UC Berkeley

This article reports a study of electrochemical cycling effects on hydrogen evolution catalytic activity of gold nanoparticles in sulfuric acid. We found that after cycling within the double layer regime, up to 0.64 V vs RHE, there is a dramatic effect on the HER activity of gold nanoparticles: 128 mV drop of the overpotential, a decrease of 23 mV/dec for the Tafel slope as well as a nearly twenty times increase of the turn-over frequency (TOF). This enhanced activity is tentatively assigned to the formation of stepped like structures by the consecutive electrochemical cycling in the double layer region.