Figure reports the plan-view transmission electron microscopy (TEM) image of as-deposited 2 nm TiO x /2 nm NiFe alloy films on the Cu TEM support with ultrathin carbon film (3-5 nm) under the same fabrication conditions of photoanodes. The top films homogeneously cover the entire surface of the Cu support, with some curved structures randomly distributed on the surface. No appreciable aggravated nanoparticles or voids appear on the plane-view TEM image of the TiO x /NiFe alloy films. Electron energy-loss spectroscopy (EELS) mapping details elemental plan-view distribution in the conformal coating of the NiFe alloy layer and the curved structure of the TiO x layer (Fig. ). The EELS spectrum in Fig. confirms the elemental composition of Ni, Fe, Ti, and O in the deposited TiO x /NiFe alloy film. We acquire high-resolution plan-view TEM images to visualize the atomic and crystalline structures of pristine TiO x /NiFe alloy film. Figure shows the continuous layers of nanocrystals, ranging from 1.65 nm to 8.24 nm in lateral size, surrounded by amorphous regions. The lattice fringes with an interplanar distance of 0.209 nm and 0.178 nm correspond to the (111) and (200) planes of NiFe alloy, respectively . The fast Fourier transform (Fig. , inset) shows the far-field circular ring patterns corresponding to the (111), (200), (220) planes of NiFe alloy with blurred background, visualizing the hybridized nanocrystalline grain and amorphous nano-domain features of the surface layer.