| Abstract [eng] |
The aim of this work was to investigate the influence of amino acids on the activity and stability of hydrothermally synthesized molybdenum disulfide (MoS2) electrodes for the hydrogen evolution reaction, and to determine the nature of the most effective MoS2 active positions. The influence of amino acids on the hydrothermal synthesis of molybdenum disulfide was established for the first time. It was shown that the addition of glycine, cysteine or histidine amino acids to a solution of ammonium heptamolybdate and thiourea resulted in the hydrothermal synthesis of a nanoplatelet MoS2 coating with a relatively large amount of the metastable, metallic 1T-MoS2 phase. The increase in this metallic phase is attributed to the formation of amino acid fragments during the reaction, which intercalate into the molybdenum disulfide interlayers, stabilizing the metastable 1T-MoS2 phase. Due to a relatively high content of 1T-MoS2 phase, molybdenum sulfide electrodes with amino acids possess higher activity of hydrogen evolution reaction. A new method of increasing the activity of molybdenum disulfide electrodes by anodic pretreatment of synthesized MoS2 coatings has been investigated. It is shown that anodic pretreatment increases the relative amount of catalytically active bridging S22- groups, which are considered as the active positions for hydrogen evolution reaction. By treating MoS2 with a short anodic pulse, the activity of the electrode can be increased up to 30%. |
