A nitrogen- and sulfur-rich conductive polymer for electrocatalytic evolution of hydrogen in acidic electrolytes

A conductive polymer, poly(2-amino-5-mercapto-1,3,4-thiadiazole) (PAMT), was electrodeposited on a glassy carbon substrate for electrocatalyzing hydrogen evolution reaction (HER) in H2SO4 electrolytes. The prepared material was characterized by scanning electron microscope and X-ray photoelectron spectroscopy. The surface of the PAMT film was uniform, crack-free, and was full of curly short filaments (<100 nm long). The free active sites of the PAMT for HER could be represented as –N, which exist in pairs meeting the dual-site requirements for H–H combination. The Tafel analysis revealed that the open circuit potential was positively shifted by 313 mV due to the PAMT catalyst, with a prominent decrease in activation energy. Both the electrochemical impedance spectroscopy and chronopotentiometry suggested that the PAMT can not only significantly reduce the charge transfer resistance of the HER, but also facilitate the desorption of the generated hydrogen from the active sites. These results indicate that the N- and S-rich conductive polymers deserve further investigation as potential electrocatalyst candidates for hydrogen energy production.