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

The present manuscript reports a simple one-step wet chemical approach to synthesis reducedgraphene oxide nanoflakes (RGONF) from graphite by a thermal reduction at low temperature.The optical, Fourier Transform Infrared, X-ray diffraction, Raman, X-ray photoelectronspectroscopy, electrochemical impedance spectroscopy and transmission electron microscopy areused to demonstrate the synthesis RGONF. This method is simple and avoids the usage ofharmful chemical reductants. Then, Ni-Co-Se nanoparticles were solvothermal deposited onRGONF in aqueous media (RGONF/Ni-Co-Se) with an average size of 80 nm. Then, a glassycarbon electrode (GCE) was modified with RGONF/Ni-Co-Se and is used as an electrocatalystfor hydrogen evolution reaction (HER) in 0.50 mol L-1 sulfuric acid. The results showed anexcellent catalytic activity of RGONF/Ni-Co-Se with an overpotential of 5 mV (vs. RHE) toachieve high current densities of 600 mA.cm-2 (at -780.0 mV). As well, the applied overpotentialand 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..

Keywords:

Reduced graphene oxide nanoflakes , Thermal reduction , Ni-Co-Se nanoparticles , Solvothermal deposition , Hydrogen evolution reaction