A porous heterostructure catalyst for oxygen evolution: synergy between IrP2 nanocrystals and ultrathin P,N-codoped carbon nanosheets

Abstract

Designing efficient and robust oxygen evolution reaction (OER) electrocatalysts is of great importance for various electrochemical energy storage and conversion applications. Herein, we developed IrP2 nanocrystals uniformly anchored in P,N-codoped carbon nanosheets (IrP2@PNC-NS) as highly active OER electrocatalysts. The ultrathin PNC-NS reconstructs an agaric-like porous structure, which can inhibit the agglomeration of the IrP2 nanocrystals effectively. Moreover, the in-situ phosphatization leads to the formation of a strong electron interaction between PNC-NS and IrP2 nanocrystals, endowing the heterostructure materials with satisfying synergistic effects. Benefiting from the collaborative advantages of ideal configuration structure and favorable synergistic effects, IrP2@PNC-NS exhibits excellent OER performance with a low overpotential of 221 mV at 10 mA cm−2, and a small Tafel slope of 37.5 mV dec−1. DFT calculations reveal that the synergistic effects derived from the IrP2/PNC interfaces, which can effectively tune the activation barriers towards facilitating the oxygen evolution process. This work provides new insight into the design of heterostructure materials for advanced OER electrocatalysts.