Isolating the Photocatalytic Degradations of Methylene Blue Dye on TiO2 Surface

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Microscopy and Microanalysis

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Methylene blue, Molecule Surfaces -- Research


Photocatalytic degradation of organic molecules has a broad applicability and has been studied with particular intensity for the purpose of water and air purification [1]. In this process, light is absorbed by a semiconducting material and converted to electron-hole pairs, which in turn react with water molecules to form hydroxyl radicals (•OH). These highly oxidative molecules go on to degrade organic molecules through what is known as an Advanced Oxidation Process (AOP) [2]. However, the result is usually achieved through diverse pathways, and isolation of the individual mechanisms is difficult. In particular, this experiment is designed to isolate the degradation of an organic marker at the surface of the catalyst material, as opposed to degradation away from the catalyst surface (i.e. within the aqueous medium). This has been achieved by designing an experiment to observe the relative mass of methylene blue (MB) on the catalyst surface during a photodegradation reaction. The TiO2 film was deposited onto glass beads in order to immobilize the catalyst material on a visibly transparent substrate, allowing measurement of dye concentration via visible light spectroscopy.


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