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Structural and electrochemical characteristics of hypo-hyper d-electrocatalytic materials aimed for preparation of electrodes for hydrogen evolution were studied and modified in order to improve their performances. All studied materials were of general composition 10% Ni + 18% TiO 2 + C.All materials were prepared of amorphous or crystalline TiO 2 , crystalline Ni or NiCo (10-20 nm) and Vulcan XC-72, by sol-gel procedure. Both, material's intrinsic catalytic activity and surface area were affected by applied modifications. As a result, the electrocatalytic activity was improved, e.g. transformation of TiO 2 into anatase form lowers the HER overpotential for 60 mV. Introduction of MWCNTs was even more effective, lowering η for 120 mV. Co addition to metallic phase lowers η for utmost 195 mV.Combined modification of TiO 2 and carbon substrate lowers η for 145 mV, while the complete modification of all three catalyst's components was the most effective with 230 mV decrease of overpotential.

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 TiO 2 and Vulcan XC-72, by sol-gel procedure. A number of modifications were applied aimed at improving the materials performances: (i) TiO 2 was transformed into anatase by heating at 480 • 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 TiO 2 into anatase form lowers the HER overpotential (η) for 15 mV at 60 mA cm −2 . Introduction of MWCNTs lowered η for 30 mV, while addition of Mo to metallic phase for 40 mV.The complete modification of all three catalyst's components (10% MoCo 3 + 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.

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