▎ 摘　　要

A nanohybrid of Pt nanoparticles and reduced graphene oxide (Pt/rGO) is prepared and exploited for hydrogen evolution reaction (HER) in acidic medium. At first, glassy carbon electrode (GCE) is modified by graphene oxide (GO) nanosheets. Then, during the electrochemical reduction, GO film is converted to rGO. Finally, rGO/GCE is immersed in acidic solution of mM K2PtCl6 for 20min and then with scanning the potential of electrode from 0.00 to -0.20V vs. NHE, Pt (IV) ions are reduced to Pt. Characterization of Pt/rGO nanohybrid is achieved by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy. FESEM images confirm that on the surface of rGO film, Pt nanoparticles with size in the range of 5-15nm are formed. Electrochemical experiments reveal that Pt/RGO/GCE exhibits a small onset potential of -0.03V vs. NHE and Tafel slope of about 33mVdec(-1) for HER. Pt/rGO/GCE has higher electrocatalytic activity for HER than rGO/GCE and Pt/GCE. In addition, the nanohybrid presents an enhanced catalytic activity towards HER than bare Pt electrode. It is observed that the current density of HER at the Pt/rGO nanohybrid shows a little decrease after 1000 continuous potential cycles which means the good stability of the catalyst. In addition, chronoamperometric studies show that Pt/rGO/GCE exhibits a noticeable stability for HER. The obtained results allege that Pt/rGO nanohybrid can surmount the overvoltage of HER and can be used as promising electrocatalyst in HER in acidic medium.