Tailor-made open porous 2D CoFe/SN-carbon with slightly weakened adsorption strength of ORR/OER intermediates as remarkable electrocatalysts toward zinc-air batteries

Abstract A novel and versatile ionothermal synthesis is cleverly proposed to derive two dimensional CoFe/SN-doping and tailor-made open porous carbon nanosheets by inorganic eutectic salts as layered templates. Impressively, as-synthetized open pore structure of CoFe/SN-carbon can be precisely tailored by eutectic salt-templates. 2D CoFe/SN-doping carbon nanosheets (CoFe/SN C) exhibit high specific surface area (1004 m2 g−1) and ultrahigh pore volume (1.54 cm3 g−1). As a result, the 2D CoFe/SN C with ultrahigh meso/macro-porous pore volume (1.25 cm3 g−1) exhibits superior catalytic activity for ORR (E1/2 = 0.843 V) and OER (Ei=10 = 1.504 V) in alkaline medium. Simultaneously, the assembled zinc-air batteries with open porous CoFe/SN C catalysts display high power density (169 mW cm-2) and outstanding stability (run stable for 5100 min). More importantly, density functional theory (DFT) calculation reveals that coupling of Fe-N4 and Co-N4 species can boost bifunctional catalytic activity originating from slightly weakened adsorption strength of ORR/OER intermediates on active sites.