Electric Field Effect on the Reactivity of Solid State Materials: The Case of Single Layer Graphene

This manuscript reports the first example of charge-doping-induced reactivity enhancement in macroscopic-sized solid state material. Single layer graphene is supported on a Si wafer that has a 300 nm thick SiO2 layer and is heated photothermally in air to approximate to 240 degrees C. Applying both positive and negative pulsed back gate voltages increases the rate of graphene oxidation, as measured by the change of I-D/I-G ratio using Raman spectroscopy. The fact that both electron and hole doping increase the reactivity argues against electrochemical oxidation and suggests a new mechanism is at play. The enhancement effect increases with the magnitude and the frequency of the square wave back gate voltage. Density functional theory calculations indicate that the activation barriers for O-2 insertion into graphene and desorption of CO2 decrease in the presence of an electric field. This study suggests charge doping as a new approach that can modulate the reactivity of solid state materials in real time and compliment chemical-based catalysis