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Photocatalytic decolorization of an aqueous bismarck brown R (4-[5-C2, 4-diamino-5- methylphenyl) diazenyl-2-methylphenyl] diazenyl-6-methylbenzene-1, 3-diamine dihydrochloride solution in a suspension of titanium dioxide (Degussa P25) was carried with the use of artificial light sources (UV- A). The disappearance of the original colored dye concen...
Context in source publication
Context 1
... results in Fig. 5 show the changes in the rate of decolorization of bismarck R brown on 1.75 g L -1 of titanium dioxide (Degussa P25) at 298.15 K with the initial dye concentrations (0.2 x 10 -4 -1.0 x 10 -4 M) at different times. The results indicate that decrease in dye concentration decreases the time of decolorization. 6 shows the photocatalytic ...
Citations
... All these excellent catalytic properties make it suitable for environmental applications. This oxide showed high catalytic activity in many applications such as environmental and industrial applications [6][7][8] . ...
... All these excellent catalytic properties make it suitable for environmental applications. This oxide showed high catalytic activity in many applications such as environmental and industrial applications [6][7][8] . ...
... All these excellent catalytic properties make it suitable for environmental applications. This oxide showed high catalytic activity in many applications such as environmental and industrial applications [6][7][8] . ...
... Table 3.15 shows effect of temperature on photocatalytic degradation process with constant mass of naked catalyst (0.10 g) and constant initial concentration of dye (5ppm) as seen in figure 3.26 and study the kinetic of reaction by calculating reaction rate constant from slope of plot. increasing of production of free radical [128] . That leads to increase the photocatalytic efficiency, which decreases the recombination process. ...
Photocatalytic degradation of leather industry wastewater (Malachite green dye) by using Niobium oxide
... Different attempts have been performed to improve the efficiency of TiO 2 depressing the recombination process of the photoelectron-hole pairs. Some of them include the modification of TiO 2 surface with other semiconductors to alter the charge-transfer properties between TiO 2 and the surrounding environment [22,23], sensitizing TiO 2 with colored inorganic or organic compounds improving its optical absorption in the visible light region [24][25][26][27][28], bulk modification by cation and anion doping [29][30][31][32][33][34][35][36][37][38], and fabrication of TiO 2 surface from polyhedral to produce hallow TiO 2 2 International Journal of Photoenergy [39,40]. TiO 2 nanoparticles are considered to be more active photocatalysts as compared with the bulk powder. ...
... Different attempts have been performed to improve the efficiency of TiO 2 depressing the recombination process of the photoelectron-hole pairs. Some of them include the modification of TiO 2 surface with other semiconductors to alter the charge-transfer properties between TiO 2 and the surrounding environment [22,23], sensitizing TiO 2 with colored inorganic or organic compounds improving its optical absorption in the visible light region [24][25][26][27][28], bulk modification by cation and anion doping [29][30][31][32][33][34][35][36][37][38], and fabrication of TiO 2 surface from polyhedral to produce hallow TiO 2 2 International Journal of Photoenergy [39,40]. TiO 2 nanoparticles are considered to be more active photocatalysts as compared with the bulk powder. ...
Titania modified nanoparticles have been prepared by the photodeposition method employing platinum particles on the commercially available titanium dioxide (Hombikat UV 100). The properties of the prepared photocatalysts were investigated by means of the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), and UVvisible diffuse spectrophotometry (UV-Vis). XRD was employed to determine the crystallographic phase and particle size of both
bare and platinised titanium dioxide. The results indicated that the particle size was decreased with the increasing of platinum loading. AFM analysis showed that one particle consists of about 9 to 11 crystals. UV-vis absorbance analysis showed that the absorption edge shifted to longer wavelength for 0.5% Pt loading compared with bare titanium dioxide.The photocatalytic activity of pure and Pt-loaded TiO2 was investigated employing the photocatalytic oxidation and dehydrogenation ofmethanol.The results of the photocatalytic activity indicate that the platinized titanium dioxide samples are always more active than the corresponding
bare TiO2 for both methanol oxidation and dehydrogenation processes. The loading with various platinum amounts resulted in a significant improvement of the photocatalytic activity of TiO2. This beneficial effect was attributed to an increased separation of the photogenerated electron-hole charge carriers.
