Abstract
Developing two-dimensional (2D) and single atomic layered materials is a fascinating challenge. Here we successfully synthesize porphyrin-based monoatomic layer (PML), a freestanding 2D porphyrin-based material of monomer-unit thickness (2.8 angstrom). The solvothermal method provides a bottom-up approach for tailoring the monoatomic layer from the nanoscale to the milliscale. PMLs containing accurately tailorable M-N(4)units (M=Cu and Au) were synthesized, which present metal center-dependent performance for CO(2)electrocatalysis. PML with Cu-N(4)centers performs high faradaic efficiencies of HCOO(-)and CH4(80.86 % and 11.51 % at -0.7 V, respectively) while PML with Au-N(4)centers generates HCOO(-)and CO as major products (40.90 % and 34.40 % at -0.8 V, respectively). Irreversible restructuring behavior of Cu sites is also observed. Based on the graphene-like properties and metal center-selectivity relationships, we believe that PML will play a distinct role in various applications.