Efficient Electrochemical Water Oxidation to Hydrogen Peroxide over Intrinsic Carbon Defect-Rich Carbon Nanofibers

Two-electron water oxidation reaction (2e--WOR) provides a promising route to produce hydrogen peroxide (H2O2) from water, but it is currently hampered by low H2O2 partial current. Here, the intrinsic carbon defects-rich carbon nanofibers are demonstrated to be highly effective for electrochemical 2e--water oxidation. A H2O2 current density of 72.6 mA cm-2 is achieved at 2.9 V vs RHE which among the highest values reported for 2e--WOR. XPS and NEXAFS studies indicate pentagonal and octagonal ring defects are dominant in optimal sample. A combination of DFT calculation and methanol competitive oxidation experiment reveals ring defects effectively reduce the adsorption strength of OH*, which ultimately promotes 2e--WOR for valuable H2O2 production. Our study makes a helpful attempt in exploring carbon-based materials for efficient 2e--WOR electrocatalysts.