Synergetic effect of CdS quantum dots and TiO2 nanofibers for photoelectrochemical hydrogen generation

Chaguetmi, Samiha; Mammeri, Fayna; Pasut, Mattia; Nowak, Sophie; Lecoq, Hélène; Decorse, Philippe; Costentin, Cyrille; Achour, S.; Ammar, Souad

doi:10.1007/s11051-013-2140-1

Cited by 25 publications

(11 citation statements)

References 40 publications

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“…The S 2p spectrum is formed by four peaks, which can be divided into two S chemically distinct environments. The two higher intensity peaks at 162.5 and 163.7 eV are the S 2p 3/2 and S 2p 1/2 spin-orbit components of S 2− , respectively, with a difference in binding energy of 1.2 eV and an intensity ratio of approximately 2:1, showing an excellent agreement with the S 2− signal previously reported for CdS nanoparticles [30]. The lower intensity peaks at higher binding energies of 169.4 4(a)).…”

Section: Chemical Surfacesupporting

confidence: 87%

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Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO₂nanotubes for photocatalytic hydrogen generation

et al. 2016

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Hydrogen fuels generated by water splitting using a photocatalyst and solar irradiation are currently gaining the strength to diversify the world energy matrix in a green way. CdS quantum dots have revealed a hydrogen generation improvement when added to TiO2 materials under visible-light irradiation. In the present paper, we investigated the performance of TiO2 nanotubes coupled with CdS quantum dots, by a molecular bifunctional linker, on photocatalytic hydrogen generation. TiO2 nanotubes were obtained by anodization of Ti foil, followed by annealing to crystallize the nanotubes into the anatase phase. Afterwards, the samples were sensitized with CdS quantum dots via an in situ hydrothermal route using 3-mercaptopropionic acid as the capping agent. This sensitization technique permits high loading and uniform distribution of CdS quantum dots onto TiO2 nanotubes. The XPS depth profile showed that CdS concentration remains almost unchanged (homogeneous), while the concentration relative to the sulfate anion decreases by more than 80% with respect to the initial value after ∼100 nm in depth. The presence of sulfate anions is due to the oxidation of sulfide and occurs in greater proportion in the material surface. This protection for air oxidation inside the nanotubular matrix seemingly protected the CdS for photocorrosion in sacrificial solution leading to good stability properties proved by long duration, stable photocurrent measurements. The effect of the size and the distribution of sizes of CdS quantum dots attached to TiO2 nanotubes on the photocatalytic hydrogen generation were investigated. The experimental results showed three different behaviors when the reaction time of CdS synthesis was increased in the sensitized samples, i.e. similar, deactivation and activation effects on the hydrogen production with regard to TiO2 nanotubes. The deactivation effect was related to two populations of sizes of CdS, where the population with a shorter band gap acts as a trap for the electrons photogenerated by the population with a larger band gap. Electron transfer from CdS quantum dots to TiO2 semiconductor nanotubes was proven by the results of UPS measurements combined with optical band gap measurements. This property facilitates an improvement of the visible-light hydrogen evolution rate from zero, for TiO2 nanotubes, to approximately 0.3 μmol cm(-2) h(-1) for TiO2 nanotubes sensitized with CdS quantum dots.

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Section: Chemical Surfacesupporting

confidence: 87%

“…The high-resolution XPS spectra of the Cd 3d core level for the NTs_TiO 2 + CdS 10mM _ 120 min sample (figure S6, supporting information), is characterized by Cd 3d 5/2 and Cd 3d 3/2 peaks centered at 405.9 and 412.6 eV, respectively, with a spin-orbit separation of 6.7 eV; these peaks can be assigned to the CdS nanoparticles [29,30].…”

Section: Chemical Surfacementioning

confidence: 99%

Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO₂nanotubes for photocatalytic hydrogen generation

et al. 2016

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“…Moreover, the low-cost fabrication, chemical stability, high specific surface area, excellent electron transfer behavior, large numbers of active reaction sites for chemical reactions, photosensitivity, and catalytic potential of TNAs make them valuable for nanotechnology applications that go from solar cells to biological sensors [1,3,4]. In that regard, CdS-decorated TNAs have been investigated in quantum dot (QD)-sensitized solar cells [1,[5][6][7], photoelectrochemical hydrogen production [8], and photocatalytic and photoelectrocatalytic degradation of contaminants in water [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Improving the contact properties of CdS-decorated TiO2 nanotube arrays using an electrochemical/thermal/chemical approach

Carrera-Crespo

Rincón

González

et al. 2016

J Solid State Electrochem

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Decoration of TiO 2 nanotube films (TiO 2 nanotube arrays (TNAs)) with CdS nanoparticles has been pursued for a broad range of applications that goes from solar cells to biological sensors. In most synthesis methods, the scale-up of devices has been challenging due to the poor contact at the chalcogenide/oxide interface. In this work, we validate the electrochemical/thermal/chemical route as a superior strategy to sensitize TNAs with CdS nanoparticles when compared with conventional methods. The process consisted of (i) electrodeposition of cadmium on TNAs to ensure strong bonding between TiO 2 and Cd precursor particles, (ii) air annealing of Cd-decorated TNAs to thermally oxidize cadmium to cadmium oxide, and (iii) total sulfurization of cadmium oxide to obtain CdS in an hexagonal phase matching that of TNAs. X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) analyses indicated the complete transformation of cadmium precursor particles into CdS and a good surface coverage of the internal/ external walls of TNAs. When compared to samples prepared by successive ionic layer adsorption and reaction (SILAR), electrochemical impedance spectroscopy data revealed the improvement of the electrical properties of the TNA matrix due to the sulfurization process and a lower contact resistance at the CdS/TNA interface. These improvements explain the superior photoelectrochemical response of CdS/TNA photoelectrodes obtained by the electrochemical/thermal/ chemical route.

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“…Chaguetmi et al have designed surface-modied CdS QDs impregnated into TiO 2 /Ti and reported excellent efficiency for PEC water splitting. 225 CdS-TiO 2 nanocomposite lms supported on the conductive sheet of Ti can be prepared using a three-step method. Surface-modied CdS QDs were prepared by a polyol method and were then incorporated into TiO 2 /Ti for efficient H 2 production.…”

Section: Cds-based Heterojunctionsmentioning

confidence: 99%

Recent developments and perspectives in CdS-based photocatalysts for water splitting

et al. 2020

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Synergetic effect of CdS quantum dots and TiO2 nanofibers for photoelectrochemical hydrogen generation

Cited by 25 publications

References 40 publications

Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO₂nanotubes for photocatalytic hydrogen generation

Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO₂nanotubes for photocatalytic hydrogen generation

Improving the contact properties of CdS-decorated TiO2 nanotube arrays using an electrochemical/thermal/chemical approach

Recent developments and perspectives in CdS-based photocatalysts for water splitting

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Synergetic effect of CdS quantum dots and TiO2 nanofibers for photoelectrochemical hydrogen generation

Cited by 25 publications

References 40 publications

Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO2nanotubes for photocatalytic hydrogen generation

Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO2nanotubes for photocatalytic hydrogen generation

Improving the contact properties of CdS-decorated TiO2 nanotube arrays using an electrochemical/thermal/chemical approach

Recent developments and perspectives in CdS-based photocatalysts for water splitting

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Product

Resources

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Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO₂nanotubes for photocatalytic hydrogen generation

Effects of the large distribution of CdS quantum dot sizes on the charge transfer interactions into TiO₂nanotubes for photocatalytic hydrogen generation