CeO2/g-C3N4复合光催化剂的制备及其性能研究

采用高温聚合有机物前驱体的方法,以三聚氰胺为前驱体,制得类石墨型氮化碳(g-C₃N₄)粉末,采用水热法制得CeO₂/g-C₃N₄复合光催化剂,对其进行了表征,考察了CeO₂/g-C₃N₄复合光催化剂在可见光下处理亚甲基蓝的性能,并对CeO₂/g-C₃N₄复合光催化剂进行回收实验、吸附实验以及光催化动力学分析。结果表明,CeO₂/g-C₃N₄中g-C₃N₄和CeO₂分别为石墨相和萤石相,复合CeO2使得g-C₃N₄的吸附性能有了大的提高,15 min能达到吸附平衡,吸附82.5%的亚甲基蓝;45 min后对亚甲基蓝处理率达到99.45%,远远快于g-C₃N₄。CeO₂/g-C₃N₄在5次使用后仍然可以保持73.1%的净化效果。亚甲基蓝处理过程包括吸附和光解2部分,光解反应符合一级动力学方程。

Study on the Preparation and Performance of CeO2/g-C3N4 Composite Photocatalyst

The method of polymerizing organic precursors at high temperature was used with melamine as the precursor to prepare graphite-like carbon nitride(g-C₃N₄) powder.The CeO₂/g-C₃N₄ composite photocatalyst was prepared by hydrothermal method.All synthetics were characterized.The treatment performance of the CeO₂/g-C₃N₄ composite photocatalyst on the degradation of methylene blue under visible light was investigated,and the recovery experiment,adsorption experiment and kinetic analysis of CeO₂/g-C₃N₄ composite photocatalyst were carried out.The results showed that,in CeO₂/g-C₃N₄,g-C₃N₄ and CeO₂ were graphite phase and fluorite phase,respectively.The composite CeO2 greatly improves the adsorption performance of g-C₃N₄.The adsorption equilibrium could be reached in 15 min,and 82.5% of methylene blue could be adsorbed.The treatment rate of methylene blue reached 99.45% by CeO₂/g-C₃N₄ after 45 min,which was much faster than the rate by g-C₃N₄.CeO₂/g-C₃N₄ could still maintain 73.1% purification effect after five times of reuse.The treatment process of methylene blue by CeO₂/g-C₃N₄ included adsorption and photolysis,and the photolysis reaction conformed to the first-order kinetic equation.