| Hollow shells represent a new type of functional materials with high specific surface area, surfacepermeation, low density, can be potentially applied in drug transprotion, chromotographic filler, catalysis,solar cells etc. Among the various synthetic method for hollow spheres, template method is the mostdirectly and efficient approach. In this thesis, the most simple hard template method was adopted toproduce hollow nanospheres, and the photocatalysis and adsoption properties were investigated.Carbon quantum dots are novel carbon materials developed rapidly in recent years, owing to the meritsof high fluorescence intensity and excellent photo-and chemical resistance, size dependent emissionwavelength, as well as the in vivo compatibility, carbon quantum dots are of great significance in cellularand imaging, drug transportion and acid, basic, molecules sensing. In this work, carbon quantum dots weresynthesized via calcination, and the influencing factors on the quantum yield were detailedly investigated.The main contents of this thesis include:1, TiO2hollow spheres were synthesized using MF spheres as template, the photocatalytic activity ofthe obtained materials were tuned by varying the PVP amount, and the hollow spheres demonstrated thehighest photocatalytic activity with the PVP dosage of0.01g. The photocatalysis mechanism showed thatthe photodegradation proceeded via active radicals. The template method used in this work can be used as ageneral approach for preparation of hollow shells.2, Porous SnO2hollow shells were successfully synthesized with carbon spheres as template. Thesurface properties of the porous hollow shells can be tuned by different SnCl2·2H2O dosage，the materialsynthesized with the SnCl2·2H2Odosage of0.2256g exhibited the highest specific surface area and thesmallest size, and therefore the highest adsorptivity for azofuchsine.The method adopted can be developedas a general way for synthesis of hollow spheres。3, A simple calcination was used to effectively synthesis of hydrophilic carbon quantum dots withnegative surface charge, narrow emission peaks, excitation dependent emission and high quantum yieled(90%). The spectra features of the carbon dot were systematically characterized. The results showed thatthe quantum yieled of carbon dot is related to the calcination time and temperature, and the fluorescence ismainly caused by surface traps. |
