Photolysis of water with supported noble metal clusters, the fate of oxygen in titania based water cleavage systems

Yesodharan, E.P.; Yesodharan, Suguna; Grätzel, Michaël

doi:10.1016/0165-1633(84)90035-2

Cited by 33 publications

(16 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since it is observed that considerable photocatalytic reaction occurred in the alkaline range as well, it is inferred that the reaction occurs not only on the surface but also in its close vicinity. Heterogeneously initiated homogeneous reactions have been observed in earlier studies also 18 . Further, alkaline pH favours the formation of more OH radicals due to the presence of large quantity of OHions in the alkaline medium, which can enhance the photocatalytic degradation.…”

Section: Effect Of Phsupporting

confidence: 60%

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO₂ Immobilised on Ceramic Tiles

Palanisamy¹,

Kavitha²

2010

Journal of Chemistry

View full text Add to dashboard Cite

The photocatalytic activity of TiO 2 immobilized on different supports; cement and ceramic tile, was studied to decolorize two commercial dyes. The catalyst was immobilised by two different techniques, namely, slurry method on ceramic tile and powder scattering on cement. The degradation of the dyes was carried out using UV and solar irradiation. The comparative efficiency of the catalyst immobilised on two different supports was determined. The photodegradation process was monitored by UV-Vis spectrophotometer. The catalyst immobilised on ceramic tile was found to be better than the catalyst immobilised on cement. Experimental results showed that both illumination and the catalyst were necessary for the degradation of the dyes and UV irradiation is more efficient compared to solar irradiation.

show abstract

Section: Effect Of Phsupporting

confidence: 60%

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO₂ Immobilised on Ceramic Tiles

Palanisamy¹,

Kavitha²

2010

Journal of Chemistry

View full text Add to dashboard Cite

show abstract

“…21 Graetzel speculated that on anatase reaction 3 proceeds in two one-electron steps with free superoxide radicals as intermediates (eqs 4/5). 9 Using electrochemical data, Augustinsky could show that for anatase TiO 2 (but not for rutile) two-electron oxidation of water (eq 6) does * To whom correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

“…If the band gap of the material is large enough (at least 2.4 eV), 6,7 irradiation of an aqueous catalyst dispersion can lead to H 2 and O 2 . However, for many metal oxides, including the anatase form of TiO 2 , [8][9][10][11] several titanates, and niobates (KCa 2 …”

Section: Introductionmentioning

confidence: 99%

“…Grätzel and later Arakawa's group [15][16][17] have investigated this phenomenon in greater detail. For anatase powders with or without Rhor Pt-cocatalysts, it was found that no O 2 is evolved and that H 2 evolution ceases after 28 h. [9][10][11][18][19][20] Using a redox active dye it was shown that peroxide/superoxide species were produced during the reaction (eq 2), and that these species adsorbed to the catalyst surface and deactivated it over time. However, the binding geometry of the peroxides could not be determined.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Niobate Nanosheets as Catalysts for Photochemical Water Splitting into Hydrogen and Hydrogen Peroxide

2008

View full text Add to dashboard Cite

Tetrabutylammonium-stabilized Ca 2 Nb 3 O 10 nanosheets catalyze photochemical splitting of water into hydrogen and hydrogen peroxide under UV irradiation. The peroxide forms on the surface of the catalyst and adsorbs to it, fully deactivating the catalyst after 48 h of irradiation. For the Pt-modified niobate, complete deactivation occurs within 24 h due to higher H 2 evolution rate with this system. The peroxide was identified via Raman and IR spectroscopy. In vibrational spectra, the irradiated niobate exhibits bands at 580, 778, and 940 cm -1 , which suggest that the peroxide is present as a side-on ligand coordinated to the Nb 5+ ions on the nanosheet surface. The same species can be formed by treating the nanosheets with 30% aqueous H 2 O 2 . If the catalyst is irradiated in H 2 18 O, the bands shift to lower energy, indicating that the peroxide species is formed from water. Room-temperature storage of the nanosheets in H 2 18 O also leads to isotopic exchange of all Nb-O atoms over the course of 24 h. Peroxide amounts measured by titration of the catalyst with o-tolidine after 6, 12, and 24 h of irradiation form in a 1:1 stoichiometry with hydrogen. Infrared data shows that the peroxide is partially desorbed by evacuating the catalyst and by purging with argon gas. Under catalytic conditions, this treatment restores up to 60% of the original activity. For the H 2 O 2 -treated catalyst, near quantitative H 2 O 2 desorption occurs within 20 min at 450°C. Separate irradiation experiments of the catalyst in the presence of air reveal that H 2 evolution is diminished and that O 2 uptake occurs from the atmosphere. Most of the hydrogen peroxide formed under these conditions is subsequently detected in the supernatant and only small amounts on the catalyst. NMR spectra show that the tetrabutylammonium cations are decomposed. These findings suggest that there are two distinct pathways for peroxide formation, one involving one-electron reduction of O 2 and one involving two-electron reduction of water (in the absence of O 2 ).

show abstract

“…From this observation, they postulated that some forms of dissociatively adsorbed H 2 O 2 are present on the catalyst surface, which prevents further reactions from occurring (2H 2 O → H 2 + H 2 O 2 , although a more endothermic reaction than that to H 2 and O 2 ). This idea has initially been presented by Grätzel et al 5 among others. It is however possible that some hydrocarbon contaminants on the surface of these semiconductor catalysts are responsible for this noncatalytic hydrogen evolution.…”

mentioning

confidence: 97%

The elusive photocatalytic water splitting reaction using sunlight on suspended nanoparticles: is there a way forward?

Idriss

2020

Catal. Sci. Technol.

View full text Add to dashboard Cite

show abstract

Photolysis of water with supported noble metal clusters, the fate of oxygen in titania based water cleavage systems

Cited by 33 publications

References 20 publications

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO₂ Immobilised on Ceramic Tiles

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO₂ Immobilised on Ceramic Tiles

Niobate Nanosheets as Catalysts for Photochemical Water Splitting into Hydrogen and Hydrogen Peroxide

The elusive photocatalytic water splitting reaction using sunlight on suspended nanoparticles: is there a way forward?

Contact Info

Product

Resources

About

Photolysis of water with supported noble metal clusters, the fate of oxygen in titania based water cleavage systems

Cited by 33 publications

References 20 publications

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO2 Immobilised on Ceramic Tiles

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO2 Immobilised on Ceramic Tiles

Niobate Nanosheets as Catalysts for Photochemical Water Splitting into Hydrogen and Hydrogen Peroxide

The elusive photocatalytic water splitting reaction using sunlight on suspended nanoparticles: is there a way forward?

Contact Info

Product

Resources

About

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO₂ Immobilised on Ceramic Tiles

Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO₂ Immobilised on Ceramic Tiles