Fig. 3
From: Unusual synergistic effect in layered Ruddlesden−Popper oxide enables ultrafast hydrogen evolution
DFT calculations. a Top view of the SrO-terminated Sr2RuO4 (001) surface. The RuO6 octahedra are alternately tilted with respect to the c-axis, and rotated in the ab plane as indicated by the curved arrows. b Free-energy diagram for hydrogen adsorption at the metal and oxygen sites on Sr2RuO4, SrRuO3, RuO2, Ru, and Pt. c Relationship between ΔGH*@O and d-band center as well as Ru−O bond length. Energy diagram and the simplified surface structures of the various reaction species along the Volmer−Heyrovsky pathway for HER in alkaline media on the d RuO2-terminated surface of SrRuO3 and e SrO-terminated surface of Sr2RuO4 at electrode potential U = 0 V and USHE = 0.83 V, respectively. TS transition state. The gray, green, orange/red, and light gray spheres represent Ru, Sr, O, and H atoms, respectively
