Plasmonic hot carrier-driven oxygen evolution reaction on Au nanoparticles/TiO2 nanotube arrays

• Published in: Nanoscale Vol. 10; no. 47; pp. 22180 - 22188
• Main Authors: Song Yi Moon, Hee Chan Song, Eun Heui Gwag, Nedrygailov, Ievgen I, Lee, Changhwan, Jeong Jin Kim, Won Hui Doh, Jeong Young Park
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 21.12.2018
• Subjects: Atomic force microscopy; Catalytic activity; Decay; Electron density; Gold; Hot electrons; Microscopy; Nanoparticles; Nanotubes; Noble metals; Oxygen evolution reactions; Photocatalysis; Photoelectric effect; Photoelectric emission; Photoelectrons; Reflectance; Spectrum analysis; Titanium dioxide; Water splitting
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr05144e

The use of hot carriers generated from the decay of localized surface plasmon resonance in noble metal nanoparticles is a promising concept for photocatalysis. Here, we report the enhancement of photocatalytic activity by the flow of hot electrons on TiO2 nanotube arrays decorated with 5–30 nm Au nanoparticles as photoanodes for photoelectrochemical water splitting. This enhanced photocatalytic activity is correlated to the size of the Au nanoparticles, where higher oxygen evolution was observed on the smaller nanoparticles. Conductive atomic force microscopy and ultraviolet photoelectron spectroscopy were used to characterize the Schottky barrier between Au and TiO2, which reveals a reduction in the Schottky barrier with the smaller Au nanoparticles and produces an enhanced transfer of photoinduced hot carriers. This study confirms that the higher photocatalytic activity was indeed driven by the hot electron flux generated from the decay of localized surface plasmon resonance.