Fig. 7: DFT calculated reaction energies of the OER with charge difference maps of polymetallic Co-Ni-Ru-S-Se.

a The atomic process of OER on Co-Ni-Ru-S-Se. b–d Free energy diagrams for OER on the Co-Ni-S-Se, Co-Ru-S-Se, and Co-Ni-Ru-S-Se surface, respectively. e–g The corresponding charge density distribution plots of Co-Ni-S-Se, Co-Ru-S-Se, and Co-Ni-Ru-S-Se.