... Different attempts have been performed to improve the efficiency of TiO 2 depressing the recombination process of the photoelectron-hole pairs. Some of them include the modification of TiO 2 surface with other semiconductors to alter the charge-transfer properties between TiO 2 and the surrounding environment [22,23], sensitizing TiO 2 with colored inorganic or organic compounds improving its optical absorption in the visible light region [24][25][26][27][28], bulk modification by cation and anion doping [29][30][31][32][33][34][35][36][37][38], and fabrication of TiO 2 surface from polyhedral to produce hallow TiO 2 2 International Journal of Photoenergy [39,40]. TiO 2 nanoparticles are considered to be more active photocatalysts as compared with the bulk powder. ...
Titania modified nanoparticles have been prepared by the photodeposition method employing platinum particles on the commercially available titanium dioxide (Hombikat UV 100). The properties of the prepared photocatalysts were investigated by means of the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-visible diffuse spectrophotometry (UV-Vis). XRD was employed to determine the crystallographic phase and particle size of both bare and platinised titanium dioxide. The results indicated that the particle size was decreased with the increasing of platinum loading. AFM analysis showed that one particle consists of about 9 to 11 crystals. UV-vis absorbance analysis showed that the absorption edge shifted to longer wavelength for 0.5% Pt loading compared with bare titanium dioxide. The photocatalytic activity of pure and Pt-loaded TiO2 was investigated employing the photocatalytic oxidation and dehydrogenation of methanol. The results of the photocatalytic activity indicate that the platinized titanium dioxide samples are always more active than the corresponding bare TiO2 for both methanol oxidation and dehydrogenation processes. The loading with various platinum amounts resulted in a significant improvement of the photocatalytic activity of TiO2. This beneficial effect was attributed to an increased separation of the photogenerated electron-hole charge carriers.
... These parameters make TiO 2 photocatalytic materials perfect candidate for photocatalytic processes. TiO 2 has been extensively studied and demonstrated to be suitable for numerous applications such as, destruction of microorganisms [3,4], inactivation of cancer cells [5,6], protection of the skin from the sun [7], photosplitting of water to produce hydrogen gas [8,9] and mineralization of toxic organic pollutants in water [10,11]. Even though TiO 2 is widely used as a semiconductor, it has some disadvantages like low surface area, fast recombination between photogenerated holes and electrons and wavelength maximum lies in the ultraviolet region. ...
... Ti VI -OH + -OH Ti VI -O -+ H 2 O, (pK 2 ) pH > pH zpc [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] At pH lower than pH zpc , the adsorbent surface is positively charged and then the adsorption of anions is favoured and as a consequence, the acidic water donates more protons than hydroxide groups. ...
... The maximum activity was achieved at zero point charge point. 11. The activation energy of the photocatalytic reaction in the existence of O 2 with the bare TiO 2 is equal to ∼ 22 kJ/mol, this value was reduced to ∼10 kJ/mol in platinum TiO 2 with the existence of O 2. This is related to the function of the metal as trap of electrons in addition to the activity of O 2 as electron scavenger. ...
This work consists of five parts. The first part is concerned with
the preparation of metalized TiO2 nanoparticales. Metalized TiO2 was
prepared by photodeposition of different percentage of platinum (Pt) or
gold (Au) on the surface of TiO2 Hombikat (UV 100) surface. The
properties of prepared photocatalysts were investigated by Atomic
absorption (A.A) analysis, Fourier transform infrared (FT-IR) analysis,
X-ray diffraction (XRD) analysis and Atomic force microscope (AFM)
analysis.
Scherrer equation and modified Scherrer equation were used to
calculate the mean crystallite sizes and crystallite sizes of bare and
metalized TiO2 via XRD data. The calculated mean crystallite sizes and
crystallite sizes of bare TiO2 decreased with the increasing of metal
percentage. The AFM images indicated that the shape of bare and
metalized TiO2 is spherical. The particle size was found ranged between 9
and 11 crystallite size.
