Nanokomposit kaolin-TiO2 dengan dopan urea untuk adsorpsi dan fotodegradasi zat warna biru metilena

Abstract

Methylene blue is one type of dyes found as pollutant in Indonesia water system. Kaolin-TiO2 nanocomposite was synthesized and used to overcome this problem by utilizing its adsorption-photodegradation mechanism. Kaolin-TiO2 nanocomposite was made by mixing kaolin powder and TiO2 powder physically using ball milling and paste methods. The ball milling method is found to be simpler than paste method, and also resulting in smaller particle size. Smaller particle size also found to increase both adsorption and photodegradation activities. It is believed that ball milling method also generated a homogenous mixture. From 2 different sample compositions and 3 milling times used, it was found that synthesis kaolin-TiO2 nanocomposite requiring calciumbased binder with an optimum milling time of 5 hours. Kaolin-TiO2 nanocomposite was doped with urea by manual physical mixing followed by calsination at 300 °C for 2 hours. Urea doped-nanocomposite has larger activity than undoped nanocomposite in visible light zone. It means that the photocatalytic activity of urea doped-nanocomposite was successfully shifted to the red zone area of the visible light. Therefore, incident sunlight can be used as energy source in the adsorption-photodegradation process using nanocomposite Kaolin-TiO2.