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Photocatalytic removal of microcystin-LR by advanced WO3-based nanoparticles under simulated solar light.

Zhao C, Li D, Liu Y, Feng C, Zhang Z, Sugiura N, Yang Y - ScientificWorldJournal (2015)

Bottom Line: In the present study, Pt/WO3 exhibited the best performance for the photocatalytic degradation of MC-LR.The presence of metal cations (Cu2+ and Fe3+) improved the photocatalytic degradation of MC-LR.This study suggests that Pt/WO3 photocatalytic oxidation under solar light is a promising option for the purification of water containing MC-LR.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan ; School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China.

ABSTRACT
A series of advanced WO3-based photocatalysts including CuO/WO3, Pd/WO3, and Pt/WO3 were synthesized for the photocatalytic removal of microcystin-LR (MC-LR) under simulated solar light. In the present study, Pt/WO3 exhibited the best performance for the photocatalytic degradation of MC-LR. The MC-LR degradation can be described by pseudo-first-order kinetic model. Chloride ion (Cl-) with proper concentration could enhance the MC-LR degradation. The presence of metal cations (Cu2+ and Fe3+) improved the photocatalytic degradation of MC-LR. This study suggests that Pt/WO3 photocatalytic oxidation under solar light is a promising option for the purification of water containing MC-LR.

No MeSH data available.


Efficiency of photocatalytic degradation of MC-LR as a function of light intensity. (Experimental conditions: MC-LR concentration of 1 mg L−1 and Pt/WO3 concentration of 100 mg L−1.)
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fig6: Efficiency of photocatalytic degradation of MC-LR as a function of light intensity. (Experimental conditions: MC-LR concentration of 1 mg L−1 and Pt/WO3 concentration of 100 mg L−1.)

Mentions: The kinetic curves for the degradation of MC-LR by Pt/WO3 under various intensities of solar light irradiation are shown in Figure 6. The correlation coefficient (R2) values of linear regression in all the cases are greater than 0.99, which confirms the photocatalytic degradation of MC-LR by Pt/WO3 under simulated solar light well follows the pseudo-first-order kinetic equation. The corresponding kapp values of MC-LR degradation were 0.148, 0.196, and 0.241 min−1 under 0.2, 0.4, and 0.8 mW cm−2 solar light irradiation, respectively. At higher intensity of solar irradiation, more electron-hole pairs were expected to generate on photocatalyst surface, resulting in the enhancement of MC-LR degradation. According to Ohko et al. [29], if photocatalytic reaction proceeded under purely light-limited conditions, the degradation rate would depend on adsorbed photon numbers (light intensity) linearly. In this present study, a nonlinear relationship of photodegradation rate with light intensity was observed (figure was not shown) that seemingly implies the photocatalytic reaction proceeded under a light-rich condition. In that case, the surface adsorptive property of photocatalyst has a major influence on the photodegradation rate. Although MC-LR concentration showed a very slight decrease during 60 min dark adsorption (removal rate was less than 5%), a systematic study on the effects of initial MC-LR concentration should be carried out in the future research. That is helpful to understand clearly that the photodegradation proceeds under light-rich or light-limited condition. Since the average intensity of natural solar light is generally 0.8 mW cm−2, Pt/WO3 appears to be a promising photocatalyst for the degradation of MC-LR in practical water.


Photocatalytic removal of microcystin-LR by advanced WO3-based nanoparticles under simulated solar light.

Zhao C, Li D, Liu Y, Feng C, Zhang Z, Sugiura N, Yang Y - ScientificWorldJournal (2015)

Efficiency of photocatalytic degradation of MC-LR as a function of light intensity. (Experimental conditions: MC-LR concentration of 1 mg L−1 and Pt/WO3 concentration of 100 mg L−1.)
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4390111&req=5

fig6: Efficiency of photocatalytic degradation of MC-LR as a function of light intensity. (Experimental conditions: MC-LR concentration of 1 mg L−1 and Pt/WO3 concentration of 100 mg L−1.)
Mentions: The kinetic curves for the degradation of MC-LR by Pt/WO3 under various intensities of solar light irradiation are shown in Figure 6. The correlation coefficient (R2) values of linear regression in all the cases are greater than 0.99, which confirms the photocatalytic degradation of MC-LR by Pt/WO3 under simulated solar light well follows the pseudo-first-order kinetic equation. The corresponding kapp values of MC-LR degradation were 0.148, 0.196, and 0.241 min−1 under 0.2, 0.4, and 0.8 mW cm−2 solar light irradiation, respectively. At higher intensity of solar irradiation, more electron-hole pairs were expected to generate on photocatalyst surface, resulting in the enhancement of MC-LR degradation. According to Ohko et al. [29], if photocatalytic reaction proceeded under purely light-limited conditions, the degradation rate would depend on adsorbed photon numbers (light intensity) linearly. In this present study, a nonlinear relationship of photodegradation rate with light intensity was observed (figure was not shown) that seemingly implies the photocatalytic reaction proceeded under a light-rich condition. In that case, the surface adsorptive property of photocatalyst has a major influence on the photodegradation rate. Although MC-LR concentration showed a very slight decrease during 60 min dark adsorption (removal rate was less than 5%), a systematic study on the effects of initial MC-LR concentration should be carried out in the future research. That is helpful to understand clearly that the photodegradation proceeds under light-rich or light-limited condition. Since the average intensity of natural solar light is generally 0.8 mW cm−2, Pt/WO3 appears to be a promising photocatalyst for the degradation of MC-LR in practical water.

Bottom Line: In the present study, Pt/WO3 exhibited the best performance for the photocatalytic degradation of MC-LR.The presence of metal cations (Cu2+ and Fe3+) improved the photocatalytic degradation of MC-LR.This study suggests that Pt/WO3 photocatalytic oxidation under solar light is a promising option for the purification of water containing MC-LR.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan ; School of Water Resources and Environment, China University of Geosciences, Beijing 100083, China.

ABSTRACT
A series of advanced WO3-based photocatalysts including CuO/WO3, Pd/WO3, and Pt/WO3 were synthesized for the photocatalytic removal of microcystin-LR (MC-LR) under simulated solar light. In the present study, Pt/WO3 exhibited the best performance for the photocatalytic degradation of MC-LR. The MC-LR degradation can be described by pseudo-first-order kinetic model. Chloride ion (Cl-) with proper concentration could enhance the MC-LR degradation. The presence of metal cations (Cu2+ and Fe3+) improved the photocatalytic degradation of MC-LR. This study suggests that Pt/WO3 photocatalytic oxidation under solar light is a promising option for the purification of water containing MC-LR.

No MeSH data available.