Abstract:
The 2x2 tunnel cryptomelane type-manganese oxide has been successfully synthesized
via sol-gel method using KMnO4 (oxidant) and C6H8O7 (reductant). The product was
then treated with acid or base addition to conduct surface modification. This type of
oxide has been reported as an effective catalyst for the degradation of organic wastes
in the heterogeneous Fenton reaction, which is one of the Advanced Oxidation
Processess (AOP). Acid and base treated cryptomelanes, referred to as HAccryptomelane
and KOH-cryptomelane respectively, were characterized using X-ray
Diffraction (XRD). The results indicated that both HAc-cryptomelane and KOHcryptomelane
retained the cryptomelane phase without additional new phases. The assynthesized
HAc-cryptomelane dan KOH-cryptomelane were then applied as catalyst
for the degradation of methylene blue using H2O2 as an oxidant. KOH-cryptomelane
catalyst displayed higher activity for methylene blue (MB) degradation than that of
HAc-cryptomelane with 94.465% MB degradation within 60 minutes of reaction time.