Quasi-Fe-/Zn-phthalocyanine polymer derived 2D Fe[sbnd]N[sbnd]C single-atom catalyst for highly efficient ORR and H2O2 sensing

Abstract

A novel two-dimensional (2D) single-atom Fe/N/C catalyst (Fe1Zn30NCPDI) has been prepared upon pyrolyzing a well-designed quasi-Fe-/Zn-phthalocyanine-based polymer (qFePc1@qZnPc30@PDI). In the qFePc1@qZnPc30@PDI precursor, qFePc moieties containing Fe-N4 sites are efficiently segregated by lots of qZnPc moieties connected together by perylene linkers, which not only leads to the larger specific area in the resulting Fe1Zn30NCPDI but more importantly ensures the in-situ formation of Fe-N4 sites on the self-supporting 2D N-doped carbon backbone. Impressively, Fe1Zn30NCPDI exhibites its superior oxygen reduction reaction (ORR) electro-catalytic activity and peroxidase (POD)-like activity. For ORR in an alkaline medium, it exhibites a much higher onset potential of 0.97 V and half-wave potential of 0.89 V than 20 wt% Pt/C catalyst with good durability of 92 % retention rate after 20000 s. And, Fe1Zn30NCPDI also shows better peak power density (86 mW cm−2) compared with 20 wt% Pt/C in Zn-air battery. Benefiting from the specific POD-like activity of Fe-N4, the Fe1Zn30NCPDI also shows excellent and selective performance in colorimetric H2O2 sensing, with the ultrafast response (30 s), a low limit of detection (10 nM), and good robustness. This work sheds light on a promising design concept for synthesizing 2D polymer-derived single-atom multifunctional catalysts.