Rare Earth Modification Of C₃N₄ And Its Near Infrared Photocatalytic Properties

In today’s human society,with the rapid development of industry,the problem of excessive energy consumption and industrial wastewater pollution has become increasingly prominent,which has seriously affected the natural environment and people’s healthy life,and restricted the process of human development.Finding new energy and removing pollutants from wastewater have become an important task of the current society.In the process of exploring new energy sources,people have found that the sun with the development of human civilization is a huge energy treasure house.Solar energy has attracted much attention because of its clean,pollution-free and huge stock.Efficient use of solar energy to convert it into chemical energy has become one of the important means to solve the problem of future energy shortage.At the same time,solar energy can also be widely used in environmental governance to remove water pollutants,and photocatalytic technology has developed.After years of people’s exploration of solar energy,photocatalytic technology has been widely used to degrade pollutants,decompose water to prepare hydrogen,etc.,which fully proves the great development prospects of this technology.In recent years,non-metallic semiconductor g-C₃N₄has attracted widespread attention in many photocatalytic materials.The main reason is that g-C₃N₄ has effective visible light absorption,good chemical stability and thermal stability,narrow band gap,cheap and easy to obtain precursors,simple synthesis methods and other characteristics,so that this kind of visible light driven photocatalyst has broad application prospects.However,pure graphite phase carbon nitride has some defects,such as easy recombination of electrons and holes,lack of up-conversion ability,and narrow absorption spectral range.These defects make its photocatalytic ability weak,especially near-infrared photocatalytic ability.In order to solve the above problems,the g-C₃N₄ was doped with rare earth and compounded with nano-noble metals to improve its photocatalytic performance,so that it had near-infrared photocatalytic ability,and the reasons for the improvement of near-infrared photocatalytic efficiency were analyzed from multiple perspectives.The energy transfer between rare earth ions and matrix g-C₃N₄ and the mechanism of energy transfer between rare earth ions and matrix g-C₃N₄ were explored:（1）Yb³⁺,Tm³⁺co-doped g-C₃N₄ was synthesized,and its photocatalytic test was carried out.It was found that the near-infrared light absorption and conv ersion ability of g-C₃N₄ was significantly enhanced after doping rare earth ions Yb³⁺and Tm³⁺.In addition,the doped g-C₃N₄ has multiple reactive sites,wh ich promotes the separation of carriers in the material.Finally,g-C₃N₄ exhibits excellent near-infrared photocatalytic performance,which is convenient for appli cation in more fields and places.（2）On the basis of Yb³⁺and Tm³⁺co-doped g-C3N4,the silver nanopartic les were successfully compounded,and the near-infrared photocatalytic test was carried out.It was found that after compounding silver nanoparticles,the plas ma resonance effect was used to enhance the near-infrared light absorption of g-C3N4,thereby enhancing the up-conversion ability of rare earth ions doped g-C3N4,promoting the effective utilization of near-infrared light by g-C3N4,ther eby improving the near-infrared photocatalytic performance of g-C3N4.