Impact of the absolute rutile fraction on TiO2 visible-light absorption and visible-light-promoted photocatalytic activity

Tobaldi, David Maria; Lajaunie, Luc; Rožman, Nejc; Caetano, Ana P.F.; Seabra, M.P.; Škapin, Andrijana Sever; Arenal, Raúl; Labrincha, J.A.

doi:10.1016/j.jphotochem.2019.111940

Cited by 34 publications

(40 citation statements)

References 93 publications

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“…When anatase and rutile TiO2 polymorphs are in form of heterojunction, a band alignment of around 0.4 eV exists, leading to enhanced visible light absorption [47] -this also happens in anatase-rutile nanopowders [48]. It has also been showed that a rutile fraction ≥ 2 wt% is able to shift the absorption edge of the mixture into the visible [14]. Furthermore, visible-light itself is able to trigger electron IFCT in CuO-TiO2 [31], that is Cu(II) ions may directly accept electrons from the valence band of TiO2, as described in the Optical analysis section.…”

Section: Mechanistic Aspects Of the Photocatalytic Hydrogen Generationmentioning

confidence: 99%

“…The whole powder pattern modelling (WPPM) [17], as implemented in the PM2K software package [18], was used for the microstructural analysis of the diffraction data. In this research work, we adopted the same modelling approach as that described in previous works of us, i.e., we assumed the crystalline domains to be spherical, and their diameter distributed according to a log-normal curve [14].…”

Section: Sample Characterisationmentioning

confidence: 99%

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Copper-Graphene-TiO2 Hybrid Materials for Photocatalytically Assisted H2 Generation

Tobaldi

Kočí²,

Edelmannová³

et al. 2020

Preprint

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Hydrogen, as energy carrier, is a zero-emission fuel. Being green and clean, it is considered to play an important role in energy and environmental issues. Photocatalytic water splitting is a process used to generate hydrogen from the dissociation of water. Titanium dioxide is still the archetype material for photocatalytic water splitting. However, because of the fast recombination of the photo-generated exciton, the yield of the reaction is typically low. In this work, we have modified the surface of titanium dioxide with copper and copper/graphene to sensitise it to visible light, and to increase the spatial charge carrier separation, thus extending the quantum yield of H2 production from methanol/water mixtures. Results showed that, in the analysed system, exists an optimum amount of copper plus graphene (i.e. 0.5 mol% copper plus 0.5 wt% graphene) to grant a two-fold increase in the photocatalytic hydrogen generation compared to that of bare titania. That system proved itself to be complex and dynamic. This was attributed to the increased spatial charge carrier separation exploited by graphene (under 365 and 405 nm irradiation), and to the continuous reduction of Cu(II) to Cu(I) due to IFCT that has proven to be an excellent visible-light sensitiser in the copper/graphene-titania system.Hybrid titania-copper-graphene materials could therefore be exploited in the field of light-to-energy applications.

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Section: Mechanistic Aspects Of the Photocatalytic Hydrogen Generationmentioning

confidence: 99%

Section: Sample Characterisationmentioning

confidence: 99%

Copper-Graphene-TiO2 Hybrid Materials for Photocatalytically Assisted H2 Generation

Tobaldi

Kočí²,

Edelmannová³

et al. 2020

Preprint

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“…We followed an aqueous sol-gel procedure for the synthesis of TiO 2 -based photocatalytic materials; details of the synthesis can be found in a paper previously described by the authors [30]. Briefly, aqueous sols were made by means of the controlled hydrolysis and peptisation of titanium(IV)isopropoxide [Ti-i-pr, Ti(OCH(CH 3 ) 2 ) 4 ] with Milli-Q water (18.2 MΩ.cm, H 2 O:Ti-i-pr=4:1) diluted in isopropyl alcohol IPA).…”

Section: Sample Preparationmentioning

confidence: 99%

“…The instrumental broadening was obtained from the refinement of LaB 6 standard (NIST SRM 660b) and included in all of the Rietveld refinements. The refinement strategy that we followed has been reported in previous a work [30]. XRPD was also used to gain microstructural information.…”

Section: Sample Characterisationmentioning

confidence: 99%

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Photocatalytic Aided Removal of Nitrogen Oxides and VOCs from Outdoor Environment: Graphene as a Highway for Electron Mobility in TiO2 Nanoparticles

Tobaldi

Dvoranová²,

Lajaunie³

et al. 2020

Preprint

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Outdoor and indoor air pollution is a global environmental concern in modern society. Although many policies and regulations on air quality have been promulgated worldwide over the past decades, airborne pollution still negatively affects health and therefore the life-style of human beings. One of the strategies to challenge this problem might be reducing the amount of airborne pollutant by mineralising them via photoinduced reactions. Photocatalytic oxidation of gaseous pollutants via titanium dioxide is one of the most investigated solar photochemical reactions. In this research work, by means of a green sol-gel procedure, we have coupled titania to graphene (0.5 and 1.0 wt%) aiming to increase the solar photocatalytic activity of the produced hybrid materials. The photocatalytic reactions were assessed by monitoring the removal of nitrogen oxides and two different volatile organic compounds (benzene and isopropanol). Photocatalytic mechanism was investigated by means of EPR spin trapping experiments.Our results highlight the exceptional characteristics of the TiO2/graphene hybrid material (1.0 wt% graphene), and its suitability for multi-purpose applications in the field of environmental remediation. Compared to unmodified titania, the hybrid material with 1.0 wt% graphene shows a clear enhancement in the photocatalytic removal of those hazardous pollutants – corresponding to more than twice the photocatalytic degradation rate. In addition, the same material is highly stable and shows fully recyclability over repeated tests. Hybrid titania-graphene materials could thus be exploited to grant a safer outdoor and indoor environments, having a beneficial impact on public health and thus on the quality of our lives.

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Effect of TiO2 sol on the conversion efficiency of TiO2 based dye-sensitized solar cell

Toe

Pung

Yaacob

et al. 2020

J Sol-Gel Sci Technol

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Impact of the absolute rutile fraction on TiO2 visible-light absorption and visible-light-promoted photocatalytic activity

Cited by 34 publications

References 93 publications

Copper-Graphene-TiO2 Hybrid Materials for Photocatalytically Assisted H2 Generation

Copper-Graphene-TiO2 Hybrid Materials for Photocatalytically Assisted H2 Generation

Photocatalytic Aided Removal of Nitrogen Oxides and VOCs from Outdoor Environment: Graphene as a Highway for Electron Mobility in TiO2 Nanoparticles

Effect of TiO2 sol on the conversion efficiency of TiO2 based dye-sensitized solar cell

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