Metal-doped fullerene: promising electrocatalysts for hydrogen and oxygen evolution reactions†

Abstract

Exploring efficient electrocatalysts for the splitting of water to generate hydrogen and oxygen is essential for the development of renewable energy sources, especially considering the detrimental environmental impacts of fossil fuels. Single-atom catalysts (SACs) have emerged as highly promising candidates for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). A significant amount of research has been done on hetero atom-doped carbon-based SACs, such as graphene nanosheets, nanorods, and other carbon allotropes. However, the potential of fullerene, another allotrope of carbon, for electrocatalytic applications has not been extensively studied. In this work, we investigate transition metal (TM)-doped (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt) fullerene as an electrocatalyst for the HER and OER using density functional theory (DFT). The ab initio results show that sixth-row transition metals, such as Ir and Pt, exhibit excellent catalytic activity for the HER with ΔG_H values of 0.02 and 0.11 eV, respectively. The fifth-row transition metals, Ru and Pd, are identified as superior catalysts for the OER, with overpotential values of 0.48 and 0.51 V, respectively. The thermal stability of these promising catalysts is determined through ab initio molecular dynamics (AIMD) simulations. The excellent catalytic activity of TM-Ful systems for the HER and OER is explained through the charge of TM centers, the position of the band centers and the adsorption strength of the reaction intermediates. These results demonstrate the potential application of the new class of TM-doped fullerene systems as effective electrocatalysts for water splitting.