Highly efficient bifunctional catalyst with 2D MoN formed in situ synergy for OER and ORR based-on Co(II) doped Mo(IV)-Ni(II) supramolecular coordination polymer

Abstract

Developing non-precious metal oxygen electrocatalysts is of great significance for storage systems and energy conversion. Pyrolyzation of the bimetallic Mo(IV)-Ni(II) supramolecular coordination polymer (SCP) for the first time by simultaneously introducing Co(II) ion with Graphene Oxide (GO) as template leads to a new outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional electrocatalyst (GO-Co@MoNi) composed structurally by 2D MoN flake formed in situ and CoNi alloy supported on lamellar GO. The unique components, sheet architecture, and intermetallic synergy of the GO-Co@MoNi catalyst (η = 340 mV, E1/2 = 0.855V) endow it comparable electrocatalytic performance towards OER to the commercial RuO2 electrocatalysts (η = 320 mV) and superior performance towards ORR to Pt/C (E1/2 = 0.84 V) electrocatalyst. Density functional theory (DFT) calculation reveals the essential role of trimetallic synergy at an unprecedented “comfortable” 4 × 1e− electrons reaction pathway in the excellent ORR in GO-Co@MoNi. The current research opens a skillful design strategy and a rare catalytic mechanism for constructing new oxygen electrocatalysts, and the results show that the SCP-based materials have great potential in the electrochemical field in the future, especially for efficient bifunctional electrocatalysts.