Preparation Of Poly (Trazine Imide) And Its Performance In Uranyladsorption And Photocatalytic Tetracycline Degradation

In recent years,water pollution has become increasingly serious.Uranyl ion in industrial wastewater is radioactive and chemically toxic,which could cause damage to human health.The excessive content of antibiotics such as tetracycline in medical wastewater is harmful to human health and to the natural environment.Therefore,developing efficient techniques for remedation of uranium ions and degradation of tetracycline from wastewater has attracted extensive attention.As a kind of C_xN_ylayered polymer-inorganic semiconductor with high abundance and high specific surface area,poly（triazine imide）（PTI）has higher crystallinity than g-C₃N₄,and it is expected to give promising performance for adsorption of heavy metal ions like UO₂²⁺and for photocatalytic degradation of tetracycline.The main research contents of this paper are as follows:1.PTI was synthesized by molten salt method.The successful synthesis of PTI has been proved by XRD and IR analysis.In addition,its specific surface area and morphology are characterized by BET and SEM.2.The performance of the synthesized PTI and g-C₃N₄in the adsorption of U（Ⅵ）was comparatively evaluated.The results show that the U（Ⅵ）adsorption capacity of PTI is 135.5 mg/g,which is 48 times that of g-C₃N₄（2.8 mg/g）.The results of U（Ⅵ）adsorption kinetics and thermodynamics over PTI state that the adsorption of U（Ⅵ）is an endothermic process.XPS analysis clearly demonstrate that the valence state of U dose not change before and after the adsorption,i.e.positive hexavalent.3.The photocatalytic degradation performance of PTI and g-C₃N₄was compared.The experimental results under the conditions of 10 mg catalyst degrading 50 mL of tetracycline hydrochloride（TC）solution with an initial concentration of 50 mg/L,show that the rate constant of TC photocatalytic degradation over PTI is 0.008 min^-1,which is about five times that of g-C₃N₄(0.0015 min^-1).At the same time,the effects of TC concentration,PTI dosage and the solution pH on the photocatalytic degradation of TC by PTI are explored.