Morphological Growth and Theoretical Understanding of Gold and Other Noble Metal Nanoplates. Issue 58 (13th September 2018)

• Record Type: Journal Article
• Authors: Xia, Jing; Dong, ZhiLi; Cai, Yongqing; Guan, Guijian; Zhang, Shuangyuan; Kovács, András; Boothroyd, Chris; Phang, In Yee; Liu, Shuhua; Wu, Mingda; Zhang, Yong Wei; Hu, Xiao; Han, Ming‐Yong
• Is Part Of: Chemistry. Volume 24:Issue 58(2018)
• Page Start: 15589
• Page End: 15595
• Publication Date: 2018-09-13
• Subjects: anisotropic growth -- chemical reduction -- disproportionation -- gold -- nanostructures; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201802372
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: For the last decades, the chemical reduction of Au 3+ to Au 0 has been widely employed to produce various gold nanostructures. In comparison with the fast reduction, the slow reduction is systematically investigated in this research to provide more insights to reveal intermediary process and further disclose the underlying mechanism for growing gold nanostructures by using a series of simple ligands with aldehyde groups as weak reducing agents. The different binding energies of ligands to Au n + ( n =3, 1 and 0) exhibit variable binding affinities in starting, intermediate, and final gold species. For example, formic acid has much stronger binding affinity to Au + than Au 3+, and thus Au + intermediate is able to be stabilized/captured during slow reduction of Au 3+ . Upon the disproportionation of Au + to Au 0 and Au 3+, formic acid has much stronger binding affinity to the newly formed Au 0 than other ligands for the controlled formation of gold nanostructures. Meanwhile, the adsorption of ligands causes substantially decreased surface energies on different gold planes. There are much higher energies on {110} planes compared to the other two {111} and {100} planes with certain ratios in these energies, leading to morphological growth of gold nanosheets. In this paper, we experimentally demonstrate anisotropic growth of gold nanosheets by using various ligands with weak reducing and appropriate coordination capabilities, and further provide insights to understand their morphological growth mechanism behind. This synthetic strategy is successfully extended to prepare silver, palladium, and platinum nanoplates. Abstract : Going for gold : A facile method has been developed to synthesize gold nanostructures and investigate their formation mechanism by using various ligands with weak reducing and appropriate coordination capabilities, providing insights to the underlying growth mechanism for the formation of intermediate Au + during retarded reduction. The morphology of the anisotropic gold nanostructures is controlled by surface energies of ligand‐bound gold planes with certain energy ratios and binding affinities of ligands to Au 0 .