Photocatalytic oxidation is considered to be one of the most effective ways of degrading methylene blue. A number of catalysts have been reported for methylene blue (MB) degradation over the past decade. Photocatalytic degradation oxidizes complex organic compounds into small molecular inorganic substances, such as carbon dioxide and water, under light. ... Photocatalytic oxidation is considered to be one of the most effective ways of degrading methylene.