Presentation Information
[24p-12G-14]Hydrothermal Synthesis of Magnetic Spinel ZnFe2O4 and the Application in Photocatalytic Degradation
〇(M1)Junan An Wang1, Jhen-Yang Wu1, Tomoyuki Kurioka1, Chun-Yi Chen1, Masato Sone1, Yung-Jung Hsu1,2, Satoshi Okamoto1,3, Tso-Fu Mark Chang1 (1.Tokyo Tech., 2.NYCU, 3.Sumitomo Chemical)
Keywords:
photocatalyst,zinc ferrite,dye degradation
Spinel nanomaterials have attracted much attention in the field of photocatalysis. This is not only because of its narrow band gap that is favorable for the visible-light driven photocatalytic reaction, but also because of its magnetic properties and stable physicochemical properties that allows these photocatalysts to be easily recycled and reused. An example of the spinel photocatalysts is ZnFe2O4(ZFO) having the band gap in a range of 1.85 eV to 2.43 eV. In addition, the spinel photocatalysts, including ZFO, could be prepared by a simple hydrothermal synthesis method. This is especially advantageous toward practical application.
For the hydrothermal synthesis of ZnFe2O4, 10 mmol of Fe(NO3)3·9H2O and 5 mmol of Zn(NO3)2 were first dissolved into 20 mL of deionized water containing 15 mmol succinic acid. Then, 6 g of urea and 30 mL of a solution containing 60 g of NaOH were added. The solution was stirred for additional 1 h and transferred to a Teflon-lined stainless-steel high-pressure autoclave. The autoclave was placed in a box oven at 180 ℃ for 48 h. The efficiency in photodegradation of rhodamine B (RhB) under visible-light irradiation was used as an indicator to examine the catalytic performance.
The product was found to be crystalline powders as shown in the SEM image, and these crystalline powders were confirmed to be spineal ZnFe2O4 by the X-ray diffraction patterns. UV-visible spectroscopy was used to determine the concentration of RhB in the solution, and the absorption peaks at 550 nm were caused by the RhB. Intensities of the absorption peak at 550 nm gradually decreased as the irradiation time increased. This demonstrated that the ZnFe2O4 was effective in removal of the RhB by the photodegradation reaction under visible-light irradiation.
For the hydrothermal synthesis of ZnFe2O4, 10 mmol of Fe(NO3)3·9H2O and 5 mmol of Zn(NO3)2 were first dissolved into 20 mL of deionized water containing 15 mmol succinic acid. Then, 6 g of urea and 30 mL of a solution containing 60 g of NaOH were added. The solution was stirred for additional 1 h and transferred to a Teflon-lined stainless-steel high-pressure autoclave. The autoclave was placed in a box oven at 180 ℃ for 48 h. The efficiency in photodegradation of rhodamine B (RhB) under visible-light irradiation was used as an indicator to examine the catalytic performance.
The product was found to be crystalline powders as shown in the SEM image, and these crystalline powders were confirmed to be spineal ZnFe2O4 by the X-ray diffraction patterns. UV-visible spectroscopy was used to determine the concentration of RhB in the solution, and the absorption peaks at 550 nm were caused by the RhB. Intensities of the absorption peak at 550 nm gradually decreased as the irradiation time increased. This demonstrated that the ZnFe2O4 was effective in removal of the RhB by the photodegradation reaction under visible-light irradiation.