Surface Electronic Modulation with Hetero-Single Atoms to Enhance Oxygen Evolution Catalysis

Abstract

Oxygen evolution catalysis plays a crucial role in the solar-to-fuel conversion for green energy applications. However, developing efficient and stable catalysts for the oxygen evolution catalysis remains a great challenge. Here, we successfully activate an inefficient oxygen evolution catalyst using a simple single atom tailoring strategy. The Rh element with its unfilled 4d⁸ electron configuration was selected to atomically implant into a Cu oxide matrix, which has a filled 3d¹⁰ electron configuration. The hetero-Rh single atom (SA) migration was achieved by dispersing Cu₂O nanocubes in a RhCl₃ aqueous solution, enabling an ion exchange process. The activated catalyst (Cu₂O-RhSA) exhibited significantly enhanced catalytic activity toward oxygen evolution in alkaline media, surpassing the performance of pristine Cu₂O nanocubes and commercial IrO₂. A theoretical study further confirmed that the migrated hetero-Rh SAs can tailor the interaction between the Cu and O sites, modulating the electron density distribution on the surface of Cu₂O, leading to a more favorable oxygen evolution process.

Keywords: electrochemistry; electronic modulation; energy conversion; oxygen evolution reaction; surface chemistry.