Iridium-doped ZIFs-derived porous carbon-coated IrCo alloy as competent bifunctional catalyst for overall water splitting in acid medium

Bifunctional electrocatalysts for overall water splitting in acidic media is critical for polymer electrolyte membrane (PEM) electrolysis of water. We report a synthesis of porous carbon-coated noble metal-based catalysts. We adopt simple annealing strategy involving Ir-doped zeolite imidazole skeleton to obtain IrCo alloys encapsulated by the porous carbon layers and carbon nanotubes , which is a new method for synthesizing IrCo alloy. The amount of Ir loaded in IrCo NPs catalyst is extremely low (only 6.7 wt%) and IrCo NPs exhibit excellent catalytic activity for both HER and OER in acidic environment, to achieve 10 mA cm −2 current density during HER and OER, overpotential of only 23.9 and 270 mV is required for our novel IrCo NPs catalyst. More significantly, IrCo NPs reach 10 mA cm −2 during overall water splitting at a cell voltage of only 1.55 V in 0.5 M H 2 SO 4 and demonstrated good durability. Thus, it has excellent prospects to be implemented into PEM for water electrolysis.