Fabrication of ORR/OER Electrocatalysts with simple one-step strategy from sustainable cornstalks

Here we report a simple efficient one-step strategy to fabricate Oxidation Reduction Reaction (ORR) or/and Oxygen Evolution Reaction (OER) electrocatalysts directly from agricultural cornstalks waste with hierarchical porous structures and massive active hydroxyl groups. CaCl2 and NH4Cl activators were utilized to corrode the cornstalks in order to create a mesopore N-doped hybrid structure that was sufficiently stable under the high-temperature pyrolysis process, which prevented neighboring aggregates of transition metals. The synergistic effect of N, B and Fe, Co within the hierarchical biochar structures guaranteed a favorable ORR activity of 0.848 V and OER activity of 393 mV for the CaCl2 sample, showed better stability than commercial Pt/C and IrO2 catalysts.