| Tin dioxide(SnO2)is a typical wide bandgap(Eg=3.6V)oxide semiconductor material and has a wide range of applications in ceramics,transparent conductive,luminescent materials,flat panel displays,solar cells,gas sensors,catalysts,etc.,due to its excellent optoelectronic properties,gas sensing properties and thermochemical stability.The construction of SnO2 low-dimensional nanostructured materials and ion doping have an important influence on the crystal structure,electronic band structure and electromagnetic transnission characteristics of SnO2,which can further improve the thermochemical stability of the material and improve its photoelectric performance index.Therefore,it is a research hotspot in the field of materials science.The paper uses transition metal ions and rare earth ions as doping elements to synthesize various forms of SnO2-based low-dimensional nanostructured materials by hydrothermal method to expand its applications in the fields of optics,electronics,and optoelectronics by utilizing the advantages of nanomaterials combined with doping modification technology.The main research contents and conclusions are as follows:1?Co and Mn-Co co-doped SnO2 nanoparticles were synthesized by citrate precursor assisted coprecipitation(CPACP).Co and Mn ions were confirmed to successfully incorporate into the SnO2 host lattice without changing its Inherent rutile structure by X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),energy dispersive X-ray fluorescence spectrometry(EDX),X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy.The prepared samples had an average grain size in the range of 8-12 nm.In a single Co2+ doped SnO2 sample,the magnetization increases as the Co2+ ion concentration increases.The transition metal Mn can modulate the magnetic signal of the Co2+ doped SnO2 sample.The addition of proper amount of Mn can increase the magnetization.With the increase of Mn2+ ion concentration,the magnetic properties of(Mn,Co)co-doped SnO2 nanoparticles gradually change from ferromagnetism to superparamagnetism.In particular,when the doped Mn2+ ions were excessive,the sample Sn0.83Mn0.12Co0.05O2 exhibited diamagnetism.2?Different concentrations of Sm3+-doped SnO2 hollow spheres were synthesized based on the carbon template method.The morphology,composition and microstructure of the SnO2 hollow spheres were examined by thermogravimetric analysis(TGA),XRD,scanning electron microscopy(SEM)and Raman spectroscopy.Based on the TGA and XRD data,the optimum calcination temperature was found to be about 750?.The Sm3+-doped SnO2 hollow sphere has a diameter of about 120nm and a shell thickness of about 25nm.It is actually composed of a large number of Sm3+-doped SnO2 nanoparticles,and the average grain size is in the range of 9.6-13.2nm.The Sm3+-doped SnO2 hollow sphere is essentially a sensitized luminescent structure with SnO2 as the host.Photoluminescence(PL)measurements clearly show three strongly visible luminescence peaks in the yellow-red region,with red emission near 610nm being the strongest.The crystallinity,morphology,size and PL emission intensity are sensitively affected by the doping concentration of Sm3+,and the optimum doping is 4.5at.%.The above studies show that trivalent transition metal ion doping and trivalent rare earth ion doping play important roles in controlling the magnetic properties of SnO2-based dilute magnetic semiconductor magnetization and luminescence properties of sensitization illuminants,respectively.This is beneficial for the development of ferromagnetic semiconductors for snO2-based multi-function spintronic devices and for the implementation of SnO2-based luminescent materials in biotags,LEDs,displays,etc.Figure[32]table[7]reference[126]... |
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