X-ray photoelectron spectroscopy (XPS) analysis of MoS 2 @NiFeCo-Mo(doped)-LDH, before and after long-term HER, OER and OWS electrocatalysis, was conducted to gain comprehensive understanding on the surface chemical composition and electronic properties of the catalysts. The results in Figures and show the full XPS spectrum of MoS 2 @NiFeCo-Mo(doped)-LDH. Figure confirms the presence of Ni, Fe, Co, Mo, S, and O in the catalyst. Furthermore, the high-resolution XPS spectra in Figures and S6 reveal the Ni, Fe, Co, and Mo valence states in MoS 2 @NiFeCo-Mo(doped)-LDH. In Figures , the deconvoluted Ni 2p spectrum shows peaks at 852.42 and 855.86 eV, while the Co 2p spectrum has peaks at 776.56 and 780.23 eV. The core-level Fe 2p spectrum exhibits peaks at 707.75 and 719.19 eV, along with two shakeup satellites, indicating the presence of Ni, Fe, and Co in both their elemental and oxidized states (Ni 2+ , Co 3+ , and Fe 3+ , respectively). After prolonged electrocatalysis, only minor shifts in the metal 2p peak positions towards lower binding energies were observed (Figure ). These small shifts indicate that the materials retain their structure and chemical state during electrocatalysis.