Highly dispersed Pd nanoparticles on NiO–CuO nanocomposite for efficient ethanol sensing

Abstract

Uniform dispersion of Pd nanostructures supported on hydrothermally synthesized bimetal oxides on Ni foam substrate was successfully achieved by a simple electrochemical approach. The incorporated metal oxides provide excellent support and active surface area, which lead to superior electro-catalytic performance towards ethanol sensing applications. The synthesized nanocomposite materials were characterized by XRD, FE-SEM, HR-TEM, and EIS techniques, and their electrochemical behaviour was investigated using cyclic voltammetry and chronoamperometry techniques. The proposed sensor demonstrated excellent catalytic activity, high reproducibility, and long-term stability for ethanol electro-oxidation. In addition, the fabricated sensor displayed high sensitivity of 1277 μA mM⁻¹ cm⁻² in the concentration range from 0.1 to 2.1 mM with a limit of detection 0.7 μM. Enhancement in electro-catalytic activity is mainly due to the induced synergistic effect of metal oxide nanocomposite support that stabilizes the Pd NPs through the Pd–HO bond by the transfer of an electron to the PdNPs. This study paves the way for designing and constructing effective electro-catalysts that can be used in the real-time analysis of alcohol sensing.