Efficient hydrogen evolution electrocatalysis using nitrogen doped carbon dot decorated palladium copper nanocomposites in acid medium

Abstract

The development of high performance electrocatalysts is pivotal for electrocatalytic hydrogen evolution reaction (HER). In this work, a nitrogen doped carbon dot (NDCD) supported palladium copper nanoparticle composite (n-PdCu@NDCDs) was synthesized and effectively utilized as an electrocatalyst. The as-synthesized n-PdCu@NDCD composite was duly characterized by regular analytical techniques (HR-TEM, EDS, XPS, XRD, FT-IR, and Raman). Moreover, the electrocatalytic activity of n-PdCu@NDCDs was studied by linear sweep voltammetry (LSV), Tafel, and electrochemical impedance spectroscopy (EIS) measurements in 0.5 M aqueous H₂SO₄. The overpotential at high current density of n-PdCu@NDCDs was much lower than that of PdCu, NDCDs, and bare GC. The EIS studies showed that the charge transfer resistance of n-PdCu@NDCDs decreased from 1864 to 503.4 Ω cm⁻² on increasing the HER overpotentials, which confirmed the excellent conductivity and activity of the composite. Thus the present work confirms the utility of the n-PdCu@NDCD composite as an electrocatalyst for the HER.