Synthesis And Properties Of Photocatalytic Materials Based On Hydroxyapatite

Hydroxyapatite?HAP?is a photocatalytic material with simple synthesis process,which has been applied in the treatment of wasted water containing organic compounds.HAP with various properties can be prepared by reasonably controlling the synthesis conditions during the synthesis of HAP,which can achieve the adjusted of property of HAP.In this paper,the performance of the photocatalysis of HAP was turned by controlling the adding speed of materials in the process of the HAP synthesis,roasting system,loading metal catalyst and so on,and it was applied to the degradation of methyl orange dye.The results obtained in this paper are follows:?1?The influence of the adding methods on the crystallinity and particle size of HAP was obvious.Nano spherical HAP with high photocatalytic property and the particle size of about 44 nm and 65.1%crystallinity was synthesis when the adding rate was 0.23 m L/s.Methyl orange could be completely mineralized under ultraviolet illumination by HAP which could be judged that the structure was stable and there was no dissolution according to infrared spectra.?2?The size,composition and crystallinity of HAP were the main characteristics that were affected by roasting system.Weighty factor analysis that was conducted according to the results of photocatalytic degradation of methyl orange dye indicated that the influence of the crystallinity of HAP on the photocatalytic properties was the biggest and the size and the components of HAP was follow.When particle size is less than 300 nm,the lower crystallinity,the higher purity and the larger particle size of HAP is,the better photocatalytic activity of HAP is.?3?TiO₂/HAP was prepared by the method of the hydrolysis,and its photocatalystic degradation mechanism was explored.The photocatalytic activity of TiO₂/HAP is better than the photocatalytic activity of HAP.It was found that there is synergy between TiO2 and HAP that the life of photoelectron can be prolonged by HAP and the photocatalytic efficiency of TiO₂/HAP would be improved.