Fig. 4: Theoretical investigations.

Computational models and localized electric field distributions of a p-Ni(OH)2, b Ov-Ni(OH)2, c BDC-Ni(OH)2, and d Ov-BDC-Ni(OH)2. The pink, red, brown, and green spheres represent H, O, C, and Ni, respectively. e Free energy diagram for O2 to HO2- at 0.7 V. f Calculated energy barriers for all models of 2e- ORR with the final product as HO2-. g Calculated energy diagram for 2-electron and 4-electron ORRs of BDC-Ni(OH)2. Source data for Fig. 4e–g are provided as a Source Data file.