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采用“溶胶-凝胶与微波二步法”合成了碳、氮掺杂的锐钛矿(C,N)-TiO_2光催化材料.首先采用溶胶-凝胶方法制备了TiO_2前驱物凝胶粉末,然后将其与盐酸胍混合微波制备(C,N)-TiO_2纳米材料.对该材料进行X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis DRS)等表征,并测试在甲基橙溶液(100mg/L)中的黑暗吸附以及饱和黑暗吸附后的甲基橙光催化降解等性能.结果表明,获得的材料为纯锐钛矿相的二氧化钛.颗粒分散好,平均粒径约20 nm.具有大的比表面积.随着C、N含量的增加,可见光区域的吸收增加,而紫外光区域的吸收基本不随C、N的含量变化;所制备的(C,N)-TiO_2对甲基橙溶液具有超快的黑暗吸附能力(t<1min);在微波处理中,随着盐酸胍的添加量增加,光催化的量子效率先增加后减小.最好的样品能在20 min内对甲基橙的降解效率达到93%.在可见光区域的吸收与黑暗吸附2个因素中,黑暗吸附的作用更大.文章认为微波处理光催化材料的方法简单、快速、节能,是提高光催化速率的有效途径,值得推广.
Carbon and nitrogen-doped anatase (C, N) -TiO_2 photocatalytic materials were synthesized by sol-gel and microwave two-step method.Firstly, TiO_2 precursor gel was prepared by sol-gel method (C, N) -TiO 2 nanomaterials were prepared by microwave mixing with guanidine hydrochloride.The XRD, SEM, UV-Vis DRS ) And other properties, and tested in the methyl orange solution (100mg / L) of dark adsorption and saturated dark adsorption of methyl orange photocatalytic degradation performance results show that the material is pure anatase phase of titanium dioxide. The particles are well dispersed and the average particle size is about 20 nm, with a large specific surface area.With the increase of C and N content, the absorption in the visible region increases, while the absorption in the UV region does not change with the content of C and N. (C, N) -TiO_2 has an ultrafast dark adsorption capacity (t <1min) on methyl orange solution. With the addition of guanidine hydrochloride, the quantum efficiency of photocatalytic first increases and then decreases after microwave irradiation. The best sample can degrade methyl orange to 93% within 20 min. Absorption in the visible region with dark absorption Among the two factors attached, the effect of dark adsorption is greater.It is believed that the method of microwave treatment of photocatalytic materials is simple, rapid and energy-saving, which is an effective way to improve the photocatalytic rate and is worth popularizing.