In-situ generated of interface nanoengineering to improve bifunctional electrocatalysts activity

Abstract

The exploitation of efficient electrocatalysts is vital for zinc-air batteries (ZABs). Fe-based catalysts exhibit insufficient bifunctional activity and stability, impeding the further development of ZABs. Herein, an efficient bifunctional electrocatalyst (PFeNC@NiFe-LDH) is rationally constructed and designed through the pore-creating and in-situ-generated interface nanoengineering approach. In this process, in-situ Fe-modified framework material (Fe-ZIF-8) regulates intermetallic distance to prevent Fe atom agglomeration. Fe-ZIF-8 and activator are co-heated to enable a highly porous structure and single-atom catalyst (PFeNC). The porous defect sites in PFeNC can be served as nucleation centers to anchor NiFe-LDH nanosheet, reinforcing the stability of the complex and enhancing bifunctional catalytic activity. Benefiting from single-atoms dispersing, interface effect, hierarchical pore channel, and synergistic effect, the PFeNC@NiFe-LDH demonstrates eminent bifunctional oxygen electrocatalytic performance (ΔE = 0.66 V), high stability, and rapid kinetic process (73.1 mV dec-1) for oxygen reduction reaction(ORR)), far outperforming the commercial Pt/C + IrO2 benchmark (ΔE = 0.87 V). Furthermore, the PFeNC@NiFe-LDH as a ZABs air-electrode delivers prominent stability last 16 days. These results take a perspective to devise bifunctional composite catalysts with NiFe-LDH grown on carbon-based materials.