Quartz crystal microbalance monitoring of large-area graphene anodization reveals layer fracturing

Graphene has numerous potential applications in ultrathin electronics. There an electrode should function in contact with fluids and under mechanical stress; therefore, its stability is specifically of concern. Here, we explored a custom-made quartz crystal microbalance (QCM) sensor covered with wet-transferred large-scale monolayer graphene for investigation of an electrode behavior. Monolayer graphene was found to be stable on an oscillating substrate in contact with air and liquid. Under the liquid flow and simultaneously applied electrochemical potential, we managed to induce graphene oxidation, impact of which was observed on a quartz crystal microbalance monitoring and Raman spectra. Applied potentials of 1 V and higher (vs. Ag/AgCl reference electrode) caused graphene oxidation which led to loss of the layer integrity and erosion of the material.