Takuya Suzuki
The University of kitakyushu
Name: Takuya Suzuki, Associate ProfessorSpecial: Inorganic chemistry, Instrumental Analysis, Photo-active materials
Recently, photo-catalyst has been widely used as disinfect, antifouling system, solar cell, and etc., cause they are clean and eco-materials without fossil fuel using. Especially, Perovskite photo-catalysts were focused as... [ view full abstract ]
Recently, photo-catalyst has been widely used as disinfect, antifouling system, solar cell, and etc., cause they are clean and eco-materials without fossil fuel using. Especially, Perovskite photo-catalysts were focused as high performance solar cell, their chemical stability and replace-ability of A and B sites within the structures.
In this study, we forced Ti-based Perovskite materials such as ATiO3 (A=metals). Six types Perovskite photo-catalysts synthesized, and A site substituted to K, Rb, Sr, Pb, La, and Pr. Also effects to physical properties of these materials were studied.
Ti-TEOA was prepared by mixing Titanium tetraisopropoxide (TIPO) and 2,2’,2’’-nitrilotriethanolamine (TEOA) in dry air at 1 day. Concentration of Ti–TEOA was adjusted by adding to ion-exchange water. The molar ratio of TEOA/TIPO and concentration of Ti4+ were adjusted to 2/1 and 0.50 mol/L, respectively. Next, each potassium hydroxide, rubidium hydroxide, strontium hydroxide, lead nitrate, lanthanum nitrate, and praseodymium nitrate was added to this mixed solution. The each solution mixing time are 90 min and were heated by hydrothermal method at 140oC for 72h. The gel were washed three time using ion-exchange water and freeze dried. Each Perovskite photo-catalyst were achieved by calcination at 1000 oC for 15h. Products were characterized K2Ti6O13, Rb2Ti6O13, SrTiO3, PbTiO3, La2Ti2O7 and Pr2Ti2O7 by XRD. And physical property of each Perovskite photo-catalyst were measured by FE-SEM, surface area measuring and UV-Vis. SrTiO3 show the largest surface area in all Perovskite photo-catalyst. PbTiO3 had the largest visible light absorption band. Pr2Ti2O7 was had two visible light absorption bands between 400 and 600nm.
Photo-activities were measured by oxidation decomposition reaction of acetic acid and reduction dye decomposition reaction of methylene blue. PbTiO3, SrTiO3, and La2Ti2O7 show high acetic acid decomposition because they had visible light absorption band and they could use visible area light. SrTiO3 show highest dye decomposition activity, however this owed its biggest surface area. When we calculated dye decomposition activity par unit surface area, K2Ti6O13 and Rb2Ti6O13 show highest dye decomposition ability. The monovalent metals worked as good electron donor by A site displacement from divalent metal.
