快速溶胶-凝胶法制备高结晶度氮掺杂介孔TiO2(英文)

Preparation of High Crystalline N-Doped Mesoporous TiO_2 by a Fast Sol-Gel Method

以钛酸丁酯为钛源,尿素为掺杂剂,聚丙烯酰胺(PAM)和聚乙烯醇(PEG)为复合模板剂,采用快速溶胶-凝胶法,并在氮气和空气气氛下连续煅烧,制得高结晶度和高比表面积的氮掺杂介孔TiO_2材料。用X射线衍射(XRD)仪、透射电镜(TEM)、N2吸附-脱附和紫外-可见漫反射光谱等测试手段对所得材料的结构、形貌、粒径、比表面积、孔径以及紫外-可见光吸收性能进行表征。发现当聚丙烯酰胺和聚乙烯醇的质量比为20%和80%时,先在氮气中于873 K煅烧,后在空气中于773 K煅烧所得样品是完全的锐钛矿相、并具有较高的结晶度。粒径、孔径和比表面积分别为大约10~12 nm、17 nm和110 m^2/g。紫外-可见漫反射试验表明与未掺杂介孔TiO_2相比,氮掺杂介孔TiO_2的吸收带明显红移。

N-doped mesoporous TiO_2 with high surface area and high crystallinity was synthesized by a fast sol-gel method using tetrabutyl titanate as the Ti source,urea as the dopant,and polyacrylamide(PAM) and polyethylene(PEG) as the complex templates,and all the samples were calcined in nitrogen and in air successively.XRD,TEM,N_2 adsorption-desorption,and UV-Vis spectroscopy were used to characterize the structure,morphology,crystalline size,specific surface area,pore size,and UV-Vis absorptive property of the as-synthesized materials.It is found that when the proportion of PAM and PEG is20wt%and 80wt%,the sample,prepared at 873 K in nitrogen and at 773 K in air,is complete anatase phase and has high crystallinity.The particle size,pore size,and surface area of the sample are about 10~12 nm,17 nm,and 110 m^2/g,respectively.UV-Vis spectroscopy test indicated that,compared with that of the undoped mesoporous TiO_2,the absorption band edge of N-doped mesoporous TiO_2 exhibits an evident red-shift.