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为研究由还原氧化石墨烯(RGO)和具有高活性晶面的TiO_2组成的复合材料的制备方法及其光催化性能,首先采用两步水热法制备了RGO/纳米TiO_2复合材料:第1步为合成暴露高活性晶面的纳米TiO_2;第2步为将合成的纳米TiO_2与氧化石墨烯(GO)复合,形成RGO/纳米TiO_2复合材料。然后,利用XRD、SEM、X射线光电子能谱仪和紫外-可见漫反射光谱等手段对制备的暴露不同晶面的纳米TiO_2和RGO/纳米TiO_2复合材料进行了表征,评价了其光催化性能。结果表明:在水热法的第1步中,通过调节HF的浓度能可控制备出具有高活性的(001)和(101)晶面的纳米TiO_2,氟原子在纳米TiO_2中以物理吸附态和化学结合态这2种形态存在;在第2步后,GO与纳米TiO_2复合形成RGO/纳米TiO_2复合材料,同时在此过程中GO被转化成RGO。在紫外光照射下,两步水热法合成的RGO/纳米TiO_2复合材料具有很好的光催化性能,明显优于商用TiO_2(P25)和纳米TiO_2的。RGO/纳米TiO_2复合材料的光催化性能有明显的提高,RGO和TiO_2暴露的晶面对光催化活性有影响。
In order to study the preparation and photocatalytic properties of RGO and TiO 2 with high active surface, a two-step hydrothermal method was used to prepare RGO / nano-TiO 2 composites: Step 1 For the synthesis of highly active crystal surface exposed nano-TiO 2; the second step is the synthesis of nano-TiO 2 and graphene oxide (GO) composite to form RGO / nano-TiO 2 composite material. Then, the prepared nano-TiO 2 and RGO / nano-TiO 2 composite with different crystal planes were characterized by XRD, SEM, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance spectroscopy, and their photocatalytic properties were evaluated. The results show that in the first step of hydrothermal method, the nano-TiO 2 with highly active (001) and (101) crystal planes can be controlled by adjusting the concentration of HF. In the nano-TiO 2, And the chemically bound state. After the second step, GO and nano-TiO 2 are combined to form the RGO / nano-TiO 2 composite, and at the same time GO is converted into RGO. Under UV irradiation, the RGO / nano-TiO 2 composite synthesized by the two-step hydrothermal method has good photocatalytic activity and is obviously superior to commercial TiO 2 (P 25) and nano TiO 2. The photocatalytic activity of RGO / nano-TiO 2 composite was obviously improved. The crystal planes exposed by RGO and TiO 2 had an influence on the photocatalytic activity.