Photocatalysis of estrone in water and wastewater: Comparison between Au-TiO2 nanocomposite and TiO2, and degradation by-products

Sornalingam, Kireesan; McDonagh, Andrew M.; Zhou, John L.; Johir, Abu Hasan; Ahmed, Mohammad Boshir

doi:10.1016/j.scitotenv.2017.08.097

Cited by 65 publications

(42 citation statements)

References 59 publications

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“…Generally, the Fermi levels of the photo-deposited noble metals were lower than those in the TiO 2 conduction band [29], causing electrons to be efficiently transferred from the gold nanoparticles to the TiO 2 conduction band, thus preventing the recombination of the charge carriers and generating a more efficient photo-catalytic process [31]. However, as can be observed at higher percentages of Au, it is possible that a greater recombination process of the h + /epairs is present, as suggested by K. Sornalingam et al [32] at higher percentages of photo-deposited noble metals which can generate recombination processes by decreasing the photo-catalytic activity of the material [31,33]. In addition, at a high particle size, the active centers of TiO 2 can be blocked, thus decreasing the photo-catalytic activity.…”

Section: Catalytic Activity Measurementsmentioning

confidence: 95%

“…Generally, the Fermi levels of the photo-deposited noble metals were lower than those in the TiO2 conduction band [29], causing electrons to be efficiently transferred from the gold nanoparticles to the TiO2 conduction band, thus preventing the recombination of the charge carriers and generating a more efficient photo-catalytic process [31]. However, as can be observed at higher percentages of Au, it is possible that a greater recombination process of the h + /epairs is present, as suggested by K. Sornalingam et al [32] at higher percentages However, at short illumination times (40 min), it can be observed that the material with the best photo-catalytic behavior was 2Au-120, reaching a conversion higher than 60%, followed by the material 2Au-15, with a percentage lower than 50%. With respect to the materials 5Au-15 and 5Au-120, their behavior was lower still than the two previously described, with values lower than 40% and both very similar.…”

Section: Catalytic Activity Measurementsmentioning

confidence: 96%

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Differences in the Catalytic Behavior of Au-Metalized TiO2 Systems During Phenol Photo-Degradation and CO Oxidation

et al. 2019

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For this present work, a series of Au-metallized TiO2 catalysts were synthesized and characterized in order to compare their performance in two different catalytic environments: the phenol degradation that occurs during the liquid phase and in the CO oxidation phase, which proceeds the gas phase. The obtained materials were analyzed by different techniques such as XRF, SBET, XRD, TEM, XPS, and UV-Vis DRS. Although the metallization was not totally efficient in all cases, the amount of noble metal loaded depended strongly on the deposition time. Furthermore, the differences in the amount of loaded gold were important factors influencing the physicochemical properties of the catalysts, and consequently, their performances in the studied reactors. The addition of gold represented a considerable increase in the phenol conversion when compared with that of the TiO2, despite the small amount of noble metal loaded. However, this was not the case in the CO oxidation reaction. Beyond the differences in the phase where the reaction occurred, the loss of catalytic activity during the CO oxidation reaction was directly related to the sintering of the gold nanoparticles.

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Section: Catalytic Activity Measurementsmentioning

confidence: 95%

“…Generally, the Fermi levels of the photo-deposited noble metals were lower than those in the TiO2 conduction band [29], causing electrons to be efficiently transferred from the gold nanoparticles to the TiO2 conduction band, thus preventing the recombination of the charge carriers and generating a more efficient photo-catalytic process [31]. However, as can be observed at higher percentages of Au, it is possible that a greater recombination process of the h + /epairs is present, as suggested by K. Sornalingam et al [32] at higher percentages However, at short illumination times (40 min), it can be observed that the material with the best photo-catalytic behavior was 2Au-120, reaching a conversion higher than 60%, followed by the material 2Au-15, with a percentage lower than 50%. With respect to the materials 5Au-15 and 5Au-120, their behavior was lower still than the two previously described, with values lower than 40% and both very similar.…”

Section: Catalytic Activity Measurementsmentioning

confidence: 96%

Differences in the Catalytic Behavior of Au-Metalized TiO2 Systems During Phenol Photo-Degradation and CO Oxidation

et al. 2019

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“…R 2 ranges from 0.9323 to 0.9990, confirming the suitability of the pseudo-first order model to describe the kinetics of OII removal in the presence of ZnO-Ag (1.3%) and ZnO NPs, also applied by other authors to model the photocatalytic degradation of dyes and emerging contaminants. [16,27,[29][30][31]. Other works reported the photocatalytic degradation of OII using modified ZnO catalyst to improve kinetics.…”

