Fig. 3: Enhanced stability by the flexible structure.
From: Enhanced oxygen evolution over dual corner-shared cobalt tetrahedra
a HRTEM images of surface structures from the as-prepared YBC4 and 1000-cycled YBC4. b The XRD patterns of the as-prepared YBC4 powder, electrode substrate of graphite paper (gp), and YBC4@gp before and after 1000 cycles of CV cycling. c The details of peak shifts in the XRD patterns of YBC4@gp before and after CV cycling. d An oxygen intercalation process in the YBC4 lattice. The sky-blue spheres and green spheres represent oxygen atoms inserted into the lattice. e Measured Co K-edge XANES of the as-prepared and electrochemically oxidized YBC4. f k3-weighted Co K-edge EXAFS spectra of the as-prepared and electrochemically oxidized YBC4. g The Co-O distance, the mean coordination number of Co, and oxygen nonstoichiometry (δ) in the as-prepared and the thermally/electrochemically treated YBC4. The inset shows the error bar (SD) for the data. The oxygen nonstoichiometry is estimated based on the mean coordination number from a YBaCo4O7 and YBaCo4O834. The average coordination number in YBaCo4O7 and YBaCo4O8 is 4 and 4.44, respectively.
