scholarly journals Synthesis of Zinc Oxide Supported on Titanium Dioxide for Photocatalytic Oxidative Desulfurization of Dibenzothiophene

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Hitam, C.N.C. ◽  
Jalil, A.A. ◽  
Triwahyono, S.

Photocatalytic oxidative desulfurization (PODS) has received much attention due to low energy consumption and high efficiency, as well as simple and pollution-free operation. In this study, zinc oxide supported on titanium dioxide (ZnO/TiO2) catalysts were prepared via a simple electrochemical method. The presence of anatase phase TiO2 and wurtzite ZnO was confirmed by X-ray diffraction (XRD) analysis while band gap energies were determined by UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activity was tested for desulfurization of 100 mg/L dibenzothiophene (DBT). The highest desulfurization rate (2.20 × 10-3 mM/min) was achieved using 1 g/L of 10 wt% ZnO/TiO2 after 2 hr under UV irradiation.

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Mukhamad Nurhadi ◽  
Jon Efendi ◽  
Lee Siew Ling ◽  
Teuku Meurah Indra Mahlia ◽  
Ho Chin Siong ◽  
...  

Titanium dioxide supported sulfonated low rank coal catalyst possesses high catalytic activity in liquid phase oxidation of styrene with aqueous hydrogen peroxide at room temperature. The catalysts were prepared by sulfonation with concentrated sulfuric acid and impregnation of titanium dioxide (500-2500 µmol). The effect of titanium dioxide impregnation and calcinations on the catalysts were studied by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, BET surface area, field emission scanning electron microscopy and hydrophobicity measurement. The catalytic activity of the catalysts in the oxidation of styrene by aqueous H2O2 without calcination increased when the amount of titanium dioxide increased. Meanwhile, the catalytic activity of the catalyst calcined at 500oC for 2 h was lower than before calcination. It is suggested that the agglomeration of titanium dioxide and hydrophobicity play important role in the catalytic activity of titanium dioxide-supported sulfonated low rank coal in the oxidation of styrene with aqueous H2O2. 


2013 ◽  
Vol 802 ◽  
pp. 252-256 ◽  
Author(s):  
Chokchai Kahattha ◽  
Naratip Vittayakorn ◽  
Wisanu Pecharapa

Titanium dioxide nanoparticles (TiO2) were successfully synthesized via a sonochemical-assisted process using titanium isopropoxide as the titanium sources and calcination process at 300-500 °C. The effect of sonication time and heat treatment temperature on structural and nanostructure properties of the nanoparticles were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The XRD and Raman results indicated that the crystalline of as-sonochemically synthesized TiO2 nanoparticles corresponded to anatase phase of TiO2 after sonication for 30 mim. The high quality crystalline anatase phase and increasing of crystalline size can be obtained after calcinations process.


2020 ◽  
Vol 307 ◽  
pp. 185-191
Author(s):  
Noor Syafiqah Samsi ◽  
N.A.S. Affendi ◽  
M.K. Yaakob ◽  
M.F.M. Taib ◽  
A. Lepit ◽  
...  

Graphene-Zinc Oxide (Gr-ZnO) nanocomposites films were successfully synthesized via facile electrodeposition method in an aqueous solution under Gr concentration conditions. Gr, as a highly conductive carbon, acts as an anchor for ZnO nanosheets and plays a substantial role in controlling the degree of dispersion of ZnO nanosheets onto indium-doped tin oxide (ITO) substrate to form Gr-ZnO nanocomposite. Atomic force microscopy (AFM) and field-emission scanning electron microscopy (FESEM) analysis of Gr-ZnO nanocomposite samples confirmed that the presence of ZnO nanosheets with a high degree of dispersity and crystallinity which is well linked to the thin layer of Gr nanoparticle on ITO substrate. The surface roughness of the films found increased to ~270 nm on Gr-ZnO as compared to Gr ~44 nm and ZnO ~3 nm. Further, the x-ray diffraction spectroscopy (XRD) analysis showed the result is in good agreement with Raman spectroscopy study. The cyclic voltammetry (CV) of Gr-ZnO nanocomposite revealed that the effect of electron-hole recombination process was increased and the presence of Gr in ZnO photoanode provides the fastest redox reaction and hence offers the fastest electron transfer in photoanode.


