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以溶胶-凝胶法制备了不同煅烧温度及不同Gd掺杂量的TiO_2(TiO_2:x%Gd)粉末。对改性前后TiO_2结构和性能进行了表征,研究了Gd掺杂TiO_2粉末在紫外光下对苯甲羟肟酸的光催化性能。结果表明:相比纯TiO_2,适量Gd掺杂使TiO_2的光吸收强度增大、粒径减小且比表面积增大。掺杂后的TiO_2粉末具有很高的光催化活性,500℃煅烧的TiO_2:0.70%Gd催化剂光催化活性最佳,室温下300 W汞灯照射120 min后,对苯甲羟肟酸的降解率高达94.7%。总有机碳(TOC)测试显示,加入TiO_2:0.70%Gd后,苯甲羟肟酸矿化率达79.3%,苯甲羟肟酸降解后可能转化为有机小分子物质及无机CO_2和NO_3~-等。此外,Gd掺杂TiO_2重复使用4次后,苯甲羟肟酸的光催化降解率无明显降低,表明稀土Gd掺杂TiO_2是一种有效稳定的光催化剂。
TiO 2 (TiO 2: x% Gd) powders with different calcination temperature and different Gd doping amount were prepared by sol-gel method. The structure and properties of TiO_2 before and after modification were characterized. The photocatalytic activity of Gd-doped TiO_2 powders on benzoyl hydroxamic acid under ultraviolet light was studied. The results show that compared with pure TiO 2, the appropriate amount of Gd doping increases the light absorption intensity of TiO 2, the particle size decreases and the specific surface area increases. The photocatalytic activity of TiO 2: 0.70% Gd catalyst calcined at 500 ℃ is the best. The degradation rate of benzoylhydroxamic acid after 300 W mercury lamp irradiation at room temperature for 120 min Up to 94.7%. Total organic carbon (TOC) test showed that the addition of TiO 2: 0.70% Gd resulted in 79.3% of hydroxamic acid mineralization and the degradation of benzohydroxamic acid could be converted into small organic molecules and inorganic CO 2 and NO 3 - Wait. In addition, the photocatalytic degradation rate of benzohydroxamic acid did not decrease significantly after Gd doped TiO 2 was reused for 4 times, indicating that rare earth Gd doped TiO 2 is an effective and stable photocatalyst.