Properties and photochemistry of valence-induced-Ti<sup>3+</sup>enriched (Nb,N)-codoped anatase TiO<sub>2</sub>semiconductors

Folli, Andrea; Bloh, Jonathan Z.; Lecaplain, Anaïs; Walker, Rebecca; Macphee, Donald E.

doi:10.1039/c4cp05521g

Cited by 24 publications

(16 citation statements)

References 27 publications

(81 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These spectral changes match what has been previously reported for similar Ndoped TiO 2 samples. 37,40,42,43,46 The EPR spectrum recorded under light irradiation is also reported in the SI at higher resolution with overall simulation; deconvolution of the N1, N2…”

Section: Photochemical Responsementioning

confidence: 98%

Improving the Selectivity of Photocatalytic NO_x Abatement through Improved O₂ Reduction Pathways Using Ti_0.909W_0.091O₂N_x Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

et al. 2018

Self Cite

View full text Add to dashboard Cite

In this paper we provide detailed insight into the electronic-crystallographic-structural relationship for Ti 0.909 W 0.091 O 2 N x semiconductor nanoparticles, explaining the mutual electronic and magnetic influence of the photo-induced, stable N-and W-based paramagnetic centres, their involvement in the photo-induced charge carriers trapping and their role in improving the nitrate selectivity of the photocatalytic oxidation of NOx to nitrates. In particular, reduced tungsten species in various crystallographic environments within the anatase host lattice were observed to play a fundamental role in storing and stabilising photo-generated electrons. Here we show how these reduced centres can catalyse multi-electron transfer events without the need for rare and expensive platinum group metals (PGMs). This allows for a versatile and elegant design of redox potentials. As a result, electron transfer processes that are kinetically inaccessible with metal oxides such as TiO 2 can now be accessed, enabling dramatic improvements in reaction selectivity. The photocatalytic abatement of NOx towards non-toxic products is exemplified here and is shown to pivot on multiple routes for molecular oxygen reduction. The same rationale can furthermore be applied to other photocatalytic processes. The observations described in this work could open new exciting avenues in semiconductor photocatalysis for environmental remediation technologies, where the optimisation of molecular oxygen reduction, together with the pollutant species to be oxidised, becomes a central element of the catalyst design, without relying on the use of rare and expensive PGMs.

show abstract

Section: Photochemical Responsementioning

confidence: 98%

Improving the Selectivity of Photocatalytic NO_x Abatement through Improved O₂ Reduction Pathways Using Ti_0.909W_0.091O₂N_x Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…The higher loading of dye and greater interaction between dye and TiO 2 , potentially enhance electron injection which along with reduced electron recombination leads to better photovoltaic performances. Again, from Taucs’ plot (Figure b) it was observed that the lower the particle size of the material, higher is the band‐gap energy of the material and materials with higher band gap energy have better photovoltaic profiles ,. Interestingly, TNP‐II, with the highest band gap, exhibited the best energy conversion efficiency.…”

Section: Resultsmentioning

confidence: 95%

“…Again, from Taucs' plot ( Figure 2b) it was observed that the lower the particle size of the material, higher is the band-gap energy of the material and materials with higher band gap energy have better photovoltaic profiles. [53,54] Interestingly, TNP-II, with the highest band gap, exhibited the best energy conversion efficiency.…”

Section: Mott -Schottky Plot and Flat Band Potentialmentioning

confidence: 99%

Effect of Particle Size on the Performance of TiO₂ Based Dye‐Sensitized Solar Cells

et al. 2018

View full text Add to dashboard Cite

The performance of TiO2 based dye‐sensitized solar cells (DSSCs) is largely influenced by the size of the TiO2 particles. In this work, different‐sized TiO2 nanoparticles have been synthesized by a facile sol–gel technique using polyethylene glycol (PEG) as capping agent and its performance as the photoanode of DSSC with N719 sensitizer dye is investigated. Particle nature and dimension of TiO2 nanoparticles were studied through XRD, FTIR, SEM and dynamic light scattering (DLS) analyses, whereas thermal stability was investigated through TGA in the temperature range of 30–600 °C 30–600 °C. The DSSC assembled with photoanode consisted of smallest size TiO2 nanoparticles obtained using 3 mM PEG (TNP‐II) exhibited solar‐to‐electrical energy conversion efficiency of 2.5%, under illumination of 100 mWcm−2, which was an extensive improvement compared to the device based on un‐capped, TiO2 nanoparticles based cell (TNP) (1.0%). The enhancement in efficiency resulting from the reduction of particles size of TiO2 is attributed to enlarged band‐gap, increased specific surface area & surface to volume ratio of the photoanode, greater dye loading and more interactions between anchoring groups of the dye and surface of TiO2. EIS measurements revealed that TNP‐II photoanode–based cells exhibited faster electron transport, increased electron lifetime, higher charge collection efficiency and less recombination leading to better photovoltaic output. The work shows that developed TNP‐II nanoparticles have good potential for application in photoenergy conversion devices.