2010 ◽  
Vol 173 ◽  
pp. 102-105 ◽  
Author(s):  
Khairul Arifah Saharudin ◽  
Srimala Sreekantan

In this paper, anodization of Ti foil was carried out in ethylene glycol (EG) containing 5 wt% NH4F solution and 0 to 1.5 wt% of water at 50 V for 60 min. The pH of the bath was kept constant at ~pH7. The crystal structure was studied by X-Ray Diffraction (XRD) analysis, and the morphology was observed via field emission scanning electron microscopy (FESEM). TiO2 nanotube with aspect ratio of 100 was obtained in EG containing less than 1wt % water. The nanotubes wall was very smooth. Increasing the water content > 1wt % results in short nanotubes of approximately 6.2μm with aspect ratio of 62. As anodized, nanotubes were amorphous and annealed at 400 °C promote 100 % anatase phase. Photocatalytic activity of the nanotubes produced at different water content was also evaluated by the degradation of methyl orange and the detail of the observation was discussed thoroughly in this paper.


2014 ◽  
Vol 1073-1076 ◽  
pp. 743-746
Author(s):  
Xian Li ◽  
Jiang Wu ◽  
Xue Mei Qi ◽  
Chao En Li ◽  
Chong Zhang ◽  
...  

TiO2 hollow sphere was synthesized by hydrothermal method using Trifluoroacetic acid (TFA) and Ti (SO4)2 as raw materials. The photocatalytic properties of TiO2 hollow sphere were evaluated by the photocatalytic oxidization of elemental mercury (Hg0) in simulated flue gas. The as-prepared samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible diffuse reflectance spectroscopy and nitrogen sorption/desorption. The results show that only anatase phase for TiO2 the hollow sphere is obtained. The average diameter is about 800nm and the shell thickness was about 200nm. The sample prepared with TFA has better photocatalytic properties than P25.


2013 ◽  
Vol 873 ◽  
pp. 426-430
Author(s):  
Xian Wu Xiu ◽  
Li Xu ◽  
Cheng Qiang Zhang

Molybdenum-doped zinc oxide (MZO) films have been prepared by RF magnetron sputtering on glass substrates at room temperature. The structural, electrical and optical properties of the films vary with sputtering power from 15 W to 70 W are investigated. X-ray diffraction (XRD) analysis reveals that all the films are polycrystalline with the hexagonal structure and have a preferred orientation along thecaxis perpendicular to the substrate. The resistivity increases with the increase of the RF power. The lowest resistivity achieved is 5.4×10-3Ω cm at a RF power of 15 W with a Hall mobility of 11 cm2V-1s-1and a carrier concentration of 1.1×1019cm-3. The average transmittance drops from 85% to 81% in the visible range and the optical band gap decreases from 3.26 eV to 3.19 eV with the increase of the RF power.


Author(s):  
E. Romero Torres ◽  
M. Gutiérrez Arzaluz ◽  
V Mugica Alvarez ◽  
L. González Reyes ◽  
M. Torres Rodríguez ◽  
...  

The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) using a Au/TiO2 catalyst and ultraviolet (UV) light energy source (9 mW/cm2) discussed. Gold nanoparticles were synthesized by controlled urea reduction and deposited on titanium dioxide (TiO2) by the deposition-precipitation method. The average size of the nanoparticles was 6-8 nm. X-ray diffraction (XRD) characterization confirmed that TiO2 was present in the anatase phase, whereas the presence and particle size of gold were determined by transmission electron microscopy (TEM). The results of the degradation showed that the activity of TiO2 was improved when Au nanoparticles were present on the surface. The reactions were performed at atmospheric pressure and room temperature.


2020 ◽  
Vol 20 (3) ◽  
pp. 1447-1453 ◽  
Author(s):  
De-Shuai Zhen ◽  
Xiao-Hu Luo ◽  
De Yang ◽  
Hong-Tao Zou ◽  
Er-Hu Xiong ◽  
...  

