Kinetic Study on the Effect of PH in the Photocatalytic Degradation of Methylene Blue With Fe-FeS Nanocomposite Powder

In this paper, photocatalytic activity of mechanothermally synthesized Fe-39%FeS nanostructured composite powder is investigated. Fe and S powders mixture with atomic ratio of 2:1 (Fe:S) is mechanically activated and then heat treated at 850?C for 2 h. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and UV-vis spectroscopy are applied for characterization of composite powder. XRD results are shown that Fe-FeS powder was synthesized successfully. FESEM images showed that powder with the size of less than 2 ?m is formed after heat treatment. Also, the effect of pH as an effective factor is investigated. It can be seen that the degradation efficiency in basic solution is higher than acidic and neutral solution. Dyes degradation reached to 91% after 195 min irradiation of visible light in pH=11. In addition, kinetic study showed that the photocatalytic dedradation is initially (0-75 min) followed