Manganese Oxide Synthesis of Birnessite Type Using Sol-Gel Method for Methylene Blue Degradation

Abstract

The need for catalysts for effective and environmentally friendly waste degradation is increasing. Manganese oxide has a layered structure which is theoretically capable of producing catalysis properties. The synthesis was done through variation of mole ratio of precursors and time of washing. The variations ratio of moles of precursors and washing determined the type of manganese oxide. Synthesis of birnessite type manganese oxide has been successfully performed using KMnO 4 and citric acid precursors via sol-gel method. The optimum condition of birnessite synthesis through sol-gel method was obtained in a precursor mole ratio of KMnO 4 and citric acid 3:1, single washing, with a time of calcination for 5 hours, and calcination temperature of 500 °C. The results showed that the ratio of K/Mn atoms were 3.1 to 8.0. Interpretation of infrared absorption shows a typical vibration of birnessite. Birnessite produced has a formula which was KMn 3 O 11. Birnessite can eliminate Methylene Blue up to 97.63%.