On the role of localized surface plasmon resonance in UV-Vis light irradiated Au/TiO₂ photocatalysis systems: pros and cons

Abstract

The role of localized surface plasmon resonance (LSPR) in UV-Vis light irradiated Au/TiO2 photocatalysis systems has been investigated, and it is demonstrated experimentally for the first time that both pros and cons of LSPR exist simultaneously for this photocatalytic reaction. We have proved that when operating under mixed UV and green light irradiation, the LSPR injected hot electrons (from the Au nanoparticles to TiO2 under green light irradiation) may surmount the Schottky barrier (SB) formed between the Au nanoparticles and TiO2, and flow back into the TiO2. As a result, these electrons may compensate for and even surpass those transferred from TiO2 to the Au nanoparticles, thus accelerating the recombination of UV excited electron-hole pairs in TiO2. This is the negative effect of LSPR. On the other hand, more hot electrons existing on the surface of the Au nanoparticles due to LSPR would favor the photocatalytic reaction, which accompanied by the negative effect dominates the overall photocatalytic performance. The presented results reveal the multi-faceted essence of LSPR in Au/TiO2 structures, and is instructive for the application of metal-semiconductor composites in photocatalysis. Moreover, it is confirmed that the extent to which the above pros and cons of LSPR dominate the overall photocatalytic reaction depends on the intensity ratio of visible to UV light.

Enhanced photocatalytic activity in Ag-nanoparticle-dispersed BaTiO3 composite thin films: Role of charge transfer

“…9). A similar phenomenon was observed in the UV-Vis light irradiated Au/TiO 2 photocatalysis system although the authors mainly focused on the pros and cons of localized SPR [50]. Table 2 lists the potential energy (1240/λ SPR ) of the hot e  (named hot e h  ) of the Ag x /BTO thin films through the λ SPR of the absorption spectra (Fig.…”

Photocatalytic reduction of CO2over Ag/TiO2nanocomposites prepared with a simple and rapid silver mirror method

“…[4][5] Considerable photocatalysts have recently been explored as the candidate of photoconversion of CO 2 , including InP 6 , TiO 2 7 , CdS 8 , ZnGa 2 O 4 9 , Zn 2 GeO 4 10-11 and metal-organic frameworks, [12][13] and a series of catalysts with novel nanostructures, such as ultrathin nanoribbons, ultrathin nanosheets, to achieve high conversion efficiency. 4 Silver loaded on the surface of TiO 2 shows strong photoabsorption of visible irradiation, which results from the localized surface plasmonic resonance (SPR) 14 . The SPR of Ag nanoparticles can introduce a strong local electronic field in the vicinity of the nanoparticles, which is believed capable of inducing some photocatalysis reactions.…”

Promoting Catalytic Oxygen Activation by Localized Surface Plasmon Resonance: Effect of Visible Light Pre‐treatment and Bimetallic Interactions

“…In recent years, reports on the localized surface plasmon resonance (LSPR) effect has opened up new possibilities for visible light utilization . The LSPR effect relies on the excitation of electrons on the metal surface, which occurs only at a specific frequency corresponding to a specific wavelength that is characteristic of the metal.…”

“…[4][5][6][7][8][9][10] In recent years, reports on the localized surface plasmon resonance( LSPR) effect has opened up new possibilities for visible light utilization. [11][12][13][14][15][16][17] The LSPR effect relies on the excitation of electrons on the metal surface, which occurs only at as pecific frequency corresponding to as pecific wavelength that is characteristic of the metal. The versatility of the LSPR effect, especially in terms of the tunability of excitation wavelength (light absorption range), which can be exploiteds imply by manipulating the nanoparticle size and shape, makes it an interesting and highly valuable property to be brought into catalysis.…”