scholarly journals Photocatalytic Abatement of Volatile Organic Compounds by TiO2 Nanoparticles Doped with Either Phosphorous or Zirconium

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2121 ◽  
Author(s):  
Melodj Dosa ◽  
Marco Piumetti ◽  
Samir Bensaid ◽  
Tahrizi Andana ◽  
Camilla Galletti ◽  
...  

The aim of this work is to study the activity of novel TiO2-based photocatalysts doped with either phosphorus or zirconium under a UV-Vis source. A set of mesoporous catalysts was prepared by the direct synthesis: TiO2_A and TiO2_B (titanium oxide synthesized by two different procedures), P-TiO2 and Zr-TiO2 (binary oxides with either nonmetal or metal into the TiO2 framework). Complementary characterizations (N2 physisorption at 77 K, X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) analysis, X-ray Photoelectron Spectroscopy (XPS), and (DR)UV-Vis spectroscopy) were used to investigate the physicochemical properties of the prepared catalysts. Then, the photocatalysts were tested for the oxidation of propylene and ethylene under UV-Vis light. As a result, the most promising catalyst for both the propylene and ethylene oxidation reactions was the P-TiO2 (propylene conversion = 27.8% and ethylene conversion = 13%, TOS = 3 h), thus confirming the beneficial effect of P-doping into the TiO2 framework on the photocatalytic activity.

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1456
Author(s):  
Yujie Fu ◽  
You Zhang ◽  
Qi Xin ◽  
Zhong Zheng ◽  
Yu Zhang ◽  
...  

Chlorinated volatile organic compounds (CVOCs) are vital environmental concerns due to their low biodegradability and long-term persistence. Catalytic combustion technology is one of the more commonly used technologies for the treatment of CVOCs. Catalysts with high low-temperature activity, superior selectivity of non-toxic products, and resistance to chlorine poisoning are desirable. Here we adopted a plasma treatment method to synthesize a tin-doped titania loaded with ruthenium dioxide (RuO2) catalyst, possessing enhanced activity (T90%, the temperature at which 90% of dichloromethane (DCM) is decomposed, is 262 °C) compared to the catalyst prepared by the conventional calcination method. As revealed by transmission electron microscopy, X-ray diffraction, N2 adsorption, X-ray photoelectron spectroscopy, and hydrogen temperature-programmed reduction, the high surface area of the tin-doped titania catalyst and the enhanced dispersion and surface oxidation of RuO2 induced by plasma treatment were found to be the main factors determining excellent catalytic activities.


Author(s):  
I-Hsuan Chen ◽  
Jung-Hsien Chang ◽  
Ren-Jie Xie ◽  
Chia-Hui Tseng ◽  
Sheng-Rong Hsieh ◽  
...  

Abstract In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.


2021 ◽  
Vol 314 ◽  
pp. 23-28
Author(s):  
Seungjun Oh ◽  
Sunyoung Lee ◽  
Heehwan Kim ◽  
Donggeon Kwak ◽  
Chulwoo Bae ◽  
...  

Technological control over ultra-trace level contaminants is important for semiconductor development. Despite technological developments, defects remain in the single wafer wet cleaning process. In this paper, the source of the contamination is explained via trace analytical methods. Fluorine resin materials of polytetrafluoroethylene (PTFE) and ethylene tetrafluoroethylene (ETFE) are commonly used in semiconductor equipment. Isopropyl alcohol (IPA) oxidation reactions occur at high temperature below the boiling point due to impurities. IPA changed to different alcohol forms from gas chromatography (GCMS) analysis. The oxygen concentration in the X-ray photoelectron spectroscopy (XPS) results increased and formed new bonds in IPA with fluorine resin. These reactions confirmed that cations were a catalyst from the time-of-flight secondary ion mass spectrometry (TOF-SIMS) results. Representative ions were Fe+, K+, and Na+ with different concentrations for each material.


