Design Of Metal Ion Doped Potassium Titanate One-dimensional Nanomaterial And Theoretical Calculations On Their Photocatalytic Properties

With the rapid development of computer technology,the method of theoretical calculation and simulation is gradually applied to experimental research.The application of theoretical calculation and simulation in photocatalysis not only helps people to study the mechanism of photocatalytic reaction,but also provides theoretical verification and guidance for the modification of traditional wide band gap semiconductor photocatalytic materials and the exploration of new photocatalytic materials.Nowadays,potassium titanate(K₂Ti₆O₁₃)has attracted growing attention because of its high quality performance and low synthesis cost,especially as a photocatalyst.However,K₂Ti₆O₁₃ has a wide band gap of 3.45 eV and shows photocatalytic activity only under UV-light irradiation.In order to extend the response of K₂Ti₆O₁₃ to visible light and improve its photocatalytic activity,in this paper,the electronic structures and optical properties of 3d transition metal?Sc,V,Mn,Fe or Cu?and 4d transition metal?Zr,Nb,Mo,Ru or Ag?doped K₂Ti₆O₁₃ were investigated by means of first-principles calculations.The results showed that K₂Ti₆O₁₃ had little change in the band gap value after doping with 3d transition metals?Sc or V?and 4d transition metals?Zr,Nb or Mo?,so the doping of these transition metals did not achieve the response of K₂Ti₆O₁₃ to visible light.Due to the effect of the impurity levels,the doping of 3d transition metal?Mn,Fe or Cu?and 4d transition metal?Ru or Ag?achieved the response of K₂Ti₆O₁₃ to visible light.What's more,the modification of Cu doping on K₂Ti₆O₁₃ was more effective than that of Mn or Fe doping,and the modification of Ag doping on K₂Ti₆O₁₃ was more effective than that of Ru doping.In order to verify the calculation results,pure?Fe-doped and Ag-doped potassium titanate one-dimensional nanomaterial were prepared by sol-gel and hydrothermal synthesis.Their structures and properties were characterized by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy and ultraviolet-visible spectroscopy.The results showed that the doping of Fe or Ag did not change its crystal structure and nanowire morphologies.Afer doping of Fe or Ag,potassium titanate one-dimensional nanomaterial realized the absorption of visible light.This proved that the calculation model and the calculation results were correct and reasonable in this paper.In addition,pure?Fe-doped and Ag-doped K₂Ti₆O₁₃ all had good degradation ability to rhodamine B.When the doping concentration was low,the doping of Fe or Ag all improved the photocatalytic activity of K₂Ti₆O₁₃.The metal ion doped potassium titanate one-dimensional nanomaterials are expected to become efficient photocatalytic materials with high potentiality for the development.