Fig. 1: Synthesis strategy.

a Traditional synthesis method and b BCS-oxide transition strategy for HEOs. c SAXS patterns, d N2 sorption isotherms, e wide-angel XRD patterns, and f high-resolution XPS 1s spectra of SC-MHEO and P-HEO.

a Traditional synthesis method and b BCS-oxide transition strategy for HEOs. c SAXS patterns, d N2 sorption isotherms, e wide-angel XRD patterns, and f high-resolution XPS 1s spectra of SC-MHEO and P-HEO.