Heterogeneous oxidation of naproxen in the presence of α-MnO2 nanostructures with different morphologies

α-MnO2 nanostructures with different morphologies including nanoparticles, flower-like nanostructures and nanorods have been successfully prepared and used in the heterogeneous oxidation of naproxen in water. It has been found out that the heterogeneous oxidation process is highly pH dependent, with higher efficiency at lower pH values. The oxidation kinetics of naproxen were modeled by Langmuir–Hinshelwood equations. Based on the kinetic constants (k), the oxidation efficiency follows the order of commercial particles