更新时间:09-15 (陈老师)提供原创文章
摘要:本实验采用溶胶凝胶法和水热法,分别以KI和I2为碘源, 制备了PVA-I掺杂二氧化钛新型光催化剂。采用XRD、UV-Vis、IR等手段对催化剂进行表征,并以亚甲蓝为目标物,研究了PVA-I掺杂催化剂在可见光下对亚甲蓝溶液的降解效果。实验结果表明:掺杂PVA-I新型催化剂的最佳合成方法为水热法,合成温度对催化剂晶体的发育有影响,合成温度为100℃时催化剂的晶型最好,晶粒最小,光催化性能最好。而碘单质是最好碘源。此外,PVA和碘掺杂可以拓宽催化剂在可见光区域的吸收范围,降低催化剂的禁带宽度。
关键词: TiO2; PVA;碘掺杂;光催化;水热法;溶胶-凝胶法
Abstract: Novel PVA-I doped TiO2 photocatalysts were fabricated by hydrothermal method and Sol-gel method, using KI and I2 as the iodine sources. The catalysts were characterized by XRD, UV-Vis, IR and etc, and the photocatalytic activity was evaluated by photodegradation of methylene blue. The experiment results showed that the best way of synthesized PVA-I doped catalysts are hydrothermal method, and Synthesis temperature affects on the growth of crystalline of catalyst. When the synthesis temperature reach to 100℃, the size of crystal are minimum, the surface area was maximum and photocatalytic performance was best. And the best iodine source is elemental iodine. In addition, PVA and iodine doped can broaden the absorption range of catalysts in the visible region and reduce the forbidden band of catalysts.
Key words: TiO2;PVA;Iodine doped;Photocatalysis;Hydrothermal method; Sol-gel method
(1)采用溶胶凝胶法制备PVA-I掺杂TiO2的催化剂,催化剂样品表征结果显示:在300℃下,可以实现TiO2板钛矿相向锐钛矿相的转变,但是晶粒径相对较大。PVA的掺杂对TiO2催化剂的晶型,粒晶尺寸,禁带宽度及降解性能等没有明显的影响。采用溶胶-凝胶法合成掺杂PVA-I的催化剂不具典型性且不符合本实验要求。
(2)通过对催化剂样品的表征以及对亚甲蓝溶液降解实验的研究,得出了添加PVA-I的新型催化剂最佳合成方法为水热法,并且发现合成温度对催化剂晶体的发育有影响,合成温度为100℃时催化剂的晶型最好,晶粒最小,比表面积最大,光催化性能最好。此外,PVA掺杂可以拓宽催化剂在可见光区域的吸收范围,降低催化剂的禁带宽度。
(3)通过对“催化降解亚甲蓝溶液实验”中各个催化剂降解率的对比以及对各催化剂样品表征结果的对比,实验得出,水热法制备掺杂PVA-I的催化剂最好掺杂碘源为碘单质。