Periodic One-Dimensional Single-Atom Arrays

The orderly assembly of single atoms into highly periodic aggregates at the nanoscale is an intriguing but challenging process of high-precision atomic manufacturing. Here, we discover that an in-plane film surface shrinkage can induce molecular self-assembly to arrange single atoms with unconventional distribution, contributing them to periodic one-dimensional segregation on carbon stripes (one-dimensional single-atom arrays (SAA)). This originates from the fact that metal phthalocyanine (MPc) molecules gradually aggregate and melt to form a film under a thermal drive and the help of sodium chloride templates, accompanied by surface shrinkage, self-assembly, and deep carbonization. At the nanoscale, these periodic parallel arrays are formed due to MPc molecular interactions by π-π stacking. At the atomic scale, the single atoms are stabilized by the vertical phthalocyanine-derived multilayer graphene. This can significantly modify the electronic structure of the single-atom sites on the outermost graphene (e.g., Fe-based SAA), thus optimizing the adsorption energy of oxygen intermediates and resulting in a superior oxygen reduction reaction (ORR) performance concerning disordered single atoms. Our findings provide a general route for orderly single-atom manufacturing (e.g., Fe, Co, and Cu) and an understanding of the relationship between orderly allocation and catalytic performance.