Plasmonic Au nanoparticles on 8 nm TiO2 nanotubes for enhanced photocatalytic water splitting

Abstract

We report here for the first time a successful distribution and attachment of fine Au nanoparticles on ∼8 nm diameter TiO2 nanotubes having significantly increased surface area. Au thin film deposition onto hydrothermally grown TiO2 nanotube arrays followed by thermal annealing breaks up the Au film into desired, uniformly distributed nanoparticles. Visible light absorption spectra of the gold nanoparticles on TiO2 nanotubes indicate that the Au nanoparticles are photo-excited due to plasmon resonance, and charge separation is accomplished by the transfer of photoexcited electrons from the gold particle to the TiO2 conduction band, thereby enhancing photoelectrochemical performance. By virtue of substantially increased surface area with the 8 nm TiO2 nanotube substrate in combination with the plasmonic effect of distributed Au nanoparticles, significantly increased photocurrent density was obtained with extended light absorbance from the UV regime to the visible spectrum region. Such gold nanoparticle decorated, fine TiO2 nanostructures fabricated by a simple and versatile method can be useful for hydrogen generation by water splitting, CO oxidation and various other types of photocatalysts and photovoltaic fuel cells.

Surface modification of aligned CdO nanosheets and their enhanced field emission properties

“…Coalescence of Au nanoparticles examined the larger diameter with an increase in Au thin lm thickness also the decrement in the density of Au nanoparticles is observed. 31 A careful observation of FESEM images of specimen D indicate ineffective formation of nanoparticles (at a few sections of specimen) from Au thin lm deposited for the time duration of 60 s (ESI S1 †). Therefore, Au lm of time duration more than 60 s was not deposited on porous CdO nanosheets.…”

Strong Light–Matter Interactions in Au Plasmonic Nanoantennas Coupled with Prussian Blue Catalyst on BiVO4 for Photoelectrochemical Water Splitting

“…These metallic nanoparticles act as an electron trapping center, which captures the photocarriers and hampers their collection efficiency. That is why an optimum metal loading is required to make the necessary trade‐off for performance improvement . Another approach could be the use of a proper catalyst for the selective isolation of photogenerated carriers to enhance their lifetime .…”

Strong Light–Matter Interactions in Au Plasmonic Nanoantennas Coupled with Prussian Blue Catalyst on BiVO4 for Photoelectrochemical Water Splitting

“…These metallicn anoparticles act as an electron trapping center,which captures the photocarriers and hampers their collection efficiency.T hat is why an optimum metal loading is required to make the necessary trade-off for performance improvement. [40][41][42] Another approachc ould be the use of ap roperc atalystf or the selectivei solation of photogenerated carriers to enhancet heir lifetime. [33,36] Therefore, in an ideal scheme, al ow band gap semiconductor loaded with a plasmonic-catalyst heterostructure with selective decoration can reveal superior opto-electronic and catalytic properties.…”