“…The GaS crystalline structure consists of double layers of gallium and sulfur with strong intralayer metal-metal bonds (S-Ga-Ga-S sheets) that are stacked along the c-axis via weak van der Waals forces. This combination gives rise to strongly anisotropic optical, electrical and mechanical properties, and makes GaS -which is a wide-bandgap semiconductor 6 -a promising candidate for assorted optoelectronic devices and sensors, e.g., nearblue light-emitting diodes 7 and¯eld-emission-based devices. 8,9 In addition, nanomaterials from layered metal sul¯des in general, and GaS in particular, can intercalate foreign atoms, yielding electrochemical properties that render them suitable for rechargeable secondary batteries.…”