Photodegradation of Methylene Blue Dye by Porous Manganese Dioxide (MnO2)

Abstract

The fast advancement of industry has led to many ecological, environmental, social and biological problems. In order to resolve some of these problems, it is necessary to find suitable highly efficient techniques to resolve them. One of them is the waste water treatment and removing harmful the organic pollutants to make them reusable. Semiconductor nanomaterials are used as photocatalyst due to their potential application for degradation of harmful organic pollutants. Mn-oxides catalysts has been found to be highly effective for the adsorption and photocatalytic degradation of many organic dyes due to their high surface area and multiple oxidation states. In this work, the MnO2 nanopowder has been synthesized through sonochemical route using KMnO4 and poly-ethylene glycol as the reducing agent. Structural and optical analysis (XRD, TEM, FTIR, BET and UV–visible) confirmed the formation of nanocrystalline MnO2 network. The adsorption and photocatalytic performance of synthesized MnO2 was tested for degradation of methylene blue dye and p nitrophenol (2.0 mg/L) under dark chamber and household CFL lamp exposure, respectively. Further, the adsorption and degradation of methylene blue dye has been studied with varying concentration (3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 mg/L) and also at different pH values (2.0, 5.0, 7.0, 10.0 mg/L at 2.0 and 10.0 pH) of the dye solution.