Highly Efficient Electrocatalyst for Oxygen Evolution Reaction: DFT Investigation on Transition Metal‐Tetracyanoquinodimethane Monolayer

Abstract

AbstractTo search for efficient electrocatalyst towards oxygen evolution reaction (OER) for sustainable energy production, a family of transition metal‐tetracyanoquinodimethane (TM‐TCNQ) (TM=Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd)monolayers have been studied by first principle based density functional theory (DFT) computations. The systematic investigations on various TM‐TCNQ structures revealed that Ni‐TCNQ monolayer exhibits best catalytic activity towards OER. At equilibrium potential (1.23 Vvs RHE), the free energy profile of Ni‐TCNQ monolayer for different reaction intermediates is not completely downhill which points out that water could not be oxidized by the photo‐generated holes at that potential. However, at and above 1.71 V, all the OER reaction steps on Ni‐TCNQ surface is found to be thermodynamically downhill, measuring a low onset overpotential, ca. 0.48 V in acidic media (pH=0). The estimated overpotential for other TM‐TCNQ structures are comparatively higher to promote energy‐efficient OER activity. The excellent performance of Ni‐TCNQ monolayer as OER catalyst were explained in terms of volcano plot, scaling diagram, d‐ band centre model, band structure and charge analysis.