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

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 (Epc) 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.