic activities than pure TiO2and Bi2O3. The influences of calcination temperature were studied. It strongly influenced the activity of the samples. The sample calcined at 550°C shows the highest photocatalytic activity in the decomposition of RhB under visible light. The catalyst preserved almost its initial photocatalytic activity after six reuses.


2019 ◽  
Vol 9 (17) ◽  
pp. 4598-4613 ◽  
Author(s):  
Niwesh Ojha ◽  
Abhinav Bajpai ◽  
Sushant Kumar

We synthesized Cu modified S-doped g-C3N4 thin sheets using calcination followed by a wet-impregnation method. The photocatalytic activity was studied for reduction of CO2 to CO and CH4 in the presence of water and a plausible mechanism is explained.


Author(s):  
Nina Haryani ◽  
Taslim Taslim ◽  
Irvan ◽  
Renita Manurung ◽  
Rondang Tambun

Biofuels as environmentally friendly alternative fuels such as biogasoline, biokerosene and others are generally obtained through a cracking process and take place more effectively to attend a catalyst. In this study, the synthesis of ZnO/ZSM-5 aims to obtain a catalyst that can be used in the cracking process of Palm Methyl Esters (PME) into hydrocarbon fuels especially biogasoline. This catalyst is environmentally friendly, easy to separate, has good selectivity, and can increase the conversion of cracking products. The wet impregnation method followed by drying and calcination is the method used to synthesize the catalyst. Furthermore, several analyzes were carried out to determine the characteristics of the catalyst. The analysis is the Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), X-Ray Diffraction (XRD), N2 adsorption-desorption with BET-BJH, Temperature Programmed Desorption-NH3 (TPD-NH3) and the Temperature Programmed Reduction (TPR). Based on synthesis results obtained ZnO/ZSM-5 catalyst with ZnO content of 11.77 wt%, 13.61 wt% and 18.22 wt%. The use of this catalyst in the cracking process can result in the conversion of liquid fuel by 88.57%, heavy hydrocarbon (8.57%) and gas product (2.86%).


2011 ◽  
Vol 396-398 ◽  
pp. 2033-2037 ◽  
Author(s):  
Zhi Fang Jia ◽  
Fu Min Wang ◽  
Ying Bai ◽  
Ning Liu

The InVO4-based photocatalysts loaded with metal oxides (Fe2O3, CuO, NiO) were synthesized by wet impregnation method. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy(SEM), UV-vis diffuse reflectance spectroscopy(DRS). The influence of different metal oxides loading (Fe2O3, CuO, NiO) on the photocatalytic activity for photocatalytic reduction of CO2 was discussed. It is found that Fe2O3-loaded InVO4 significantly enhance the methanol yield through promoting the effective separation of photoinduced electron-hole pairs.


2020 ◽  
Vol 9 (1) ◽  
pp. 80-89
Author(s):  
Juliana F. Gonçalves ◽  
Mariana M.V.M. Souza

Background: Hydrogen has been considered the energy source of the future and one of the processes for its production is the methane steam reforming. The catalyst used industrially is Ni/Al2O3 and the addition of promoter oxides can be an alternative to improve the performance of this catalyst, which suffers from coke formation and sintering. Objective: Evaluate the role of niobia on catalytic activity and stability. Methods: Ni/x%Nb2O5/Al2O3 (x = 5, 10 and 20) catalysts were synthesized via coprecipitation-wet impregnation method and characterized by X-ray fluorescence (XRF), N2 adsorption-desorption, X-ray diffraction (XRD), temperature- programmed reduction (TPR), temperature-programmed desorption of ammonia (TPD-NH3), etc. Finally, the catalysts were tested for methane steam reforming reaction. Results: All niobia-doped catalysts presented similar values of methane conversion and when comparing with Ni-Al, the addition of niobia slightly improved the methane conversion. In the stability test at 800oC, all doped and non-doped catalysts did not deactivate during the 24 h of reaction. Conclusion: The addition of 10 and 20 wt.% of niobia had a significant promoter effect over Ni/Al2O3 catalyst in terms of activity and stability at 800 oC and the sample with 20 wt.% of niobia presented lower coke formation.


2014 ◽  
Vol 917 ◽  
pp. 160-167 ◽  
Author(s):  
Raihan Mahirah Ramli ◽  
Chong Fai Kait ◽  
Abdul Aziz Omar

Photodegradation of 100 ppm diisopropanolamine (DIPA) was studied employing heterogeneous photo-Fenton system using iron modified TiO2 photocatalyst. A series of Fe/TiO2 photocatalysts were prepared via hydrolysis-hydrothermal and wet impregnation methods. Photocatalysts prepared using wet impregnation method was found to have similar activity under both UV and visible light. Addition of H2O2 during the photodegradation study obviously promoted the COD removal efficiency. When stoichiometric concentration of H2O2 was added, as high as 80% of COD was removed within 1.5 h reaction. Further modification is required to increase the photocatalyst performance in photodegradation of DIPA.


2015 ◽  
Vol 1089 ◽  
pp. 133-136 ◽  
Author(s):  
Zhi Dan Fu ◽  
Qing Ye ◽  
Shui Yuan Cheng ◽  
Dao Wang

The manganese oxide (MnO2) sample was synthesized by the reaction of KMnO4 with Mn (Ac)2 using the HNO3 solution as pH regulator. The Ag-doped manganese oxide, Ag/MnO2-Q and Ag/MnO2-H, were synthesized by incorporation method and typical wet impregnation method, respectively. The structure of catalysts was characterized by N2 adsorption/desorption and X-ray diffraction. The influences of preparation methods on the catalytic activity of CO oxidation were studied. The doping of Ag to MnO2 decreased the specific surface area of Ag/MnO2 catalysts, especially for Ag/MnO2-H samples prepared by traditional wet-impregnation method. The Ag/MnO2 catalysts showed higher catalytic activity for CO oxidation than that of MnO2. The catalytic activities of Ag/MnO2 samples strongly depended upon the preparing methods, among which 3Ag/MnO2-Q catalyst, prepared by the incorporation method, was the most efficient catalyst towards the addressed reactions. The excellent performance of 3Ag/MnO2-Q was mainly associated with the good low-temperature reducibility, abundant surface oxygen and broadly dispersed silver oxides species.


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