Synthesis of Graphene/Platinum Nanoparticle Composite Aerogels By Self-Assembly

Jordan M. Davis^*, Duncan R. Day^*, Brigit A. Duffy, Gabrielle M. Milanesa, Enoch A. Nagelli

Department of Chemistry & Life Science, Chemical Engineering Program, United States Military Academy, West Point, New York 10996

Abstract

Graphene aerogels are an ideal nanostructured material for integration with other solid-state electrode materials to produce lightweight and high energy density batteries. Graphene oxide nanocomposites offer high surface area for fast electron transport and large surface area for ion intercalation. When combined with aqueous Magnus’s salts made up of platinum and chemically reduced, these unique properties are combined to form a conductive and electrocatalytic porous material. We present an all-solution based synthesis via bottom-up self-assembly of graphene/platinum (G/Pt) aerogels. The purpose of our study is to investigate the ideal concentrations of Magnus’s salts and graphene oxide to form high surface area aerogels with both filtration and centrifugation techniques. In this study, we focus on the integration of platinum nanoparticles with graphene for enhanced conductivity and catalytic activity throughout the 3D nanocomposite structure. Combining the positively and negatively charged coordinated platinum complexed ions to form Magnus’s salts (concentrations ranging from 10 mM to 200 mM) with graphene oxide in aqueous solution (~1 mg/mL) creates a network that, once chemically reduced with a reducing agent (sodium borohydride), is conductive. The resulting G/Pt nanocomposite solid material can then be dried with supercritical super critically dried to form compact, porous, high surface area, and lightweight aerogels or filtered during the chemical reduction process to make ultra-thin films. We characterize the resulting G/Pt nanocomposite structure using Raman spectroscopy and scanning electron microscopy (SEM). Our demonstrated G/Pt nanocomposite synthesis via self-assembly can potentially be a general methodology with any carbon nanomaterial and noble metal to help advance the scalable development of aqueous solution processes to produce a lightweight, high-power, and energy dense aerogels and film electrodes.

KEYWORDS: Graphene, Platinum Nanoparticles, Aerogel, Thin Films, Self-Assembly, Magnus Salts, Batteries

CONTACT: Dr. Enoch Nagelli, Department of Chemistry and Life Science, United States Military Academy, West Point, New York 10996. Email: enoch.nagelli@westpoint.edu

*Authors contributed equally to this work.