Fig. 2: Synthesis and structural characterization.

a SEM of Ru/Ti4O7. b TEM and c AC-HRTEM images of Ru/Ti4O7. d, e The schematic atom structure and the corresponding simulated HAADF-STEM images of Ti4O7 and Ru in Ru/Ti4O7, respectively. f Crystal plane spacing of Ti4O7 and Ru. g Schematic diagram of interface contact between Ti4O7 and Ru. h EDS mapping of Ru, Ti, and O in Ru/Ti4O7, respectively. i XRD pattern of Ru/Ti4O7.