Ice-templated synthesis of multifunctional three dimensional graphene/noble metal nanocomposites and their mechanical, electrical, catalytic, and electromagnetic shielding properties.

P. K. Sahoo,Himanshu Sekhar Panda,Radhamanohar Aepuru,D. Bahadur

doi:10.1038/srep17726

Abstract

In-situ homogeneous dispersion of noble metals in three-dimensional graphene sheets is a key tactic for producing macroscopic architecture, which is desirable for practical applications, such as electromagnetic interference shielding and catalyst. We report a one-step greener approach for developing porous architecture of 3D-graphene/noble metal (Pt and Ag) nanocomposite monoliths. The resulting graphene/noble metal nanocomposites exhibit a combination of ultralow density, excellent elasticity, and good electrical conductivity. Moreover, in order to illuminate the advantages of the 3D-graphene/noble metal nanocomposites, their electromagnetic interference (EMI) shielding and electrocatalytic performance are further investigated. The as-synthesized 3D-graphene/noble metal nanocomposites exhibit excellent EMI shielding effectiveness when compared to bare graphene; the effectiveness has an average of 28 dB in the 8.2–12.4 GHz X-band range. In the electro-oxidation of methanol, the 3D-graphene/Pt nanocomposite also exhibits significantly enhanced electrocatalytic performance and stability than compared to reduced graphene oxide/Pt and commercial Pt/C.

Highlights

Solar cells[18], high-performance lithium ion batteries[19], and electromagnetic interference (EMI) shielding[20]
We demonstrated the fabrication of 3D-graphene/noble metal (Pt and Ag) nanocomposites by using a low cost wet shaping technique, which generally called freeze casting
Freeze casting method has been widely implemented for preparing variety of porous materials[28,30,33,34,35,36,37,38]

Summary

Introduction

Solar cells[18], high-performance lithium ion batteries[19], and EMI shielding[20] In these composite materials, graphene powder (that is, chemically exfoliated graphene oxide (GO) and reduced graphene oxide (RGO))[7,13,21,22] has been considered as a supporting material. Qiu Ling et al have reported ultra-light 3D-graphene–based cellular monoliths using a cost-efficient freeze-casting process with ultra-low density, superelasticity, good electrical conductivity, and high-energy absorption efficiency[30]. Such an uncommon carbon-based cellular material opens up numerous opportunities in an extensive variety of innovative applications. Our objective is to fabricate 3D-graphene/noble metal (Pt or Ag) nanocomposites by taking advantage of this 3D-graphene monolith structure for EMI shielding and methanol fuel cell applications. In the electro-oxidation of methanol, 3D-graphene/Pt nanocomposites show excellent electrocatalytic properties such as a high electrocatalytic performance, abnormal poison tolerance, and dependable stability, which are of a higher grade compared to those of Pt/reduced graphene oxide nanocomposites and commercial Pt/C

Objectives

Methods

Results

Conclusion