show abstract

“…where C SC is the capacitance of the space charge region, ϵ 0 is the permittivity of free space, q is the electronic charge, ϵ is the dielectric constant of the semiconductor (taken as 41 for anatase TiO 2 ), E is the applied potential, E fb is the flat band potential and N D is the donor density. The flat band potentials were determined by the extrapolation of fitting linear region of the Mott‐Schottky plot.…”

Section: Resultsmentioning

confidence: 99%

N/Al‐Incorporated TiO₂Nanocompositesfor Improved Device Performance of aDye‐Sensitized Solar Cell

et al. 2017

View full text Add to dashboard Cite

We report application of aluminium co-doped with nitrogen titania nanocomposite (Al/N-TiO 2 ) prepared by hydrothermal method as photoanode for very efficient dye-sensitized solar cell (DSSC). The Al/N-TiO 2 nano-composites are characterized by spectral viz. UV-visible, XRD, FTIR, XPS techniques. TEM, SEM, EDX and BET are used to obtain their particle size, morphology and surface area. The DSSC with Al/N co-doped TiO 2 as photoanode and N719 sensitizer dye exhibited an overall light conversion efficiency of 6.24 %, which is much improved compared to that of un-modified TiO 2 (1.69 %) under 100 mW/ cm 2 light irradiation. The improved efficiency with Al/N codoped TiO 2 is attributed to greater dye loading, increased surface area, rapid interfacial charge transfer, slow charge recombination and strong red shift of light absorption in the visible region as compared with un-doped TiO 2 . The effect of the Al concentration on the current density is studied and optimum Al concentration with N-doped TiO 2 is observed to be 1.0 mole%. The work establishes that the as prepared Al/N codoped TiO 2 is impending photoanode material for low-cost and high-efficiency DSSC.

show abstract

Properties and photochemistry of valence-induced-Ti³⁺enriched (Nb,N)-codoped anatase TiO₂semiconductors

Cited by 24 publications

References 27 publications

Improving the Selectivity of Photocatalytic NO_x Abatement through Improved O₂ Reduction Pathways Using Ti_0.909W_0.091O₂N_x Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

Improving the Selectivity of Photocatalytic NO_x Abatement through Improved O₂ Reduction Pathways Using Ti_0.909W_0.091O₂N_x Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

Effect of Particle Size on the Performance of TiO₂ Based Dye‐Sensitized Solar Cells

N/Al‐Incorporated TiO₂Nanocompositesfor Improved Device Performance of aDye‐Sensitized Solar Cell

Contact Info

Product

Resources

About

Properties and photochemistry of valence-induced-Ti3+enriched (Nb,N)-codoped anatase TiO2semiconductors

Cited by 24 publications

References 27 publications

Improving the Selectivity of Photocatalytic NOx Abatement through Improved O2 Reduction Pathways Using Ti0.909W0.091O2Nx Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

Improving the Selectivity of Photocatalytic NOx Abatement through Improved O2 Reduction Pathways Using Ti0.909W0.091O2Nx Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

Effect of Particle Size on the Performance of TiO2 Based Dye‐Sensitized Solar Cells

N/Al‐Incorporated TiO2Nanocompositesfor Improved Device Performance of aDye‐Sensitized Solar Cell

Contact Info

Product

Resources

About

Properties and photochemistry of valence-induced-Ti³⁺enriched (Nb,N)-codoped anatase TiO₂semiconductors

Improving the Selectivity of Photocatalytic NO_x Abatement through Improved O₂ Reduction Pathways Using Ti_0.909W_0.091O₂N_x Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

Improving the Selectivity of Photocatalytic NO_x Abatement through Improved O₂ Reduction Pathways Using Ti_0.909W_0.091O₂N_x Semiconductor Nanoparticles: From Characterization to Photocatalytic Performance

Effect of Particle Size on the Performance of TiO₂ Based Dye‐Sensitized Solar Cells

N/Al‐Incorporated TiO₂Nanocompositesfor Improved Device Performance of aDye‐Sensitized Solar Cell