XPS study of NiO thin films obtained by chemical vapor deposition

Nickel oxide (NiO) thin films are of great importance for a variety of technological applications, especially in (photo)electrocatalysis for clean energy production and pollutant degradation. In this field, various research efforts are devoted to the preparation of thin films with controllable chemicophysical properties. In the framework of our research activities, we have recently fabricated NiO thin films by means of chemical vapor deposition (CVD) using a series of closely related Ni(II) β-diketonate-diamine molecular precursors. In the present work, the attention is focused on the x-ray photoelectron spectroscopy (XPS) analysis of a representative NiO film grown at 400 °C in an O2 + H2O reaction atmosphere. Besides the wide scan spectrum, high resolution spectra for C 1s, O 1s, and, in particular, Ni 2p are reported and discussed in detail.