Enhanced Plasmonic Electron Transfer from Gold Nanoparticles to TiO2 Nanorods via Electrochemical Surface Reduction

Autor: Jong-Won Yun, Tri Khoa Nguyen, Sunghan Lee, Sungdo Kim, Yong Soo Kim, Cao Khang Nguyen, Yang Ha
Rok vydání: 2020
Předmět:
Zdroj: Journal of the Korean Physical Society. 77:853-860
ISSN: 1976-8524
0374-4884
DOI: 10.3938/jkps.77.853
Popis: The transport of charge carriers across the heterojunction of an optoelectronic device plays a crucial role in the performance of the device. This issue is particularly important in the area of heterogeneous metal-semiconducting photocatalysis in terms of harvesting the hot carriers generated under plasmonic resonance. This paper presents the results of a case study on the impact of electrochemical surface reduction on the transport properties of plasmonic electrons, which are generated on gold nanoparticles (Au NPs) under visible light irradiation to TiO2 nanorods (TiO2 NRs). Based on microscopic and spectroscopic characterizations, this study examined the subtle changes in the structural and the optical properties of the Au NPs/TiO2 NRs upon surface reduction of the oxygen layer which is ubiquitous on TiO2 NRs. These results suggest that the oxygen layer works as a blocking layer that limits the charge transfer efficiency of plasmonic electrons from Au to TiO2 and, consequently, reduces the device performance. The main thesis was verified directly by comparing the photocatalytic activities of pristine Au NPs/TiO2 NRs and Au NPs/reduced TiO2 NRs with methylene blue as a reference. The photocatalytic performance of the Au NPs/reduced TiO2 NRs was two times higher than that of the pristine one owing to the efficient charge transfer across the Au/TiO2 interface. This simple surface treatment can be employed widely to enhance the charge transport efficiency of various optoelectronic materials and devices derived from metal-semiconducting heterostructures.
Databáze: OpenAIRE
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