Network of Palladium-Based Nanorings Synthesized by Liquid-Phase Reduction Using DMSO-H2O: In Situ Monitoring of Structure Formation and Drying Deformation by ASEM.

Takuki Komenami,Yasunari Matsuno,Chikara Sato,Akihiro Yoshimura,Mari Sato

doi:10.3390/ijms21093271

Abstract

We developed a liquid-phase synthesis method for Pd-based nanostructure, in which Pd dissolved in dimethyl sulfoxide (DMSO) solutions was precipitated using acid aqueous solution. In the development of the method, in situ monitoring using atmospheric scanning electron microscopy (ASEM) revealed that three-dimensional (3D) Pd-based nanonetworks were deformed to micrometer-size particles possibly by the surface tension of the solutions during the drying process. To avoid surface tension, critical point drying was employed to dry the Pd-based precipitates. By combining ASEM monitoring with critical point drying, the synthesis parameters were optimized, resulting in the formation of lacelike delicate nanonetworks using citric acid aqueous solutions. Precipitation using HCl acid aqueous solutions allowed formation of 500-nm diameter nanorings connected by nanowires. The 3D nanostructure formation was controllable and modifiable into various shapes using different concentrations of the Pd and Cl ions as the parameters.

Highlights

Precious metal nanomaterials, especially Au, Pt, and Pd, have attracted significant attention in a wide range of fields such as chemical catalysts, nanotechnology, and material chemistry owing to their unique electrical, catalytic, and optical properties [1,2]
These results suggest that a 3D Pd-based nanostructure formed in the liquid was deformed into micrometer-size spherical particles during the drying process
It is assumed that the function of the Cl ion concentration and the function of dimethyl sulfoxide (DMSO) molecules plays an important role in the formation of 3D nanostructures

Summary

Introduction

Especially Au, Pt, and Pd, have attracted significant attention in a wide range of fields such as chemical catalysts, nanotechnology, and material chemistry owing to their unique electrical, catalytic, and optical properties [1,2]. Pd has excellent catalytic activity for organic synthesis and exhaust gas purification [5,6]. In these industrial fields, the large surface area and high catalytic performance of Pd nanomaterials are of major interest in improving the reaction efficiency and selectivity [5,7]. Hydrothermal methods, electrochemical deposition, chemical reductions, etc. Hydrothermal methods, electrochemical deposition, chemical reductions, etc. have been investigated for the synthesis of Pd and Pd-based nanomaterials [8]

Methods

Results

Discussion

Conclusion