Presentation Information
[25p-31B-10]Degradation of Malachite Green by Photocatalytic NiFe2O4 and the Annealing Temperature
〇(B)Xinyu Jin1, Jhen-Yang Wu1, Tomoyuki Kurioka1, Chun-Yi Chen1, Masato Sone1, Yung-Jung Hsu1,2, Satoshi Okamoto1,3, Tso-Fu Mark Chang1 (1.Tokyo Institute of Technology, 2.National Yang Ming Chiao Tung University, 3.Sumitomo Chemical)
Keywords:
NiFe2O4,photodegradation,magnetism
Persistent organic pollutants (POPs) refer to organic chemicals that persist in the environment because of the long half-life, and this often leads to biomagnification in a food chain. An example of the POPs is malachite green. Malachite green (MG) is used as the dye in clothes and as antimicrobials in aquaculture. MG is toxic to human and is reported to be a potential risk to human cancer. Therefore, removal of MG in the environment, especially the water, is always a research interest.
Photocatalysts are promising in removal POPs in aqueous solutions through photogeneration of highly active radicals capable to decompose the POPs, and the final products are simply CO2 and H2O. NiFe2O4 (NFO) is reported to have a multiple band gap ranged from 1.5 eV to 2.5 eV, and it is a ferromagnetic material. This implies that NFO can generate active radicals by absorbing visible light, and the ferromagnetic property allows easy recover of the NFO particles dispersed in an aqueous solution by a magnet.
The NFO particles were prepared by a hydrothermal method. The as-prepared NFO was amorphous, and the cubic spinel structure was confirmed after sintering at a temperature higher than 400 °C as shown in the X-ray diffraction (XRD) patterns in Fig. 1(a). In the degradation of MG, 40 mg of the NFO was added to 20 mL of a solution containing 25 mg/L of MG. For the 600 °C sintered NFO, 86% of the MG was removed after 2 hrs of the visible light irradiation as illustrated in Fig. 1(b), and the removal efficiency further improved to 90% when ultrasonication was applied as shown in Fig. 1(c)
Photocatalysts are promising in removal POPs in aqueous solutions through photogeneration of highly active radicals capable to decompose the POPs, and the final products are simply CO2 and H2O. NiFe2O4 (NFO) is reported to have a multiple band gap ranged from 1.5 eV to 2.5 eV, and it is a ferromagnetic material. This implies that NFO can generate active radicals by absorbing visible light, and the ferromagnetic property allows easy recover of the NFO particles dispersed in an aqueous solution by a magnet.
The NFO particles were prepared by a hydrothermal method. The as-prepared NFO was amorphous, and the cubic spinel structure was confirmed after sintering at a temperature higher than 400 °C as shown in the X-ray diffraction (XRD) patterns in Fig. 1(a). In the degradation of MG, 40 mg of the NFO was added to 20 mL of a solution containing 25 mg/L of MG. For the 600 °C sintered NFO, 86% of the MG was removed after 2 hrs of the visible light irradiation as illustrated in Fig. 1(b), and the removal efficiency further improved to 90% when ultrasonication was applied as shown in Fig. 1(c)