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分别以乙二胺、三乙胺和尿素为氮源,采用溶胶-凝胶法成功制备不同氮掺杂的TiO_2光催化剂,通过X射线衍射(XRD)、扫描电镜(SEM)、激光粒度仪、紫外-可见漫反射(UV-Vis DRS)对样品进行表征,以亚甲基蓝为目标降解物,在紫外与可见光下分别比较不同氮源掺杂对光催化剂活性的影响,实验表明,在紫外光照下,以尿素为氮源制备的N-TiO_2具有较高的催化活性,反应2 h,降解率可达96.2%;而在可见光下,以三乙胺为氮源制备的N-TiO_2具有较高的催化活性,反应6 h,降解率可达92.5%;光催化降解亚甲基蓝的过程近似符合拟一级反应动力学;以三乙胺为氮源制备的TiO_2光催化剂在重复使用4次后仍保持较高的催化活性。
Different nitrogen-doped TiO 2 photocatalysts were successfully prepared by sol-gel method using ethylenediamine, triethylamine and urea as nitrogen sources respectively. The structures of the catalysts were characterized by X-ray diffraction, scanning electron microscopy, laser particle size analyzer, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) was used to characterize the samples. Methylene blue was used as the degradation target. The effects of different nitrogen sources on the photocatalytic activity were compared under ultraviolet and visible light. N-TiO_2 prepared by using urea as the nitrogen source has high catalytic activity, and the degradation rate can reach 96.2% after reacting for 2 h. In visible light, N-TiO_2 prepared by using triethylamine as nitrogen source has high catalytic activity Activity and reaction for 6 h, the degradation rate could reach 92.5%. The photocatalytic degradation process of methylene blue approximated the quasi-first-order reaction kinetics. The TiO 2 photocatalyst prepared with triethylamine as nitrogen source remained high after repeated use for 4 times Catalytic activity.