Fig. 2: XPS measurements.

High-resolution XPS spectra of (a) Ni 2p, (b) Fe 2p, (c) C 1 s, and (d) O 1 s for NiFe-LDH@cp and SU-NiFe-LDH(TA)@cp electrodes.
High-resolution XPS spectra of (a) Ni 2p, (b) Fe 2p, (c) C 1 s, and (d) O 1 s for NiFe-LDH@cp and SU-NiFe-LDH(TA)@cp electrodes.