Ni-Co-Se nanoparticles modified reduced graphene oxide nanoflakes, an advance electrocatalyst for highly efficient hydrogen evolution reaction

The present manuscript reports a simple one-step wet chemical approach to synthesis reduced graphene oxide nanoflakes (RGONF) from graphite by a thermal reduction at low temperature. The optical, Fourier Transform Infrared, X-ray diffraction, Raman, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and transmission electron microscopy are used to demonstrate the synthesis RGONF. This method is simple and avoids the usage of harmful chemical reductants. Then, Ni-Co-Se nanoparticles were solvothermal deposited on RGONF in aqueous media (RGONF/Ni-Co-Se) with an average size of 80 nm. Then, a glassy carbon electrode (GCE) was modified with RGONF/Ni-Co-Se and is used as an electrocatalyst for hydrogen evolution reaction (HER) in 0.50 mol L-1 sulfuric acid. The results showed an excellent catalytic activity of RGONF/Ni-Co-Se with an overpotential of 5 mV (vs. RHE) to achieve high current densities of 600 mA.cm-2 (at -780.0 mV). As well, the applied overpotential and slope for HER is better than expensive Pt/C (20%) catalyst, which used in fuel cells[1]. Also, the Tafel slope was about 30±3 mV decade-1 and suggested the Tafel mechanism for HER. ;