A 2D Nano-architecture (NPSMC@Ir-Ru@rGO) Derived from Graphene Enfolded Polyphosphazene Nanospheres Decorated Ir-Ru Metals (PZS@Ir-Ru@GO) towards Bifunctional Water Splitting

Chem Asian J. 2023 Dec 1;18(23):e202300718. doi: 10.1002/asia.202300718. Epub 2023 Nov 6.

Abstract

A leap-forward approach has been successfully devised to synthesize a novel hierarchical binary metal modified heteroatom doped 2D micro-/mesporous carbon-graphene nanostructure (NPSMC@Ir-Ru@rGO) for overall water splitting application. To investigate the role of decorating metals, different electrolcatalysts like NPSMC, NPSMC@rGO, NPSMC@Ir@rGO, and NPSMC@Ru@rGO were also synthesized and structural changes were compared and investigated by physiochemical techniques. All of the samples have shown electrocatalytic activities attributed to the presence of heteroatom (N, P, S) doped micro-/mesoporous carbonaceous matrix, amorphous carbon in the coexistence of graphitic lattice carbons, presence of active metal NPs (Ir and/-or Ru), an even distribution of active sites, and graphene 2D interconnected channels to promote electron transfer ability, respectively. However, the Ir-Ru metal codeped nanocatalyst (NPCMS@Ir-Ru@rGO) is proved to be an excellent electrocatalyst based on the synergistic role of Ir-Ru metals that necessitates the low overpotentials of 181 mV and 318 mV to convey a current density of 10 mA cm-2 towards the electroctalytic application of HER and OER, respectively. Furthermore, exhibiting the corresponding Tafel slopes (132 and 70 mV dec-1 ) in an alkaline medium. This work is anticipated to open up new avenues for the development of promising electrocatalysts based on active metals modified heteroatom doped carbon nanomaterials for energy applications.

Keywords: Bifunctional water splitting; Heteroatoms; Iridium-/ruthenium NPs; Polyphosphazene; Reduced Graphene.