Section: Influence Of Photocatalyst Concentration On Oii Removalmentioning

confidence: 99%

Enhanced Photocatalytic Activity of Semiconductor Nanocomposites Doped with Ag Nanoclusters Under UV and Visible Light

et al. 2019

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Emerging contaminants (ECs) represent a wide range of compounds, whose complete elimination from wastewaters by conventional methods is not always guaranteed, posing human and environmental risks. Advanced oxidation processes (AOPs), based on the generation of highly oxidizing species, lead to the degradation of these ECs. In this context, TiO2 and ZnO are the most widely used inorganic photocatalysts, mainly due to their low cost and wide availability. The addition of small amounts of nanoclusters may imply enhanced light absorption and an attenuation effect on the recombination rate of electron/hole pairs, resulting in improved photocatalytic activity. In this work, we propose the use of silver nanoclusters deposited on ZnO nanoparticles (ZnO–Ag), with a view to evaluating their catalytic activity under both ultraviolet A (UVA) and visible light, in order to reduce energetic requirements in prospective applications on a larger scale. The catalysts were produced and then characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and inductively coupled plasma-optical emission spectrometry (ICP-OES). As proof of concept of the capacity of photocatalysts doped with nanoclusters, experiments were carried out to remove the azo dye Orange II (OII). The results demonstrated the high photocatalytic efficiency achieved thanks to the incorporation of nanoclusters, especially evident in the experiments performed under white light.

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“…In this respect, some non-metallic organic compounds (e.g. urea [18][19][20] and polyaniline [21]), noble metals [22,23] and semiconductor composite [24] can be used to modify the surface of TiO 2 nanoparticles to enhance their photocatalytic activities, thereby effectively inhibiting the recombination of photoinduced carriers and broadening the absorption wavelength. Bonding interaction is an effective strategy for modifying catalyst materials.…”

Section: Introductionmentioning

confidence: 99%

Facile synthesis of C, N-TiO₂ nanorods via layered Ti 3 O 7 2 − -TMAH interlaminar bonding interaction and their enhanced catalytic performance

Wang

Hao

et al. 2020

Mater. Res. Express

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A green and efficient photocatalyst based on C and N co-doped titanium based nanorods (NRs) was prepared by facile hydrothermal synthesis and interlaminar bonding interaction between layered -Ti O 3 7 2 and tetramethylammonium hydroxide (TMAH). TMAH as one of quaternary ammoniumbased compounds was used as the doping source of C and N elements. The results showed that C and N co-doping did not affect the anatase crystal structure of TiO 2 NRs. C, N-TiO 2 NRs showed excellent photocatalytic activity for degrading methyl orange under simulated sunlight irradiation. In particular, the 20:1 TiO 2 NRs catalyst showed the best catalytic performance, showing efficient photocatalytic rate of 90%. The photocatalytic reaction kinetics of undoped and doped catalysts was also studied. In addition, reactive species (RSs) experiments showed that hydroxyl radical ( · OH), superoxide radical anions ( · O 2 −) and photogenerated holes (h + ) were major active species during the photocatalytic process. The mechanisms of the electrostatic attraction and potential photocatalytic degradation were proposed and discussed.

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Photocatalysis of estrone in water and wastewater: Comparison between Au-TiO2 nanocomposite and TiO2, and degradation by-products

Cited by 65 publications

References 59 publications

Differences in the Catalytic Behavior of Au-Metalized TiO2 Systems During Phenol Photo-Degradation and CO Oxidation

Differences in the Catalytic Behavior of Au-Metalized TiO2 Systems During Phenol Photo-Degradation and CO Oxidation

Enhanced Photocatalytic Activity of Semiconductor Nanocomposites Doped with Ag Nanoclusters Under UV and Visible Light

Facile synthesis of C, N-TiO₂ nanorods via layered Ti 3 O 7 2 − -TMAH interlaminar bonding interaction and their enhanced catalytic performance

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Photocatalysis of estrone in water and wastewater: Comparison between Au-TiO2 nanocomposite and TiO2, and degradation by-products

Cited by 65 publications

References 59 publications

Differences in the Catalytic Behavior of Au-Metalized TiO2 Systems During Phenol Photo-Degradation and CO Oxidation

Differences in the Catalytic Behavior of Au-Metalized TiO2 Systems During Phenol Photo-Degradation and CO Oxidation

Enhanced Photocatalytic Activity of Semiconductor Nanocomposites Doped with Ag Nanoclusters Under UV and Visible Light

Facile synthesis of C, N-TiO2 nanorods via layered Ti 3 O 7 2 − -TMAH interlaminar bonding interaction and their enhanced catalytic performance

Contact Info

Product

Resources

About

Facile synthesis of C, N-TiO₂ nanorods via layered Ti 3 O 7 2 − -TMAH interlaminar bonding interaction and their enhanced catalytic performance