Researchers from Iran University of Science and Technology have produced nanoparticles have developed nanoparticles which show photocatalytic properties at the range of visible light and can be recycled and reused due to their magnetic properties.
Titanium dioxide (TiO2) is known as the best photocatalyst among all other photocatalysts due to its unique properties, including perfect catalytic activity, non-toxicity and low price. However, the separation of photocatalytic powders and using them again after water purification treatment cause serious problems. The use of magnetic powders coating with titanium oxide under the title magnetic photocatalysts has been recently proposed to overcome this problem. The photocatalysts can be separated from water by using an external magnetic field.
In this research, bismuth ferrite was used instead of titanium oxide, which has two advantages over titanium oxide. First of all, bismuth ferrite has magnetic properties at nanometric scale, so it does not require a magnetic core. The second advantage is that bismuth ferrite shows a very good photocatalytic behavior at the range of visible light, contrary to titanium oxide whose majority of photocatalytic properties are at the range of ultraviolet light.
This research presents a cheap method by using relatively cost-effective raw materials at low temperature for the synthesis of bismuth ferrite nanoparticles. According to the results, these nanoparticles show an appropriate performance in the purification of wastewater.
Taking into consideration the advantages of bismuth ferrite over titanium oxide and the fact that it is non-toxic and harmless to the environment, it is expected that it can play an important role in decreasing the water and air pollution as well as costs after its mass-production.
Results of the research have been published in Ceramics International, vol. 41, issue 8, 2015, pp. 9642-9646.