Experimental Study On Photocatalytic Degradation Of Dye Wastewater By Gd、N、S Co-doped TiO₂with Electeic Field Assisted

Dye wastewater is not only causing serious environmental pollution, but also apotential threat to human.TiO2photocatalyst has great potential in the treatmentof wastewater because of its characteristics of high efficiency, stable,no secondarypollution.However, due to the limit of band width, it is restricted in treatment of dyewastewater.Gd-S and Gd-N co-doped TiO2photocatalyst were made by sol-gel method.The experimental results of Acid Brilliant Scarlet GR’s degradation showed thatthe powder of Gd0.2%-S1.0%co-doped TiO2with calcination temperature of650degrees’ calcination temperature(A catalyst) and Gd0.1%-N2.0%co-doped TiO2with650degrees’ calcination temperature (B catalyst) had the best effect on AcidBrilliant Scarlet GR, which reached68.2%and85.6%respectively.The modified TiO2were characterized by XRD, HRTEM, Raman and BET.Theresults showed that when the calcination temperature was650C, Gd-N co-dopedTiO2appeared to be not directional growth, crystal size was smaller than othertemperature’;And for Gd-N co-doped TiO2, the more N had doped, the degree ofcrystallization was better and the more Advantageous to the growth of rutilephase;The modified of Gd-S and Gd-N could both greatly increased the specificarea of TiO2, and the Gd-N co-doped had bigger one’s.The optical excitation rangeof Gd-S co-doped TiO2shift to the visible light region400nm-550nm.The influence of processing factors showed that Gd-N co-doped had a greaterextent to improve the photocatalytic activity of TiO2relatived to Gd-S co-doped,Gd-S co-doped can expanded TiO2’s optical absorption edge;Catalyst A and B bothhad a relatively good treatment effect to Acid Brilliant Scarlet GR, Safranine T andReactive Yellow X-R;The Reactive Yellow X-R had the best treatment effect whichdecoloration rate can reach89.7%and95.2%, the removal rate of COD can reach81.5%and90.5%.The treatment effect of rhodamine B was poor, whichdecoloration rate was only24.3%and32.2%, and the removal rate of COD was16.7%and25.4%.The best pH was3-7and the best voltage was15V for thetreatment of Acid Brilliant Scarlet GR with modified TiO2which decolorization ratecan reach93.5%.