Morphological control in solvothermal synthesis of copper sulphides on copper foil

Copper sulphides Cu9S5 and polymorphs of Cu2S were synthesized apparently for the first time on copper foil through its solvothermal reaction with sulphur (the former being used both as substrate and reactant), with 75% fill of the autoclave with water, ethanol or ethylenediamine as solvents. Water as solvent produced micron-sized hemispheres of Cu9S5 (composed of much smaller particles of size ∼5–6 nm), truncated by forming interfaces and exhibiting relatively large dihedral angles (80–120°). Ethanol produced fibre-like or thread-like (∼40 nm diameter) morphological form of Cu9S5, generally woven into network-structures. Ethylenediamine, which produced Cu2S (monoclinic), as also β-Cu2S (hexagonal), assisted formation of hexagonal micron-sized single crystal rods with a hexagonal end face in conjunction with β-Cu2S.