Sustained water cleavage by visible light

Borgarello, Enrico; Kiwi, J.; Pelizzetti, Ezio; Visca, M.; Gräetzel, Michael

doi:10.1021/ja00411a010

Cited by 291 publications

(105 citation statements)

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“…These reactive oxygen species can drive various chemical reactions. The photoelectrochemical reactions of titanium dioxide particles have been studied as several phototechnologies, such as solar energy conversion to chemical energy, photosynthesis and photocatalysis (Inoue et al, 1979;Borgarello et al, 1981;Fujihira et al, 1981;Kodama & Yagi, 1990;Peral et al, 1990).…”

mentioning

confidence: 99%

Photokilling of T-24 human bladder cancer cells with titanium dioxide

Kubota

Shuin²,

Kawasaki³

et al. 1994

Br J Cancer

195

105

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A photoexcited titanium dioxide surface has a strong ability to decompose water into hydrogen and oxygen. We have studied this effect in order to use it to kill cancer cells in vitro and in vivo. A distinct cell killing effect was observed on cultured T-24 human bladder cancer cells treated with titanium dioxide particles and 300-400 nm UV light irradiation. Titanium dioxide plus UV light also dramatically suppressed the tumour growth of T-24 cells that were implanted in nude mice. Cells cultured on the titanium dioxide electrode were also killed under UV irradiation when the electrode was anodically polarised, suggesting that photogenerated holes are involved in the cell killing. The cell killing effect caused by titanium dioxide particles plus UV light irradiation was significantly hampered in the presence of L-cysteine and catalase, scavengers of hydroxyl radicals and hydrogen peroxide respectively. Transmission electron microscopic observations showed the titanium dioxide particles to be distributed on the cell surface and inside the cells. These results suggest that titanium dioxide particles under UV light irradiation produced photogenerated holes on the surface yielding hydroxyl radicals and hydrogen peroxide inside or outside the cells and the cells were then killed by the action of these highly oxidising molecules. The possible application of photoexcited titanium dioxide particles to cancer treatment as a new anti-cancer modality is discussed. Images Figure 6

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mentioning

confidence: 99%

Photokilling of T-24 human bladder cancer cells with titanium dioxide

Kubota

Shuin²,

Kawasaki³

et al. 1994

Br J Cancer

195

105

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“…The average crystallite size of the TiO 2 thin films with Fe 3þ -doped concentrations (5 wt.% and 10 wt.%) was calcined at 450 C determined by the Scherrer's equation. 16 The crystallite size of TiO 2 decreases from 36 nm to 8 nm when the Fe dopant concentration increases from 5 wt.% to 10 wt.%. 17 The full width half maximum values with peak positions and relative intensities of the un-doped and doped TiO 2 films are listed in Table 2.…”

Section: Characterization Of Tio 2 Filmmentioning

confidence: 97%

Effect of iron doping on structural and optical properties of TiO₂thin film by sol–gel routed spin coating technique

Lourduraj¹,

Williams²

2017

J. Adv. Dielect.

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Thin films of iron (Fe)-doped titanium dioxide (Fe:TiO 2 Þ were prepared by sol-gel spin coating technique and further calcined at 450 C. The structural and optical properties of Fe-doped TiO 2 thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis) and atomic force microscopic (AFM) techniques. The XRD results confirm the nanostructured TiO 2 thin films having crystalline nature with anatase phase. The characterization results show that the calcined thin films having high crystallinity and the effect of iron substitution lead to decreased crystallinity. The SEM investigations of Fe-doped TiO 2 films also gave evidence that the films were continuous spherical shaped particles with a nanometric range of grain size and film was porous in nature. AFM analysis establishes that the uniformity of the TiO 2 thin film with average roughness values. The optical measurements show that the films having high transparency in the visible region and the optical band gap energy of Fe-doped TiO 2 film with iron (Fe) decrease with increase in iron content. These important requirements for the Fe:TiO 2 films are to be used as window layers in solar cells.

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“…Moreover, it is possible that inefficient electron injection from the sacrificial agent to the HOMO of the dyes leads to lower photocatalytic efficiency. Although the efficiency of dye-sensitized H 2 evolution is currently lower than that of ruthenium-based dyes [34,35] or a non-sensitized photocatalyst, [12,50] the optimal design of organic dye molecules to harvest a wide range of the solar light spectrum will achieve efficient water splitting.…”

Section: Photocatalytic Performancementioning

confidence: 99%

“…Because the electron-transfer step resembles that in DSSCs, dye-sensitized semiconductors could also function as photocatalysts for water splitting under visible-light irradiation. [12] Although ruthenium dyes give the best performance in photocatalysis, [34,35] researchers have gradually switched to low cost, metal-free, organic dyes with high design flexibility of the molecules. To Two organic donor-acceptor-p-acceptor (D-A-p-A) sensitizers (AQ and AP), containing quinoxaline/pyrido [3,4-b]pyrazine as the auxiliary acceptor, have been.…”

Section: Introductionmentioning

confidence: 99%

New Organic Donor–Acceptor–π–Acceptor Sensitizers for Efficient Dye‐Sensitized Solar Cells and Photocatalytic Hydrogen Evolution under Visible‐Light Irradiation

Cui

Wang

et al. 2014

ChemSusChem

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Two organic donor-acceptor-π-acceptor (D-A-π-A) sensitizers (AQ and AP), containing quinoxaline/pyrido[3,4-b]pyrazine as the auxiliary acceptor, have been. Through fine-tuning of the auxiliary acceptor, a higher designed and synthesized photoelectric conversion efficiency of 6.02% for the AQ-based dye-sensitized solar cells under standard global AM1.5 solar conditions was achieved. Also, it was found that AQ-Pt/TiO2 photocatalysts displayed a better rate of H2 evolution under visible-light irradiation (420 nm<λ<780 nm) because of the stability of the oxidized states and the lower rates of electron recombination. Importantly, sensitizers AQ and AP-Pt/TiO2 showed strong photocatalytic activity during continuous light soaking for 10 h with methanol as the sacrificial electron donor. Additionally, the processes of their intermolecular electron transfer were further investigated theoretically by using time-dependent DFT. The calculated results indicate that the auxiliary acceptor plays the role of an electron trap and results in broad spectral responses.

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Sustained water cleavage by visible light

Cited by 291 publications

References 0 publications

Photokilling of T-24 human bladder cancer cells with titanium dioxide

Photokilling of T-24 human bladder cancer cells with titanium dioxide

Effect of iron doping on structural and optical properties of TiO₂thin film by sol–gel routed spin coating technique

New Organic Donor–Acceptor–π–Acceptor Sensitizers for Efficient Dye‐Sensitized Solar Cells and Photocatalytic Hydrogen Evolution under Visible‐Light Irradiation

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Sustained water cleavage by visible light

Cited by 291 publications

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Photokilling of T-24 human bladder cancer cells with titanium dioxide

Photokilling of T-24 human bladder cancer cells with titanium dioxide

Effect of iron doping on structural and optical properties of TiO2thin film by sol–gel routed spin coating technique

New Organic Donor–Acceptor–π–Acceptor Sensitizers for Efficient Dye‐Sensitized Solar Cells and Photocatalytic Hydrogen Evolution under Visible‐Light Irradiation

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Effect of iron doping on structural and optical properties of TiO₂thin film by sol–gel routed spin coating technique