Photocatalytic performance of Fe3O4-TiO2 in the degradation of methylene blue dye: Optimizing the usability of natural iron sand

Methylene blue dye is still widely used as a clothing dye in the textile industry. Therefore, it is necessary to process this dye waste before it enters water bodies so that it does not damage the environment. The aim of this research was to optimize the function of magnetite (Fe3O4) extracted from iron sand combined with TiO2 for degrading methylene blue dye. The iron sand was extracted using a bar magnet, sieved, washed, milled, and dried. Iron sand (20 g) was converted into magnetite using the co-precipitation method with a stirring speed of 800 rpm at a temperature of 80 °C for 30 min. Magnetite was mixed with TiO2 with 30 % ethanol using a mechanical stirring method. The characteristics of Fe3O4-TiO2 photocatalyst were tested using XRD, SEM-EDX and VSM. According to the XRD data, the crystal size of the Fe3O4-TiO2 photocatalyst was below 40 nm. The presence of Fe and Ti in the photocatalyst material and their even distribution were determined by SEM-EDX testing. Through VSM, it was confirmed that soft magnetic properties were present in this material. The performance of the Fe3O4-TiO2 photocatalyst in the degradation of methylene blue dye was analyzed using a UV–Vis spectrophotometer. The test results showed that the performance of the photocatalyst improved as the contact time increased and was marked by a decrease in the optical absorption intensity; the best performance of the Fe3O4-TiO2 photocatalyst reached 93 %. Therefore, it can be concluded that iron sand as part of the photocatalyst material, play a role in the photodegradation of methylene blue dye.