Researchers embed graphene with metallic nanoparticles
Post Date: 21 Aug 2015 Viewed: 422
New research shows that when embedded with metallic nanoparticles, graphene can take on metallic qualities, and even serve as a potential substitute for platinum as a fuel catalyst.
Metals like platinum are vital to the catalytic fuel cells that convert oxygen and hydrogen into electricity and water. The problem is platinum and other similarly used noble metals are expensive, but researchers have happened upon a relatively inexpensive solution.
Recently, while experimenting inside the labs of Rice University, scientists found that laser-induced grapheme flecked with tiny metal salts took on properties of noble metals like platinum.
First, a flexible and porous graphene film is made by exposing a common plastic polyimide to pulsed laser irradiation. Next, the plastic-turned-graphene film is textured with metallic nanoparticles.
"The wonderful thing about this process is that we can use commercial polymers, with simple inexpensive metal salts added," Rice chemist James Tour said in a press release. "We then subject them to the commercial laser scriber, which generates metal nanoparticles embedded in graphene. So much of the chemistry is done by the laser, which generates graphene in the open air at room temperature."
In followup testing, Tour and his colleagues found the metallic film capable of catalyzing oxygen reduction, a key chemical reaction that jump starts energy production in fuel cells.
When the scientists treated the metallic film with sulfur, they found it capable of catalyzing hydrogen evolution, a similarly important fuel cell reaction.
"Remarkably, simple treatment of the graphene-molybdenum oxides with sulfur, which converted the metal oxides to metal sulfides, afforded a hydrogen evolution reaction catalyst, underscoring the broad utility of this approach," Tour said.