This work presents a research on the preparation of thin composite catalytic films in which an essential part of the efficient but expensive Ir is substituted by Au sub-layer using the preparation method of direct current magnetron sputtering (DCMS). The aim is to investigate the influence of the Au sub-layer on the catalytic activity toward oxygen evolution reaction (OER) of water electrolysis. The properties of the sputtered films are studied using X-ray diffraction (XRD) and electrochemical methods of cyclic voltammetry, quasi steady state polarization and chronoamperometry. It is found that by proper variations in the films thickness it is possible to realize synergetic effects leading to essential decrease in Ir loading and the cost of catalysis without sacrifice in efficiency. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.