Effects of Capping Agents on Shape, Stability, and Oxygen Evolution Reaction Activity of Copper Nanoparticles

Abstract

Here, five different capping agents’ polyethylene glycol (PEG), cetyltrimethylammonium bromide (CTAB), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and oleylamine (OAm) are used to form copper nanoparticles (Cu-NPs), along with their electrocatalytic oxygen evolution reaction (OER) properties. The produced Cu-NPs’ mono-dispersity and their interactions with PEG, CTAB, PVA, PVP, and OAm were examined. The mean particle size determined by TEM images for the uncapped Cu-NPs as generated, PVA-capped, PVP-capped, CTAB-capped, PEG-capped, and OAm-capped samples, respectively, were 2.71 nm, 2.22 nm, 3.10 nm, 3.31 nm, 1.49 nm, and 1.71 nm. Greater than prepared catalysts, commercial Pt/C has a 3.7 nm size. It’s interesting to note that the CTAB-capped Cu-NPs considerably exhibit the strongest OER activity, with a very low overpotential of 222 mV at 10 mA cm−2, lower than many previously reported and the high electrocatalytic activity for OER of the commercial RuO2 catalysts. However, an expedited stress experiment shows that the CTAB-capped NPs have greater structural stability during electrochemical cycling. Their strong capping tendency and particle shape are the key causes of this. The approach for creating Cu nanocatalysts described in this paper has several potential uses for the creation of bimetallic catalysts.