Preparation And Performance Research Of Photocatalytic TiO₂ In Visible Light

In this article, the TiO₂ gel and modified TiO₂ gel is prepared at low temperature with thepreliminary body which is prepared with titanium and ammonia. Dicusses the photocatalyticdegradation of TiO₂ and modified TiO₂ to C₁₆H₁₈ClN₃S·3H₂O and C₁₄H₁₄N₃NaO₃S, and theeffect of preparing temperature, heating time, PH, the state of TiO₂ and environmentaltemperature on photocatalytic properties. With XRD, TEM amnd SEM, analyzes the size,conglomeration and crystal structure of TiO₂.Survey results show that:TEM and XRD diffraction analysis show that when PH is 6.5～6.9, heating temperatureis more than 70℃and heating time is 2h, the granule of TiO₂ is regular ball and the diameteris about 10nm.In ultraviolet radiation, the degraditive rate of C₁₆H₁₈ClN₃S·3H₂O and C₁₄H₁₄N₃NaO₃Sincreases with the content of TiO₂ increasing, then minish.In ultraviolet radiation, the degraditive rate of C₁₆H₁₈ClN₃S·3H₂O and C₁₄H₁₄N₃NaO₃Sincreases with the preparing and environmental temperature calefying: the degraditive rate ofTiO₂ to C₁₆H₁₈ClN₃S·3H₂O is 75.3%～81%. At environment temperature 20～40℃,the TiO₂prepared at 70℃can degradate C₁₆H₁₈sClN₃S·3H₂O 75.3%～83.1%. But only when theenvironment is more than 30℃, the TiO₂ can degrades C₁₄H₁₄N₃NaO₃S.From this experiment, a best adulteration concentration can be found. When joining 0.4%Cu²⁺ and 1% Fe³⁺, modified TiO₂ has the best photocatalytic properties.In visible light, the degraditive rate of Cu²⁺/TiO₂ to C₁₆H₁₈ClN₃S·3H₂O adds with hepreparing and environmental temperature calefying, the degraditive rate can reach 80% atmost; but the TiO₂ jioned 0.4% Cu can not degrade C₁₄H₁₄N₃NaO₃S.In visible light, the degraditive rate of Fe³⁺/TiO₂ to C₁₆H₁₈ClN₃S·3H₂O adds with thepreparing and environmental temperature calefying. Furthermore, the TiO₂ jioned 1% Fe canalso degradate C₁₄H₁₄N₃NaO₃S, when the preparing temperature is more than 80℃, andenvironmental more than 30℃, it can degrade C₁₄H₁₄N₃NaO₃S, the degraditive rate of C₁₄H₁₄N₃NaO₃S reach 79.2ï¼…at most.In visible light, when the TiO₂ which metal is joined in photocatalyze degradable matter,the degraditive rate minishs, but the degraditive content increases. With the concentration ofC₁₆H₁₈ClN₃S·3H₂O increasing from 3.37g/Lto8.2g/L, the Cu²⁺/TiO₂ prepared at 70℃degradate it from 73ï¼…to 62ï¼…, the degraditive content is from 2.47g/L to 5.09g/L.,the Fe³⁺/TiO₂ prepared at 70℃degradate it from 78.9ï¼…to 67ï¼…, the degraditive content from 2.66g/L to5.5g/L.When the concentration of C₁₄H₁₄N₃NaO₃S increases from 5.3g/Lto12.5g/L, the Fe³⁺/TiO₂ prepared at 90℃can degradate C₁₄H₁₄N₃NaO₃S from 73.4ï¼…to 66.2ï¼…, the degraditivecontent from 3.89g/L to 8.27g/L.In visible light, because of the HNO₃ existing, the degraditive rate of modified TiO₂ isbetter than the modified TiO₂ in water.