Structural and electrochemical characteristics of hypo-hyper d-electrocatalytic materials aimed for preparation of electrodes for hydrogen evolution were studied. The basic catalytic material was prepared of 10% amorphous Co (grain size < 2 nm), 18% amorphous TiO2 and Vulcan XC-72, by sol-gel procedure. A number of modifications were applied aimed at improving the materials performances: (i) TiO2 was transformed into anatase by heating at 480 degrees C for 1 h, (ii) multiwalled carbon nanotubes (MWCNT) were used as a catalyst support instead of Vulcan XC-72 and (iii) Mo was added to Co phase in a quantity of 25 at.% (Mo:Co = 1:3). Both, material's intrinsic catalytic activity and surface area were affected by these modifications. As a result, the electrocatalytic activity for hydrogen evolution was improved, e.g. transformation of TiO2 into anatase form lowers the HER overpotential (eta) for 15 mV at 60 mA cm(-2). Introduction of MWCNTs lowered eta for 30 mV, while addition of Mo to metallic phase for 40 mV. The complete modification of all three catalyst's components (10% MoCo3 + 18% anatase + MWCNTs) was the most effective with 60 mV decrease of overpotential. Characterization was made by XRD, SEM, IR and XPS methods. Surface area was, measured by means of cyclic voltammetry. (c) 2007 Elsevier Ltd. All rights reserved.