2011 ◽  
Vol 89 (7) ◽  
pp. 845-853 ◽  
Author(s):  
Sadok Letaief ◽  
Wendy Pell ◽  
Christian Detellier

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.


Author(s):  
Katarzyna Matras-Postolek ◽  
A. Zaba ◽  
S. Sovinska ◽  
D. Bogdal

Zinc sulphide (ZnS) and zinc selenide (ZnSe) and manganese-doped and un-doped with different morphologies from 1D do 3D microflowers were successfully fabricated in only a few minutes by solvothermal reactions under microwave irradiation. In order to compare the effect of microwave heating on the properties of obtained  nanocrystals, additionally the synthesis under conventional heating was conducted additionally in similar conditions. The obtained nanocrystals were systematically characterized in terms of structural and optical properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The photocatalytic activity of ZnSe, ZnS, ZnS:Mn and ZnSe:Mn nanocrystals with different morphologies was evaluated by the degradation of methyl orange (MO) and Rhodamine 6G (R6G), respectively. The results show that Mn doped NCs samples had higher coefficient of degradation of organic dyes under ultraviolet irradiation (UV).


2019 ◽  
Vol 41 (2) ◽  
pp. 308-308
Author(s):  
Fangyan Chen Fangyan Chen ◽  
Yiming Liu Yiming Liu ◽  
Xi Zhang Xi Zhang ◽  
Lina He and Yubin Tang Lina He and Yubin Tang

In order to improve the photocatalytic efficiency and selectivity of di (2-ethylhexyl) phthalate (DEHP) under solar-driven, the inorganic-framework molecularly imprinted CdS/TiO2, named as MIP-CdS/TiO2, was prepared by using DEHP as template molecule and tetrabutyl titanate as titanium source and functional monomer. The as-prepared MIP-CdS/TiO2 was characterized by scanning electron microscopy (SEM), X-ray energy spectrum (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis Spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectrum (PL). And the specific recognition and photocatalytic selectivity of MIP-CdS/TiO2 to DEHP were investigated. The results show that inorganic-framework molecular imprinting on the surface of CdS/TiO2 can result in existence of specific recognition sites of DEHP, extend and intensify the absorption visible light of CdS/TiO2, inhibit the recombination of the photo-induced electron-holes pairs. MIP-CdS/TiO2 has a specific recognition to DEHP. The binding selectivity coefficients of DEHP relative to its analogues DBP and DMP are 2.78 and 2.60, respectively. Compared with CdS/TiO2, MIP-CdS/TiO2 exhibits higher photocatalytic activity and selectivity for DEHP. Under simulated solar light irradiation, the degradation efficiency of DEHP photocatalyzed by MIP-CdS/TiO2 is 75.5%, which is 1.63 times as high as that of DEHP photocatalyzed by CdS/TiO2.


2013 ◽  
Vol 734-737 ◽  
pp. 2163-2167
Author(s):  
Guang Xiu Cao ◽  
Zhong Hou Zhang ◽  
Bin Zhai

Lanthanum doped TiO2 powders were prepared by hydrolysis of titanium tetra-n-butyl oxide and La (NO3)3 in solution. The resulting powders were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis absorption spectroscopy. The photocatalytic activities of doped samples were evaluated by the decomposition of methylene blue under visible light irradiation. The XRD results showed that the doping of lanthanum could not only efficiently inhibit the grain growth but also suppress the phase transition of anatase to rutile. UV-Vis spectroscopy of lanthanum doping TiO2 indicated that the absorption onset red-shifted to the visible light region. XPS results revealed that La2O3 had formed which could enhance the surface area. The degradation rates of methylene blue verified that the visible light photocatalytic activity of TiO2 has been enhanced by the doping of lanthanum.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 937 ◽  
Author(s):  
Roberto Nasi ◽  
Serena Esposito ◽  
Francesca Freyria ◽  
Marco Armandi ◽  
Tanveer Gadhi ◽  
...  

