Probing of coupling effect induced plasmonic charge accumulation for water oxidation

Abstract

<jats:title>Abstract</jats:title> <jats:p>A key issue for redox reactions in plasmon-induced photocatalysis, particularly for water oxidation, is the concentration of surface-accumulating charges (electrons or holes) at a reaction site for artificial photosynthesis. However, where plasmonic charge accumulated at catalysts surface and how to improve local charge density at active sites remains unknown because it is difficult to identify the exact spatial location and local density of the plasmon-induced charge, particularly hole. Herein, we show that at the single particle level, plasmon-coupling-induced hole can be greatly accumulated at the plasmonic Au nanoparticle dimer/TiO2 interface in the nanogap region, as directly evidenced by the locally enhanced surface photovoltage. Such an accumulation of plasmonic hole can significantly accelerate the water oxidation reaction (multi-holes involved) at the interfacial reaction site, with nearly one order of magnitude enhancement in the photocatalytic activities compared to those of highly dispersed Au nanoparticles on TiO2. Combining Kelvin probe force microscopy and theoretical simulation, we further clarified that the local accumulated hole density is proportional to the square of the local near-field enhancement. Our findings advance the understanding of how charges spatially distribute in plasmonic systems and the specific role of local charge density at reaction sites played in plasmonic photocatalysis.</jats:p>

Serum Metabolic Fingerprints on Bowl-Shaped Submicroreactor Chip for Chemotherapy Monitoring

“…, plasmonic hot spots). 47 When comparing the different Au loadings, the APF-bowl&0.96Au exhibited superior capability in small metabolite detection ( Figure 2 a–e) because of its desirable distribution of nanoscaled cavities within Au nanoparticles for higher yield of hot carriers, in line with the EM field simulation results ( Figure 2 g–i). In addition, we demonstrated the optimized Au loading content of APF-bowl&0.96Au contributes to the size-exclusive effect for selective trapping of small metabolites and excluding the macromolecules ( e.g.…”

Boosting Photocatalytic Hydrogen Evolution Reaction Using Dual Plasmonic Antennas

“…One emerging way is the fabrication of plasmonic metal–semiconductor nanocomposites that display much more tunable optical properties. Light incident on the surface of the plasmonic metal nanostructures can excite localized surface plasmon resonance (LSPR), that is, collective oscillation of electrons, − which allows the nanostructures to superiorly capture and modulate light from the ultraviolet–visible (UV–vis) to near-infrared range. − Therefore, plasmonic materials are widely used in various photophysical and photochemical processes including solar cells, , photocatalysis, , photodetection, , and so forth and can significantly improve the energy utilization efficiency. , …”

“…Light incident on the surface of the plasmonic metal nanostructures can excite localized surface plasmon resonance (LSPR), that is, collective oscillation of electrons, 5−7 which allows the nanostructures to superiorly capture and modulate light from the ultraviolet−visible (UV−vis) to near-infrared range. 8−10 Therefore, plasmonic materials are widely used in various photophysical and photochemical processes including solar cells, 11,12 photocatalysis, 13,14 photodetection, 15,16 and so forth and can significantly improve the energy utilization efficiency. 17,18 One well-known mechanism to improve the photocatalytic efficiency using LSPR is plasmon-induced resonance energy transfer (PRET).…”

Ultrathin Cobalt Oxide Interlayer Facilitated Hole Storage for Sustained Water Oxidation over Composited Tantalum Nitride Photoanodes

“…To elucidate the effect of CoO x /Ni­(OH) x bilayer decoration in photogenerated charge separation behaviors at the nanometer scale, the steady-state CPD measurements were conducted under 450 nm monochromatic light. A CPD variation value, termed as surface photovoltage (SPV), reflects the local charge density change of the sample surface caused by charge generation, separation, and transfer processes, closely related to the driving force for photogenerated holes via irradiation. − As presented in Figure b, it could be clearly seen that upon turning on the light, the SPV values of all studied electrodes increase due to the photogenerated hole migration toward the electrode surface, and once the light is turned off, they will return to the initial value. It is also noticeable that the SPV value for the individual addition of the CoO x or Ni­(OH) x layer is comparable with that of pristine Ta 3 N 5 .…”