Cow Dung Derived PdNPs@WO3 Porous Carbon Nanodiscs as Trifunctional Catalysts for Design of Zinc–Air Batteries and Overall Water Splitting

The main motif of this work is to fabricate a highly efficient, economic, nanodisc shaped trifunctional electrocatalyst using a tungsten trioxide modified carbon nanosheet decorated with palladium nanoparticles. The beauty of this work is that a special carbon precursor is used for the synthesis of the electrocatalyst, a waste material, i.e., cow dung. The performance of the cow dung derived nanodisc electrocatalyst (Pd@WO3-NDs) toward oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) is compared with three other electrocatalysts (derived from graphene oxide, chitosan, and graphite carbon sources) also, and it is found that Pd@WO3-NDs show superior performance over that of the other three. The electrocatalyst exhibits the lowest onset potential (1.32 V vs NHEs), highest current density (492 mA cm–2), lowest overpotential (113 mV), and lowest Tafel slope (62.8 mV dec–1) for OER; an onset potential of 1.02 V, overpotential of 195.0 mV, and Tafel slope of...