The Polarization Effect in Surface‐Plasmon‐Induced Photocatalysis on Au/TiO₂ Nanoparticles

Abstract

Controlling the interaction of polarization light with an asymmetric nanostructure such as a metal/semiconductor heterostructure provides opportunities for tuning surface plasmon excitation and near‐field spatial distribution. However, light polarization effects on interfacial charge transport and the photocatalysis of plasmonic metal/semiconductor photocatalysts are unclear. Herein, we reveal the polarization dependence of plasmonic charge separation and spatial distribution in Au/TiO2 nanoparticles under 45° incident light illumination at the single‐particle level using a combination of photon‐irradiated Kelvin probe force microscopy (KPFM) and electromagnetic field simulation. We quantitatively uncover the relationship between the local charge density and polarization angle by investigating the polarization‐dependent surface photovoltage (SPV). The plasmon‐induced photocatalytic activity is enhanced when the polarization direction is perpendicular to the Au/TiO2 interface.

Plasmonic Charge Transfers in Large‐Scale Metallic and Colloidal Photonic Crystal Slabs

“…[ 49 ] In all these cases, where metals are included, we observe a slow rise and a relatively faster fall in the photoresponse except at cPhC slabs, where the additional PR layer increases the decay time. At 565 and 660 nm light exposures, we observe current modulation due to the charge transfers mediated by localized surface plasmon resonance of single nanoparticles [ 50 ] at 504 nm and aggregations [ 51 ] at 686 nm, (Figure S5c, Supporting Information), respectively. For the mPhC slabs, periodic exposure at 565 nm creates a weak photoresponse covered with background noises; the response becomes stronger as the excitation wavelength is increased toward the hybrid modes.…”

Investigation of the Plasmon-Activated C–C Coupling Reactions by Liquid-State SERS Measurement

“…26−29 It is also possible to transfer the hot carriers to neighboring catalysts like semiconductors and transition metals to facilitate the heterogeneous reactions on their surfaces. 30,31 The combination of ultrasensitive chemically specific detection and the ability to generate hot carriers endows plasmonic materials the ability to visualize and manipulate the heterogeneous catalysis at a subatomic level. Their potential has been demonstrated in a wide range of heterogeneous catalyses including water splitting, 32,33 Suzuki−Miyaura reactions, 31,34 and CO 2 reduction.…”

Preparation of Bi3Fe0.5Nb1.5O9/g-C3N4 heterojunction photocatalysts and applications in the photocatalytic degradation of 2,4-dichlorophenol in environment

“…Fortunately, polarization has become one of the most effective strategies to overcome the above problems and greatly promotes photocatalysis efficiency. [15][16][17][18][19] Bi 3 Fe 0.5 Nb 1.5 O 9 (BFNO) is selected and used to form a spontaneous polarized electric field. Without external stress, a spontaneous polarized electric field is generated to drive the photogenerated carriers.…”