Fig. 5: Mechanistic analyses.

a, b Quasi in situ electrochemical XPS spectra, and c, d in situ electrochemical Raman spectra of Ni4Mo and Ni4Mo/TiO2 collected at the selected potentials in 0.1 M NaOH during the HOR. The potentials are iR-corrected.

a, b Quasi in situ electrochemical XPS spectra, and c, d in situ electrochemical Raman spectra of Ni4Mo and Ni4Mo/TiO2 collected at the selected potentials in 0.1 M NaOH during the HOR. The potentials are iR-corrected.