TiO2 nanoparticles containing 0.0, 1.0, 5.0, and 10.0 wt.% Mo were prepared by a reverse micelle template assisted sol–gel method allowing the dispersion of Mo atoms in the TiO2 matrix. Their textural and surface properties were characterized by means of X-ray powder diffraction, micro-Raman spectroscopy, N2 adsorption/desorption isotherms at −196 °C, energy dispersive X-ray analysis coupled to field emission scanning electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance UV–Vis spectroscopy, and ζ-potential measurement. The photocatalytic degradation of Rhodamine B (under visible light and low irradiance) in water was used as a test reaction as well. The ensemble of the obtained experimental results was analyzed in order to discover the actual state of Mo in the final materials, showing the occurrence of both bulk doping and Mo surface species, with progressive segregation of MoOx species occurring only at a higher Mo content.


2015 ◽  
Vol 1131 ◽  
pp. 35-38
Author(s):  
Navaphun Kayunkid ◽  
Annop Chanhom ◽  
Chaloempol Saributr ◽  
Adirek Rangkasikorn ◽  
Jiti Nukeaw

This research is related to growth and characterizations of indium-doped pentacene thin films as a novel hybrid material. Doped films were prepared by thermal co-evaporation under high vacuum. The doping concentration was varied from 0% to 50% by controlling the different deposition rate between these two materials while the total thickness was fixed at 100 nm. The hybrid thin films were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-Visible spectroscopy to reveal the physical and optical properties. Moreover, the electrical properties of ITO/indium-doped-pentacene/Al devices i.e. charge mobility and carrier concentration were determined by considering the relationship between current-voltage and capacitance-voltage. AFM results identify that doping of indium into pentacene has an effect on surface properties of doped films i.e. the increase of surface grain size. XRD results indicate that doping of metal into pentacene has an effect on preferential orientation of pentacene’s crystalline domains. UV-Vis spectroscopy results show evolution of absorbance at photon energy higher than 2.7 eV corresponding to absorption from oxide of indium formed in the films. Electrical measurements exhibit higher conductivity in doped films resulting from increment of both charge carrier mobility and carrier concentration. Furthermore, chemical interactions taken place inside the doped films were investigated by x-ray photoelectron spectroscopy (XPS) in order to complete the remaining questions i.e. how do indium atoms interact with the neighbor molecules?, what is the origin of the absorption at E > 2.7 eV? Further results and discussions will be presented in the publication.


Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 581 ◽  
Author(s):  
Sonam Goyal ◽  
Maizatul Shaharun ◽  
Chong Kait ◽  
Bawadi Abdullah ◽  
Mariam Ameen

The efficient reduction of CO2 into valuable products such as methanol, over metal-organic frameworks (MOFs) based catalyst, has received much attention. The photocatalytic reduction is considered the most economical method due to the utilization of solar energy. In this study, Copper (II)/Zeolitic Imidazolate Framework-8 (Cu/ZIF-8) catalysts were synthesized via a hydrothermal method for photocatalytic reduction of CO2 to methanol. The synthesized catalysts were characterized by X-ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray (EDX), Ultraviolet-visible (UV-vis) spectroscopy, and X-Ray Diffraction (XRD). The host ZIF-8, treated with 2 mmol copper prepared in 2M ammonium hydroxide solution showed the highest photocatalytic activity. The crystal structures of ZIF-8 and 2Cu/ZIF-8N2 catalysts were observed as cubic and orthorhombic, respectively and the XPS analysis confirmed the deposition of Cu (II) ions over ZIF-8 surface among all the prepared catalysts. The orthorhombic structure, nano-sized crystals, morphology and Cu loading of the 2Cu/ZIF-8N2 catalyst were the core factors to influence the photocatalytic activity. The yield of Methanol was found to be 35.82 µmol/L·g after 6 h of irradiations on 2Cu/ZIF-8N2 catalyst in the wavelength range between 530–580 nm. The copper-based ZIF-8 catalyst has proven as an alternative approach for the economical photocatalytic reduction of CO2 to CH3OH.


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