Single Crystals of α-MoO3-Intercalated {Ni(H2O)6}2+ and Electrocatalytic Water Reduction: Toward a Class of Molybdenum Bronzes.

Abstract

We have successfully intercalated {NiII(H2O)6}2+ into the α-MoO3 layer, leading to the isolation of green single crystals of [MoVI2O6(CH3COO){NiII(H2O)6}0.5]·H2O (1). The homogeneous electrochemistry of 1 in its aqueous solution exhibits electrocatalytic hydrogen evolution reaction (HER) with concomitant electrochemical deposition of [HMo3VIMoVO12(CH3COO){NiII(H2O)5(OH)}] (2). Compound 2, a new molybdenum bronze, acts as an efficient and stable heterogeneous electrocatalyst for water reduction to molecular hydrogen. This work represents the first paradigm of a molybdenum bronze intercalating a transition metal-aqua ion.