Biosynthesis of ZnO Nanosheets Decorated with Pd Nanoparticles and Their Application for Electrochemical Investigation of Ethanol

Hierarchical ZnO microflowers with sheet thickness of ≈ 23 nm were prepared in the presence of Cystoceira baccata algae extract. Pd nanoparticles with an average size of 4.9 nm were embedded on the surface of these nanosheets in the presence of Cystoceira baccata algae extract. The structure of ZnO@Pd was characterized by XRD, FESEM, high-resolution transmission electron microscopy, and energy-dispersive X-ray spectroscopy methods. To investigate the possible application of the synthesized nanoparticles, the electrooxidation of ethanol on the surface of ZnO@Pd modified carbon paste electrode in alkaline media was studied using cyclic voltammetry. The electrode showed high catalytic activity for ethanol oxidation. It also showed high selectivity toward ethanol in comparison to other alcohols. Chronoamperometric measurements showed that this electrode could be used as a probe for determination of ethanol in a relatively wide linear range (180–500 mM) with a low detection limit (60 μM). Graphical Abstract