In present work, a novel Nd@TiO2 Nanocomposite, synthesized successfully by a facile sol–gel method, reveals significant light-activated antibacterial activity. The X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) show the anatase phase and globular shape of Nd@TiO2. UV-vis diffuse reflectance spectroscopy and low temperature N2 adsorption (BET) indicate Nd0.02@TiO2 has the narrow band gap (3.0 eV) and a high specific surface area (121.1 m2·g-1). Furthermore, the prepared Nd@TiO2 exhibits unprecedented higher photocatalytic activity than P25 TiO2. In water, Nd@TiO2 has higher inactivation against Escherichia coli (E. coli) bacteria under simulated solar light irradiation 70 min than TiO2, and the highest antibacterial efficiency (91.5%) of E. coli was achieved on Nd0.02@TiO2.


2020 ◽  
Vol 20 (9) ◽  
pp. 5418-5425
Author(s):  
Dien-Trung Nguyen ◽  
Cam-Anh Ha ◽  
Tri Nguyen

In this work, titanium oxide catalysts were synthesized by the hydrothermal method from titanium isopropoxide (TTIP) as a precursor under acidic (Ti-A1 and Ti-A2), neutral (Ti-W) and alkaline (Ti-B) media. Characteristics of the catalysts were identified by various methods including X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller adsorption, UV-Vis diffuse reflectance spectroscopy, transmission electron microscopy, and Raman spectroscopy. The phase composition and PZC value of the obtained catalysts depended on the hydrothermal medium and the amount of TTIP: pure anatase and brookite phase formed at neutral and alkaline medium, respectively; whereas acidic medium favored the formation of anatase/rutile mixed phase and anatase phase decreased with the increasing amount of TTIP. The band gap energy of the synthesized catalysts was approximately 3.08–3.23 eV. Photocatalytic activity of synthesized catalysts was surveyed in the degradation of cinnamic acid (CA) solution at various pH in the region from 3.8 to 9.0 under UV irradiation. Photocatalytic oxidation was favorable in an acidic environment. At acidic pH values (3.8 and 5.0), the CA conversion was in the order of Ti-A2 ≥ Ti-A1 > Ti-P25 > Ti-W ≫ Ti-B, whereas it followed Ti-P25 > Ti-A1 > Ti-A2 ≈ Ti-W > Ti-B at pH 7.0 as well as pH 9.0.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2811
Author(s):  
Karla Čech Barabaszová ◽  
Sylva Holešová ◽  
Marianna Hundáková ◽  
Alena Kalendová

Materials made from low-density polyethylene (LDPE) in the form of packages or catheters are currently commonly applied medical devices. Antimicrobial LDPE nanocomposite materials with two types of nanofillers, zinc oxide/vermiculite (ZnO/V) and zinc oxide/vermiculite_chlorhexidine (ZnO/V_CH), were prepared by a melt-compounded procedure to enrich their controllable antimicrobial, microstructural, topographical and tribo-mechanical properties. X-ray diffraction (XRD) analysis and Fourier transform infrared spectroscopy (FTIR) revealed that the ZnO/V and ZnO/V_CH nanofillers and LDPE interacted well with each other. The influence of the nanofiller concentrations on the LDPE nanocomposite surface changes was studied through scanning electron microscopy (SEM), and the surface topology and roughness were studied using atomic force microscopy (AFM). The effect of the ZnO/V nanofiller on the increase in indentation hardness (HIT) was evaluated by AFM measurements and the Vickers microhardness (HV), which showed that as the concentration of the ZnO/V nanofiller increased, these values decreased. The ZnO/V and ZnO/V_CH nanofillers, regardless of the concentration in the LDPE matrix, slightly increased the average values of the friction coefficient (COF). The abrasion depths of the wear indicated that the LDPE_ZnO/V nanocomposite plates exhibited better wear resistance than LDPE_ZnO/V_CH. Higher HV and HIT microhardness values were measured for both nanofillers than the natural LDPE nanocomposite plate. Very positive antimicrobial activity against S. aureus and P. aeruginosa after 72 h was found for both nanofiller types.


Sign in / Sign up

Export Citation Format

Share Document