In situ growth of SeOx films on the surface of Ni–Fe–selenide nanosheets as highly active and stable electrocatalysts for the oxygen evolution reactionElectronic supplementary information (ESI) available: Experimental section; SEM, TEM images, EDX, elemental weight percentage and SAED patterns of FeNi LDH and CM7-FeNi LDH; EDX and elemental weight percentage of CM7-FeNixSe and FeNixSe; XRD patterns of NiFe foam, CM7-NiFe foam, FeNi LDH and CM7-FeNi LDH; CVs of CM7-FeNixSe, FeNixSe, CM7-FeNi LDH, FeNi LDH, CM7-NiFe foam and pure NiFe foam; dependence of Δj on the scan rate at different double layer capacitances; elemental weight percentage of CD-CM7-FeNixSe and CM7-FeNixSe; high-resolution XPS spectra of Ni 2p, Fe 2p, Se 3d, and O 1s of CM7-FeNixSe and CD-CM7-FeNixSe; HER polarization curves, Nyquist plots (overpotential = 250 mV), and OER polarization curves of CMy-FeNixSe; SEM, TEM, HRTEM, SAED patterns, EDX, elemental weight percentage, and XRD patterns of CM1-FeNixSe, CM7-FeNixSe, and CM20-FeNixSe; high-resolution XPS spectra of Ni 2p, Fe 2p, Se 3d and O 1s of CM1-FeNixSe, CM7-FeNixSe and CM20-FeNixSe; OER catalytic activity comparison; and overall water splitting catalytic activity comparison. See DOI: 10.1039/d1ma01208h

In situ growth of SeOx films on the surface of Ni–Fe–selenide nanosheets as highly active and stable electrocatalysts for the oxygen evolution reactionElectronic supplementary information (ESI) available: Experimental section; SEM, TEM images, EDX, elemental weight percentage and SAED patterns of FeNi LDH and CM7-FeNi LDH; EDX and elemental weight percentage of CM7-FeNixSe and FeNixSe; XRD patterns of NiFe foam, CM7-NiFe foam, FeNi LDH and CM7-FeNi LDH; CVs of CM7-FeNixSe, FeNixSe, CM7-FeNi LDH, FeNi LDH, CM7-NiFe foam and pure NiFe foam; dependence of Δj on the scan rate at different double layer capacitances; elemental weight percentage of CD-CM7-FeNixSe and CM7-FeNixSe; high-resolution XPS spectra of Ni 2p, Fe 2p, Se 3d, and O 1s of CM7-FeNixSe and CD-CM7-FeNixSe; HER polarization curves, Nyquist plots (overpotential = 250 mV), and OER polarization curves of CMy-FeNixSe; SEM, TEM, HRTEM, SAED patterns, EDX, elemental weight percentage, and XRD patterns of CM1-FeNixSe, CM7-FeNixSe, and CM20-FeNixSe; high-resolution XPS spectra of Ni 2p, Fe 2p, Se 3d and O 1s of CM1-FeNixSe, CM7-FeNixSe and CM20-FeNixSe; OER catalytic activity comparison; and overall water splitting catalytic activity comparison. See DOI: 10.1039/d1ma01208h