Cadmium Sulfide Embedded Prussian Blue as Highly Active Bifunctional Electrocatalyst for Water-Splitting Process

Abstract

Process of water-splitting to produce hydrogen has limited application at commercialscale. As substantial overpotential is required at anode for the Oxygen Evolution Reaction (OER) and at cathode for the Hydrogen Evolution Reaction (HER). CdS as semiconductor possess remarkable chemical stability for redox reactions, high absorption capacity, diverse morphologies, and negative conduction band edge. Photo and electrocatalytic applications of CdS and its hybrids include low cost and green water-splitting for H2 generation. We present an interface engineering strategy for constructing an effective bifunctional electrode material for the water splitting process by using CdS-NRs@PBNPs heterostructures. These bifunctional electrocatalyst have demonstrated improved water splitting performance, for both HER and OER processes. For HER, the optimized hybrid CdSNRs@PBNPs (1:1) shows significantly improved catalytic performance with low overpotentials of 126 mV and 181 mV, respectively, at current densities of 10 mA.cm-2 and 20 mA.cm-2 . Similarly, for OER it displays an overpotential of 250 mV and 316 mV at current densities of 10 mA.cm-2 and 20 mA.cm-2 . Furthermore, the CdSNRs@PBNPs(1:1) has demonstrated long-standing stability of 20 hours. The hybrid's enhanced OER and HER activity is attributable to a synergetic impact between CdSNRs and PBNPs, as well as the active site modification due to the presence of Cadmium and iron in the hybrid