Diiron azadithiolate clusters supported on carbon nanotubes for efficient electrocatalytic proton reduction

Abstract

Herein, we report the synthesis of a new diiron azadithiolate compound {(μ-SCH₂)₂N(C₆H₄CH₂CH₂OH-4)}Fe₂(CO)₆ (1) and especially its covalent attachment onto benzoxy-functionalized single-walled carbon nanotubes (f-SWCNTs) to construct the first example of diiron azadithiolate clusters supported on carbon nanotubes (1-f-SWCNTs) for efficient electrocatalytic proton reduction to H₂ in an aqueous medium. The structure and morphology of the as-prepared hybrid 1-f-SWCNTs have been well characterized by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Notably, the 1-f-SWCNT hybrid absorbed on the cheap glassy carbon electrode exhibits a much more positive reduction potential (E_pc) in pure water relative to an organic solvent (MeCN) and an outstanding turnover frequency (TOF) of 9444 s⁻¹ for H₂ production in the presence of 0.2 N aqueous H₂SO₄ as a proton source under electrochemical conditions.