Fig. 1: Thermodynamically favored atom ordering.
From: Triangular-ordered Co atoms activate substrates for ampere-level durable hydrogen production
Schematic illustration of two types of structures: surface-supported Co (SS-Co) (a) and ordered Co (O-Co) atoms (b). In the SS-Co structure, Co atoms are randomly absorbed on the surface of VN support, whereas in the O-Co structure, Co atoms substitute V sites within the VN lattice. c Binding energy of SS-Co/VN and O-Co/VN configurations as a function of the number of Co atoms ranging from one to five (denoted as 1 O-Co, 2 O-Co, 3 O-Co, 4 O-Co, and 5 O-Co, respectively). The O-Co configuration shows lower binding energies than those of their SS-Co counterparts. Inset: the corresponding atomic structures of SS-Co/VN and O-Co/VN under various configurations. d Schematic illustrating the migration of Co atoms from the VN surface or lattice in the configurations of SS-Co1, LS-Co1, SS-Co3, and O-Co3. The blue and yellow balls represent V and Co atoms, respectively. e Calculated migration energy barriers for the configurations in (d), revealing that the O-Co3 motif exhibits the highest energy barrier with enhanced structural stability. Source data for the (c, e) are provided as a Source Data file.
