<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Pure Cu<sub>2</sub>Mo<sub>6</sub>S<sub>8</sub> nanocubes are prepared from a mixture of (NH<sub>4</sub>)<sub>2</sub>MoS<sub>4</sub>, CuCl<sub>2</sub>, and graphene in DMF (Ar, 90 °C, 4 h) followed by heating in reducing atmosphere (flowing 4% H<sub>2</sub>/Ar, 1000 °C, 7 h).</p> </abstract>