Study on Amorphous Hydrous Zirconia by Infrared Spectrum

The structures of precursor of zirconia(a kind of amorphous hydrous zirconia prepared by sol-gel)were studied by infrared spectrum(IR),X-ray diffraction(XRD),differential thermal analysis(DTA)and weight loss(TG)in detail.The results indicated that there are three different near structures in amorphous hydrous zirconia.The different near structures can be found by infrared adsorption spectrum.In the band of 1700～1200cm-1,there are four absorption peaks for hydroxyl bending vibration.They are 1633,1551,1400 and 1340cm-1 respectively.We suggest that the 1633cm-1 belonged to physical adsorbed H2O,the 1564cm-1 belonged to coordinated H2O,the 1400cm-1 belonged to bridging hydroxyl group,and the 1340cm-1 belonged to coordinated hydroxyl group.It indicates that there are four different hydroxyl groups in these amorphous hydrous zirconia,and three different near structures.We suggested three modals for them.The cause of formation of these different structures is the difference of pH values in their preparation sol-gel reaction.The reason of formation different crystalline phases of zirconia from amorphous hydrous zirconia prepared in different pH value is the different near structures of them.