采用水热法在不使用模板剂的条件下合成了在水中分散良好、粒径为300～800nm、规则的锐钛矿型TiO_2微球.用NH_4VO_3和FeC_2O_4按原子分数为0%、0.8%、1.6%、2.4%进行V~(5+)、Fe~(3+)掺杂;当TiO_2质量浓度为0.134g/L、pH值为9时进行可见光降解20mg/L亚甲基蓝实验.结果表明,V掺杂的降解效果与P25粉接近,Fe掺杂有抑制光催化的效果,钒铁共掺杂则呈现出短期降解能力优于未掺杂微球,并且比P25粉沉淀得更彻底、更迅速.通过XRD、FTIR、SEM分析发现,TiO_2微球是由粒径约为10nm的晶粒组成,V~(5+)进入TiO_2的晶格,Fe~(3+)则以Qfe_2O_3形式存在于微球中.
Using hydrothermal method without templates, brookite TiO_2 spherical micro particles are successfully synthesized whose diameter sizes are 300～800nm, The TiO_2 spherical micro particles co-dopes with V~(5+) and Fe~(3+) introduced by NH_4VO_3 and FeC_2O_4 with the atom fraction of 0%, 0. 8%, 1. 6% and 2. 4%. Add the samples with a quantum of 0. 134g/L into the solutions to degrade 20mg/L methylene blue solution under the visible light at pH=9. The results show that the degradation ability of V~(5+) doped spherical micro particles is close to P25( the photo-catalysis of Fe~(3+) doped TiO_2 spherical micro particles appears inhibition for the Q-Fe_2O_3;the degradation ability of V~(5+) and Fe~(3+) co-doped samples is better than the undoped samples in the beginning, and the spherical micro particles sink more quickly compared with P25 powder. The analytical results of XRD, FTIR and SEM reveal that V~(5+) and Fe~(3+) get into the TiO_2 crystal lattice, enhance the visible light response at first and decrease the response 50min later. The doped TiO_2 spherical particles assembled by nano particles whose diameter is about 10nm, present a micro multi-porous structure. The V~(5+) dopant gets into the TiO_2 spherical micro particles' crystal and Fe~(3+) exists in the form of Q-Fe_2O_3.
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