Preparation And Properties Of Sulfide-Based Nanometer Diluted Magnetic Semiconductors

It is imperative to develop more desirable photocatalytic materials,which is because that the development of human society faces many severe challenge of the environmental pollution.DMS has broad prospects in optics,magnetism and photocatalysis fields,with magnetic materials and semiconductor materials.In this paper,sulfide?ZnS,SnS₂?based nano-diluted magnetic semiconductor materials were prepared by hydrothermal method.The microstructure,optical,magnetic and photocatalytic properties of the material were systematically studied by XRD,SEM,HRTEM,SAED,EDS,XPS,UV-vis,FTIR,PL and VSM.The main results are as follows:One.ZnS-based Nano Diluted Magnetic Semiconductor SystemThe Zn_0.95M_0.05S and Co-Ni co-doped ZnS nanorods are successfully prepared by hydrothermal method.ZnS nanocomposites are investigated by varieties of test techniques to study the microstructure,optical properties and magnetic properties,which is effected by the type and content of doping elements.1.Pure ZnS and doped Zn_0.95M_0.05S?M=Cr,Ni,Co,Fe and Mn?nanorods with different ionic radius are still wurtzite structure.The unit cell volume,bond length and the lattice constant also decrease with the increase of doping ionic radiu.The morphology of the samples is a one-dimensional nanorods.The PL spectrum exhibits distinct ultraviolet and blue light emission peaks,and the emission intensity is significantly enhanced.Along with the doping ionic radiu increasing,the optical band gap occurs redshifts.Meanwhile,all samples are room temperature ferromagnetism,as the saturation magnetization decreasing.2.Pure ZnS and Zn_0.95-xCo_0.05Ni_xS nanorods are successfully synthesized with ethylenediamine.All samples possess wurtzite structure with well-crystallized.The morphology is all one-dimensional and well-dispersed.The optical bandgaps of doped samples are larger than pure ZnS.With Ni doping concentration increasing,the blue emission peaks are quenched.All samples exhibit ferromagnetism at room temperature with increased saturation magnetization.Two.Sn S₂-based Nano Diluted Magnetic Semiconductor SystemThe magnetic properties and photocatalytic properties of Cr-doped SnS₂ diluted magnetic semiconductors and the photocatalytic properties of Ag₂S@SnS₂ composites are researched by kinds of characterization,respectively.1.Different morphology of SnS₂ are prepared using different reaction molar ratio,time,temperature and complexing agent,like nanoblocks,nanoflowers and nanosheets.The dye adsorption and photocatalytic of synthesis samples are studied on the influence of microstructure.SnS₂ nanoflowers show excellent performance.2.Sn_1-xCr_xS₂ nanoflowers with different doping proportions are synthesized by hydrothermal method using triton as modifier.The PL intensity of Sn_1-xCr_xS₂ nanoflowers is quenched with different doping proportions.Optical band gap occurs blue shift.All samples posess wurtzite structure,which shows room temperature ferromagnetism.Sn_1-xCr_xS₂ exhibits good photocatalytic activity with excellent stability and cyclical.3.The photocatalytic degradation of Rh B by Ag₂S@SnS₂ composites and the mechanism of degradation are studied by hydrothermal method.Ag₂S forms a heterojunction on the surface of SnS₂ nanoflowers via situ ion exchange.The photocatalytic of composites is improved with better stability at 3%Ag₂S@SnS₂.Both photogenerated holes and hydroxyl radicals as main actives pecies affect the photocatalytic efficiency.