| Abstract [eng] |
This thesis covers electrochemical synthesis, structure and morphology analysis of Co-Mo-O-S films. In addition, their electrocatalytic activity in hydrogen evolution reaction was investigated. Films deposition mechanism was investigated using cyclic voltammetry and linear voltammetry methods. Forming mechanism of films on electrically conductive glass plates was discussed. Cobalt(II) chloride, tetraammonium heptamolybdate, thiourea and ammonia in aqueous solutions were used as films precursors. Films were deposited using potentiodynamic method, electrically conductive glass plates were polarized from -1.2 to 0.2 V. It was determined that amount of the film depends on number of deposition sweep cycles. X-ray diffraction analysis showed that deposited films are of amorphous nature. SEM-EDS analysis revealed that Mo-O-S films are flat, but fractured, Co-O-S films are porous and Co-Mo-O-S films have nanostructured aggregates on its surface. Elemental composition of films was performed using EDS method. A significant portion of atoms in all the films is oxygen (over 65 at. %), while 2-3 at. % of sulfur were inserted. After investigating activity of films in hydrogen evolution reaction in phosphate buffer it was determined that the most active film was Co-O-S, but it had relatively low stability. Addition of molybdenum had positive effect on film stability, but negative effect on its catalytic activity. |
