Study On Luminescence And Photocatalytic Properties Of CaTiO₃:Er³⁺

Issues such as increasing global energy consumption and deteriorating environmental climate have become the primary issues facing people.As a new generation of green luminescent materials,rare earth luminescent materials have been widely used in daily life,such as transportation,safety signs,information,electronic display,LED semiconductor lighting and so on.In particular,various types of luminescent materials have been widely used in subways,highway tunnels,cities,business centers,etc.,and the environmental conditions of these public places have also become the focus of attention in recent years,and materials with luminescent and photocatalytic environmental purification composite functions.It will inevitably become a huge new demand for society.In this paper,aiming at the luminescent and photocatalytic environment purification composite functional materials as the research goal,according to the excellent crystal structure conditions of perovskite CaTiO₃ as the luminescent lattice matrix,the rare earth Er³⁺doped perovskite is selected,and explore its luminescent and photocatalytic composite functions.Based on theoretical research,test analysis methods such as X-ray diffractometry?XRD?,scanning electron microscopy?SEM?,fluorescence spectrometer,and UV-visible diffuse reflectance analyzer?UV-vis DRS?,the process conditions,luminescence properties and photocatalytic activity of CaTiO₃:Er³⁺powders synthesized by citric acid complex combustion method were optimized.The orthorhombic CaTiO₃:Er³⁺green phosphor with high luminescence intensity was synthesized under the optimized conditions of combustion ignition temperature900?C,holding time 60 min and Er³⁺molar concentration 2%.The fluorescence spectrum indicates that the strongest excitation peak is the ⁴I_15/2?²G_9/2 transition of Er³⁺at 382 nm,and the emission peak is ⁴F_9/2?⁴I_15/2 transition of Er³⁺at 553 nm.As the Er³⁺doping concentration of the luminescent center is from 1%to 2.5%,the luminescence intensity increases,the Er³⁺concentration continues to increase,and the luminescence intensity begins to decrease until concentration quenching occurs.The incorporation of an appropriate amount of charge compensator Na⁺is beneficial to increase the crystallinity,fluorescence intensity and color purity of the synthesized sample.The photocatalytic degradation results of the synthesized CaTiO₃:2%Er³⁺and CaTiO₃:2%Er³⁺,1.5%Zr⁴⁺show that the latter is under ultraviolet light for methylene blue?MB?,methyl orange?MO?and rhodamine B?RhB?has better degradation ability than the former;Under the condition of xenon lamp simulating visible light,CaTiO₃:2%Er³⁺had the best degradation effect on MB.After 180 min illumination,the degradation rate of MB was 77%,while MO and RhB were 60%and18%,respectively.The CaTiO₃:Er³⁺powder material synthesized in this paper has the composite function of green luminescence and photocatalytic environment purification,and has potential application value in related fields.