Single-/Few-Layer Graphene as Long-Lasting Electrocatalyst for Hydrogen Evolution Reaction

The development of carbonaceous materials electrocatalytically active for water splitting reactions could overcome multiple disadvantages of metallic catalysts, including high cost, low selectivity, poor durability, and susceptibility to evolved gas. General guidelines to design carbon-based hydrogen evolution reaction (HER) electrocatalysts still remain a topic of debate. Here, we identify single-/few-layer graphene flakes with defective edges (SLG/FLG-DE), produced by hydrogen peroxide-assisted cosolvent liquid phase exfoliation, as durable and efficient HER electrocatalysts. The SLG/FLG-DE display overpotentials at 10 mA cm–2 of 55 and 85 mV in 0.5 M H2SO4 and 1 M KOH solutions, respectively, as well as a durable HER activity over 200 h.