Synthesis of Au nanorods via autocatalytic growth of Au seeds formed by sonochemical reduction of Au(I): Relation between formation rate and characteristic of Au nanorods

Kenji Okitsu; Satoshi Semboshi

doi:10.1016/j.ultsonch.2020.105229

Synthesis of Au nanorods via autocatalytic growth of Au seeds formed by sonochemical reduction of Au(I): Relation between formation rate and characteristic of Au nanorods

Ultrason Sonochem. 2020 Dec:69:105229. doi: 10.1016/j.ultsonch.2020.105229. Epub 2020 Jun 24.

Authors

Kenji Okitsu¹, Satoshi Semboshi²

Affiliations

¹ Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan. Electronic address: okitsu@mtr.osakafu-u.ac.jp.
² Institute for Materials Research, Tohoku University, Katahira 2-1-1 Aoba-ku, Sendai, Miyagi 980-8577, Japan.

PMID: 32623344
DOI: 10.1016/j.ultsonch.2020.105229

Abstract

The sonochemical formation of Au seeds and their autocatalytic growth to Au nanorods were investigated in a one-pot as a function of concentration of HAuCl₄, AgNO₃, and ascorbic acid (AA). The effects of ultrasonic power and irradiation time were also investigated. In addition, the formation rate of Au nanorods was analyzed by monitoring the extinction at 400 nm by UV-Vis spectroscopy and compared with the growth behavior of Au seeds to nanorods. Most of the reaction conditions affected the yield, size, and shape of Au nanorods formed. It was confirmed that the concentration balance between HAuCl₄ and AA was important to proceed the formation of Au seeds and nanorods effectively. The formation rate became faster with increasing AA concentration and dog-bone shaped nanorods were formed at high AA concentration. It was also confirmed a unique phenomenon that the shape of Au nanorods changed even after the completion of the reduction of Au(I) in the case of short-time ultrasonic irradiation for Au seed formation.

Keywords: Au nanorod; Au seed; Autocatalytic growth; Autocatalytic reduction; Sonochemical reduction.