Microstructure And Spectral Investigation Of Composite ZnO/SnO₂ Nanocrystalline After High Pressure Treatment

Nano zinc oxide(ZnO)is an important semiconductor material,with the similar band gap of the nano-titanium dioxide,is a good photocatalytic material.Nowadays, how to improve the usage factor is attracting many researchers.In particular,High-pressure technology which is a relatively new field,arrest more and more researchers attention.For an attempt,it used into the photocatalytic materials research.When a domain introduces a new technology,its mature theory is essential.In this paper,two kind of photochemical catalysis materials were prepared, and analysis of changes in the structure and the spectral.This provides the theoretical basis for our new photocatalytic materials research in the future:The nano ZnO and nano composite ZnO/SnO₂ materials were prepared by sol-gel method.By a high-resolution transmission electron microscopy and X-ray diffraction(XRD)Characterization,the zinc oxide and composite ZnO/SnO₂ both have good crystallinity,and the size respectively is 17.22nm and 19.68nm.Then they were treated by high pressure method which the pressure is up to 6GPa,the size of them respectively is 16.20nm and 14.50nm,which decrease 5.9%and 26.3%.The nano ZnO and nano composite ZnO/SnO₂ materials were studied by photoluminescence spectrometer,UV-visible absorption spectroscopy and infrared spectroscopy.The photoluminescence spectra intensity of zinc oxide reduced obviously may cause by two reasons:First,the crystallinity enhancement phenomenon is more than lattice distortion phenomenon which both caused by squeeze force;second,reunion phenomenon reduce the exciton emission.For the composite ZnO/SnO₂,accompanied by fragmentation which was more than ZnO caused by stress effect on the SnO₂,the complex grain boundary make the crystallinity less elevated,so as to the photoluminescence spectra intensity reduce less than pure ZnO.After high pressure,the UV-visible and infrared spectra of ZnO and composite ZnO/SnO₂ both have blue-shifted.The former is from 380 blue-shift to 368 and 366nm,the latter is from 438 and 441 blue-shift to 451 and 453 cm^-1.These showed the samples after high-pressure treatment both had good quantum effect.While the infrared characteristic spectra peak of ZnO/SnO₂ were wider than ZnO may caused by two reasons:the different size of the ZnO and the SnO₂,and the complex grain boundary.These results corroborated the above conclusions.