Improving SERS sensitivity of TiO₂ by utilizing the heterogeneity of facet-potentials

Abstract

Herein, the heterogeneity of the facets potentials is used to improve the SERS activity of anatase TiO2 single crystals co-exposed with {0 0 1} and {1 0 1} facets. Using...

Plasmonic Spherical Nanoparticles Coupled with Titania Nanotube Arrays Prepared by Anodization as Substrates for Surface-Enhanced Raman Spectroscopy Applications: A Review

“…In terms of appropriate crystalline phases for SERS applications, it has been indicated that a mixture of anatase and rutile might help in ameliorating the activity [78][79][80]. So, in order to compare different crystalline phases in SERS experiments, Pisarek and collaborators annealed the as-prepared TiO 2 NTs at 450 • C and 650 • C for 3 h. For the lower temperature, the anatase phase was obtained, which was covered with a silver deposit of 0.015 mg/cm 2 ; by annealing the nanotubes at 650 • C a mixture of anatase and rutile phases were obtained, which were covered with 0.010 mg/cm 2 silver deposit.…”

“…Using a 4-mercaptobenzoic acid as a molecular probe it was shown that mixed crystal structure favors a SERS enhancement with respect to pure anatase or rutile phases due to TiO 2 -to-molecule charge transfer mech-anism and synergistic effect between rutile and anatase phases. The influence of crystalline phases was also explored by Zheng and co-workers who reported the enhancement of SERS sensitivity of TiO 2 depending on the exposed facets [79]. They analyzed TiO 2 single crystals with {0 0 1} and {1 0 1} facets co-exposed, and looked on the variations of the SERS response at different rations between the {0 0 1} and {1 0 1} facets; it was observed that molecules preferred to adsorb on defective {0 0 1} facets, although their SERS response was not proportional to that of enlarged {0 0 1} facets.…”

Surface plasmon-driven photoelectrochemical water splitting of a Ag/TiO2 nanoplate photoanode

“…Therefore, the transfer-enhancement synergistic mechanism is proposed to understand the role of the plasmonic effect of Ag NPs. 47,48 According to our previous study, 47 it was found that protons (H + ) and uoride ions (F À ) play a synergistic role in controlling the morphology and crystal phases of TiO 2 . The ion of F À changes the crystal phases of TiO 2 from rutile to anatase with low-index facets, while increasing amount of H + promotes the growth of the {001} facet.…”

Turbulence enhanced ferroelectric-nanocrystal-based photocatalysis in urchin-like TiO2/BaTiO3 microspheres for hydrogen evolution

“…It has been widely studied as one of the most important photocatalysts since 1972 [1][2][3][4][5][6][7][8][9][10][11] . However, TiO 2 only absorbs ultraviolet (UV) light of broad solar spectrum due to its large bandgap energy (λ < 380 nm), which is comprised of only ~3% of sunlight [12][13][14] . Many efforts have focused on the development of broadband response nanomaterials with spectrum response from the UV to the visible 10,[15][16][17][18][19][20][21][22][23][24] , even to the infrared (IR) region 18,20,[25][26][27][28][29] .…”

“…TiO 2 heterostructures 3,13,[41][42][43][44] . In addition, by preparing TiO 2 polyhedrons with different exposed crystal facets, carrier transfer is generated by using different crystal face level structures 12,[45][46][47] . The former method has certain limitations in promoting carrier separation.…”