Catalysis of hydrogen evolution reaction by nanocomposite electrodes composed of copper nanoparticles based on carbon quantum dots as highly efficient electrocatalyst

Abstract

This study reports the synthesis, characterization, and electrochemical behavior of new non-platinum Cu-NPs/RCQDs/GCE nanocomposite. By investigating scanning electron microscopy images (SEM), the proposed and introduced nanocomposite shows spheres with an average size of less than 50 nm homogeneously dispersed on reduced carbon quantum dots (RCQDs) as an upper layer on glassy carbon electrode (GCE). Transmission electron microscopy image (TEM) of synthesized CQDs showed the small size of CQDs that was less than 20 nm. X-ray diffraction analysis (XRD) was used to investigate the crystallographic structures of electrodes. Also, the electrocatalytic treatment of catalysts toward hydrogen evolution reaction (HER) was studied in acidic media by some electrochemical techniques consisting of linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). Results show that Cu-NPs/RCQDs/GCE nanocomposite with lower onset potential relative to Cu-NPs/GCE is a better electrocatalyst for reaction catalysis. Also, this proposed catalyst showed high stability and conductivity at special faradaic voltage.