Synthesis of egg-shaped core@shell structured CuS@TiO2 particle and its thermal stability

Egg shaped particles formed with micro-CuS cores capsulated perfectly by TiO2 nano-porous shells were synthesized from 1, 2-ethylene glycol additive in ethanol using a sol–gel procedure. The optimal CuS:TiO2 molar ratio to obtain the egg shaped CuS core@TiO2 shell was 1:7. TEM revealed an egg shape composed of CuS core@TiO2 shell micro-particles with a size ranging from 200 to 400 nm. This paper proposes the mechanism of the formation of egg shaped and core-shell structured CuS@TiO2 particles based on the pathway of a bridge among Cu, 1, 2-ethylene glycol, and the Ti complex during crystal growth. The core CuS was covered completely by porous TiO2 and was quite stable at temperatures greater than 600 °C.