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Enhanced photoelectrochemical and photocatalytic activity of WO3-surface modified TiO2 thin film.

Qamar M, Drmosh Q, Ahmed MI, Qamaruddin M, Yamani ZH - Nanoscale Res Lett (2015)

Bottom Line: An enhancement in the photocurrent was observed when the TiO2 surface was modified WO3 nanoparticles.Photocatalytic activity of TiO2 and WO3-modified TiO2 for the decolorization of methyl orange was tested.Graphical abstractWO3-surface modified TiO2 film showing better photocatalytic and photoelectrocatalytic activity.

View Article: PubMed Central - PubMed

Affiliation: Center of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals (KFUPM), Box 498, Dhahran, 31261 Saudi Arabia.

ABSTRACT
Development of nanostructured photocatalysts for harnessing solar energy in energy-efficient and environmentally benign way remains an important area of research. Pure and WO3-surface modified thin films of TiO2 were prepared by magnetron sputtering on indium tin oxide glass, and photoelectrochemical and photocatalytic activities of these films were studied. TiO2 particles were <50 nm, while deposited WO3 particles were <20 nm in size. An enhancement in the photocurrent was observed when the TiO2 surface was modified WO3 nanoparticles. Effect of potential, WO3 amount, and radiations of different wavelengths on the photoelectrochemical activity of TiO2 electrodes was investigated. Photocatalytic activity of TiO2 and WO3-modified TiO2 for the decolorization of methyl orange was tested. Graphical abstractWO3-surface modified TiO2 film showing better photocatalytic and photoelectrocatalytic activity.

No MeSH data available.


Related in: MedlinePlus

Action spectra of photocurrent in presence of TiO2and WO3/TiO2(deposition time = 5 min) thin film electrodes.
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Fig3: Action spectra of photocurrent in presence of TiO2and WO3/TiO2(deposition time = 5 min) thin film electrodes.

Mentions: Photocurrent action spectra or effect of wavelength on the photocurrent of pure and WO3-modified TiO2 electrodes (deposition time = 5 min) was measured at a constant applied anodic potential (0.9 V). Furthermore, three scans were performed at each wavelength and results together with error bars are presented in Figure 3. Since the linear relationship between light intensity and photocurrent can interfere with the effect of wavelengths and lead to an elusive conclusion, the intensity of incident light was kept constant, with the help of neutral density filters equipped with the xenon light source, at different wavelengths. Both the films showed maximum photocurrent at 320 nm and found to decrease continuously with the increase in wavelength (or decrease in photonic energy) up to 460 nm. However, the photocurrent of bare TiO2 was significantly less than that of WO3-modified TiO2 at any wavelength studied. By keeping in mind that the illumination of catalyst’s surface with high-energy photons may induce some changes by creating surface states [26], the direction of wavelength scanning was followed from higher to lower, i.e., from low-energy photons to high-energy photons in order to minimize any such kind of effect. The trend of photocurrent flow as a function of wavelengths agreed fairly well with absorption spectra of samples (Figure 3). Furthermore, since the specimens may show a certain degree of current drift over time scales of 5 to 10 min, ambiguity between photocurrents under illumination and dark current is created. Photocurrents (under illumination and dark current) were measured in a single experiment by turning the light on and off after every 25 s for more than 8 min at a constant applied voltage 0.9 V, and obtained results are presented in Figure 4. The photocurrent generated instantaneously upon illumination and reached a steady state while no current was observed under dark, even at high applied potential (0.9 V). It could be seen from the figure that both the electrodes possessed similar and reasonably good stability under studied experimental conditions and WO3-modified TiO2 electrode showed better photocurrent.Figure 3


Enhanced photoelectrochemical and photocatalytic activity of WO3-surface modified TiO2 thin film.

Qamar M, Drmosh Q, Ahmed MI, Qamaruddin M, Yamani ZH - Nanoscale Res Lett (2015)

Action spectra of photocurrent in presence of TiO2and WO3/TiO2(deposition time = 5 min) thin film electrodes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385024&req=5

Fig3: Action spectra of photocurrent in presence of TiO2and WO3/TiO2(deposition time = 5 min) thin film electrodes.
Mentions: Photocurrent action spectra or effect of wavelength on the photocurrent of pure and WO3-modified TiO2 electrodes (deposition time = 5 min) was measured at a constant applied anodic potential (0.9 V). Furthermore, three scans were performed at each wavelength and results together with error bars are presented in Figure 3. Since the linear relationship between light intensity and photocurrent can interfere with the effect of wavelengths and lead to an elusive conclusion, the intensity of incident light was kept constant, with the help of neutral density filters equipped with the xenon light source, at different wavelengths. Both the films showed maximum photocurrent at 320 nm and found to decrease continuously with the increase in wavelength (or decrease in photonic energy) up to 460 nm. However, the photocurrent of bare TiO2 was significantly less than that of WO3-modified TiO2 at any wavelength studied. By keeping in mind that the illumination of catalyst’s surface with high-energy photons may induce some changes by creating surface states [26], the direction of wavelength scanning was followed from higher to lower, i.e., from low-energy photons to high-energy photons in order to minimize any such kind of effect. The trend of photocurrent flow as a function of wavelengths agreed fairly well with absorption spectra of samples (Figure 3). Furthermore, since the specimens may show a certain degree of current drift over time scales of 5 to 10 min, ambiguity between photocurrents under illumination and dark current is created. Photocurrents (under illumination and dark current) were measured in a single experiment by turning the light on and off after every 25 s for more than 8 min at a constant applied voltage 0.9 V, and obtained results are presented in Figure 4. The photocurrent generated instantaneously upon illumination and reached a steady state while no current was observed under dark, even at high applied potential (0.9 V). It could be seen from the figure that both the electrodes possessed similar and reasonably good stability under studied experimental conditions and WO3-modified TiO2 electrode showed better photocurrent.Figure 3

Bottom Line: An enhancement in the photocurrent was observed when the TiO2 surface was modified WO3 nanoparticles.Photocatalytic activity of TiO2 and WO3-modified TiO2 for the decolorization of methyl orange was tested.Graphical abstractWO3-surface modified TiO2 film showing better photocatalytic and photoelectrocatalytic activity.

View Article: PubMed Central - PubMed

Affiliation: Center of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals (KFUPM), Box 498, Dhahran, 31261 Saudi Arabia.

ABSTRACT
Development of nanostructured photocatalysts for harnessing solar energy in energy-efficient and environmentally benign way remains an important area of research. Pure and WO3-surface modified thin films of TiO2 were prepared by magnetron sputtering on indium tin oxide glass, and photoelectrochemical and photocatalytic activities of these films were studied. TiO2 particles were <50 nm, while deposited WO3 particles were <20 nm in size. An enhancement in the photocurrent was observed when the TiO2 surface was modified WO3 nanoparticles. Effect of potential, WO3 amount, and radiations of different wavelengths on the photoelectrochemical activity of TiO2 electrodes was investigated. Photocatalytic activity of TiO2 and WO3-modified TiO2 for the decolorization of methyl orange was tested. Graphical abstractWO3-surface modified TiO2 film showing better photocatalytic and photoelectrocatalytic activity.

No MeSH data available.


Related in: MedlinePlus