Tsukuba, Japan--Hydrogen produced from water by the hydrogen evolution reaction is an attractive clean fuel source.
Production of hydrogen on a large scale at low cost is necessary to realize its viability as an alternative energy source to fossil fuels.
Most present catalysts based on non-precious metals suffer from instability in the acidic solutions formed during hydrogen evolution.
However, simply protecting the catalyst from the acidic solution tends to lower its activity.
The team found that coating catalyst nanoparticles with an optimal number of layers of graphene--a sheet of carbon atoms organized into a honeycomb lattice with high conductivity and mechanical strength--raised nanoparticle durability while allowing the nanoparticles to retain their catalytic activity.
"We optimized the balance between the number of graphene layers coating the nanoparticles and their catalytic activity," study first author Kailong Hu says.