Oxidized Laser-Induced Graphene for Efficient Oxygen Electrocatalysis

An efficient metal-free catalyst is presented for oxygen evolution and reduction based on oxidized laser-induced graphene (LIG-O). The oxidation of LIG by O₂ plasma to form LIG-O boosts its performance in the oxygen evolution reaction (OER), exhibiting a low onset potential of 260 mV with a low Tafel slope of 49 mV dec^-1 , as well as an increased activity for the oxygen reduction reaction. Additionally, LIG-O shows unexpectedly high activity in catalyzing Li₂ O₂ decomposition in Li-O₂ batteries. The overpotential upon charging is decreased from 1.01 V in LIG to 0.63 V in LIG-O. The oxygen-containing groups make essential contributions, not only by providing the active sites, but also by facilitating the adsorption of OER intermediates and lowering the activation energy.