The band gap energy values for bare TiO2, Pt(0.5)/TiO2 and
Au(0.5)/TiO2 were calculated after applying the Kubelka-Munk
transformation. The results show shifting ultra violet absorption to visible
light absorption (red shift) and band gap narrowing. The band gap of bare
TiO2 was reduced from 3.289 eV to 3.263 eV for Pt(0.5)/TiO2 and to
3.246 eV for Au(0.5)/TiO2 too.
The second part deals with the studying the effect of different
parameters on photocatalytic oxidation of methanol by using bare and
metal loaded on TiO2 surface. The parameters include: weight of catalyst,
types of metal, percentage of loaded metal, methanol concentration, pH
of solution and temperature. However the third part deals with the
studying the effect of the same parameters in the second part on
photocatalytic dehydrogenation of methanol by using bare and metal
loaded on TiO2 surface. The photocatalytic activities of bare and
metalized nanoparticles have been assessed by formaldehyde formation
and hydrogen evolution from aqueous methanol solution.
... Different attempts have been performed to improve the efficiency of TiO 2 depressing the recombination process of the photoelectron-hole pairs. Some of them include the modification of TiO 2 surface with other semiconductors to alter the charge-transfer properties between TiO 2 and the surrounding environment [22,23], sensitizing TiO 2 with colored inorganic or organic compounds improving its optical absorption in the visible light region [24][25][26][27][28], bulk modification by cation and anion doping [29][30][31][32][33][34][35][36][37][38], and fabrication of TiO 2 surface from polyhedral to produce hallow TiO 2 2 International Journal of Photoenergy [39,40]. TiO 2 nanoparticles are considered to be more active photocatalysts as compared with the bulk powder. ...
Nanosized titanium dioxide particles (Hombikat UV 100) doped with different percentages of platinum metal was prepared by
photodeposition method. Crystallite size and photocatalytic activity was characterized by X-ray diffraction and ultraviolet-visible light
spectroscopy, spontaneously. Spectrophotometer measurements have been used to determine the concentration of formed formaldehyde
following Nash method at a wavelength 412 nm. Doped titanium dioxide was found more active than naked one in the existence of oxygen
gas. However, naked titanium dioxide was found inactive in the existence of nitrogen gas and the suspension of aqueous methanol
solution was converted to grey colour indicating the consuming of titanium dioxide lattice oxygen. The effect of loading of platinum on
titanium dioxide was studied in the range 0.25-1 %. Platinized titanium dioxide with a loading of 0.5 wt % of platinum appeared to be the
most active photocatalyst in the selective partial dehydrogenation of methanol. Photocatalytic dehydrogenation was made over the temperature
range 278-298 K, using UVA radiation. Activation energies for formaldehyde formation were found identical on naked and platinized
Hombikat (23 ± 1 kJ mol-1). The identical activation energy for the photocatalytic dehydrogenation of aqueous methanol solution over
platinized and naked titanium dioxide in the presence of oxygen is believed to be associated with the transport of photoelectrons through
the catalyst to the adsorbed oxygen or metal on the surface of titanium dioxide.
... The treated wastewaters could be recycled in the same industry or reused in another industry or for agricultural fields. The efficiency of these methods of treatments is between 70 and 95% [19][20][21][22][23][24][25][26][27][28][29]. ...
The photocatalytic decolorization of industrial wastewater was investigated by using TiO2 and ZnO photocatalysts. Heterogeneous photocatalytic processes applied under natural weathering conditions, in the presence of solar radiation show a promising degradation capability. The complete removal of color could be achieved in a relatively short time of about 20 minutes, when ZnO was used and about 100 minutes when TiO2 was used under solar irradiation. However, in the presence of artificial UV-light, complete decolorization of textile industrial wastewater was obtained after less than one hour of irradiation when ZnO was used and in less than two hours, when TiO2 was used at the same temperature. The results indicate that the degree of photocatalytic decolorization of textile industrial wastewater was obviously affected by different parameters. These parameters include catalyst mass, type of catalyst, type of reactor, type of dye, dye concentration, and temperature. The procedure used in this research can be used as an efficient technology for solar photocatalytic decolorization of the colored wastewater discharged from the textile industry under the climatic conditions of most countries.
