Laser Modification of Graphene Oxide for Efficient Oxygen Evolution Reaction

The Oxygen Evolution Reaction (OER) is the bottleneck in the water splitting reaction since it involves four intermediate steps, constituting the adsorption–desorption of oxygen-based radical groups, and not all of them are energetically favorable. Rapidly growing research interest is focusing on carbon-based materials as novel, highly active and durable non-precious electrocatalysts for the OER, representing a valuable alternative to precious and rare materials with electrochemical properties tuned by defect creation. In this work, we propose a facile and green methodology based on the modification of graphene oxide by laser irradiation to obtain an alternative OER catalyst. GO flakes were chemically and physically modified using pulsed laser irradiation at 532nm with fluences of 1.5J/cm2 and 2.5J/cm2. Different analyses were carried out to correlate the electrochemical performance with the structural, optical, and morphological properties; after that, we correlated the improvements in the OER with respect to the pristine GO with the increase in OH functional groups obtained by laser treatment. The best-performing sample exhibited an overpotential of 380mV, comparable to that of catalysts reported in the literature but with the advantage of not being a precious or rare material.