Hydrothermal synthesis of tobermorite nanowires from porcelain stone

A facile and efficient hydrothermal process was explored to obtain tobermorite nanowires using porcelain stone and CaO powders as raw materials. The as-synthesised nanowires have a diameter of 50-100 nm and a length of tens of micrometres under conditions of a porcelain stone/CaO weight ratio of 3, a water/solid weight ratio of 22, a reaction temperature of 240°C and a reaction time of 24 h. The results indicate that the weight ratio of porcelain stone/CaO and hydrothermal temperature play important roles regarding the morphology and structure of tobermorite. Furthermore, a possible growth mechanism of the tobermorite nanowires is proposed. This approach might open up a simple and economic route to prepare tobermorite nanowires using inexpensive porcelain stone as the silicon source.