Limits...
Hot plasmonic electrons for generation of enhanced photocurrent in gold-TiO2 nanocomposites.

Brennan LJ, Purcell-Milton F, Salmeron AS, Zhang H, Govorov AO, Fedorov AV, Gun'ko YK - Nanoscale Res Lett (2015)

Bottom Line: The composite film demonstrates a significant increase in the short circuit current (I sc) compared to unmodified TiO2 when excited at or close to the plasmon resonance of the gold nanoparticles.Photo-electrochemical investigations revealed that the increase in photocurrent is attributed to the generation and separation of plasmonically generated hot electrons at the gold/TiO2 interface and also the inter-band generation of holes in gold nanoparticles by photons with λ < 520 nm.Theoretical modelling outputs perfectly match our results obtained from photo-physical studies of the processes leading to enhanced photocurrent.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry and CRANN Institute, Trinity College Dublin, Dublin 2, Ireland.

ABSTRACT
In this manuscript, for the first time, we report a combination of electrophoretic and sintering approaches for introducing gold nanoparticles into nanoporous TiO2 films to generate 'hot' electrons resulting in a strong enhancement of photocurrent. The Au-TiO2 nanocomposite material was prepared by the electrophoretic deposition of gold nanoparticles into a porous nanoparticulate titanium dioxide film, creating a photoactive electrode. The composite film demonstrates a significant increase in the short circuit current (I sc) compared to unmodified TiO2 when excited at or close to the plasmon resonance of the gold nanoparticles. Then, we employed a thermal ripening process as a method of increasing the I sc of these electrodes and also as a method of tuning the plasmon peak position, with a high degree of selectivity. Photo-electrochemical investigations revealed that the increase in photocurrent is attributed to the generation and separation of plasmonically generated hot electrons at the gold/TiO2 interface and also the inter-band generation of holes in gold nanoparticles by photons with λ < 520 nm. Theoretical modelling outputs perfectly match our results obtained from photo-physical studies of the processes leading to enhanced photocurrent.

No MeSH data available.


Related in: MedlinePlus

Comparison of IPCE and absorption spectra for both experiment (A) and theory (B). In the theoretical graph (B), we show only the hot-electron contribution.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4385105&req=5

Fig6: Comparison of IPCE and absorption spectra for both experiment (A) and theory (B). In the theoretical graph (B), we show only the hot-electron contribution.

Mentions: The comparison of the experimental and theoretically calculated absorption and IPCE spectra is shown in Figure 6. The plasmonic peak in the ΔIPCE in both experiment and theory is red-shifted. This effect can be explained in the following way: This peak originates from the over-barrier injection of hot plasmonic carriers. The generation rate in this case is wavelength-dependent and proportional to (see also Additional file 1):Figure 6


Hot plasmonic electrons for generation of enhanced photocurrent in gold-TiO2 nanocomposites.

Brennan LJ, Purcell-Milton F, Salmeron AS, Zhang H, Govorov AO, Fedorov AV, Gun'ko YK - Nanoscale Res Lett (2015)

Comparison of IPCE and absorption spectra for both experiment (A) and theory (B). In the theoretical graph (B), we show only the hot-electron contribution.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385105&req=5

Fig6: Comparison of IPCE and absorption spectra for both experiment (A) and theory (B). In the theoretical graph (B), we show only the hot-electron contribution.
Mentions: The comparison of the experimental and theoretically calculated absorption and IPCE spectra is shown in Figure 6. The plasmonic peak in the ΔIPCE in both experiment and theory is red-shifted. This effect can be explained in the following way: This peak originates from the over-barrier injection of hot plasmonic carriers. The generation rate in this case is wavelength-dependent and proportional to (see also Additional file 1):Figure 6

Bottom Line: The composite film demonstrates a significant increase in the short circuit current (I sc) compared to unmodified TiO2 when excited at or close to the plasmon resonance of the gold nanoparticles.Photo-electrochemical investigations revealed that the increase in photocurrent is attributed to the generation and separation of plasmonically generated hot electrons at the gold/TiO2 interface and also the inter-band generation of holes in gold nanoparticles by photons with λ < 520 nm.Theoretical modelling outputs perfectly match our results obtained from photo-physical studies of the processes leading to enhanced photocurrent.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry and CRANN Institute, Trinity College Dublin, Dublin 2, Ireland.

ABSTRACT
In this manuscript, for the first time, we report a combination of electrophoretic and sintering approaches for introducing gold nanoparticles into nanoporous TiO2 films to generate 'hot' electrons resulting in a strong enhancement of photocurrent. The Au-TiO2 nanocomposite material was prepared by the electrophoretic deposition of gold nanoparticles into a porous nanoparticulate titanium dioxide film, creating a photoactive electrode. The composite film demonstrates a significant increase in the short circuit current (I sc) compared to unmodified TiO2 when excited at or close to the plasmon resonance of the gold nanoparticles. Then, we employed a thermal ripening process as a method of increasing the I sc of these electrodes and also as a method of tuning the plasmon peak position, with a high degree of selectivity. Photo-electrochemical investigations revealed that the increase in photocurrent is attributed to the generation and separation of plasmonically generated hot electrons at the gold/TiO2 interface and also the inter-band generation of holes in gold nanoparticles by photons with λ < 520 nm. Theoretical modelling outputs perfectly match our results obtained from photo-physical studies of the processes leading to enhanced photocurrent.

No MeSH data available.


Related in: MedlinePlus