Bi_(3.15)Nd_(0.15)Ti_3O_(12)纳米棒的拉曼和紫外吸收光谱研究

以Bi(NO3)3.5H2O,Nd(NO3)3.6H2O和Ti(OC4H9)4为原料,加入聚乙烯醇(PVA-124),采用水热法在200℃经48 h合成了铋层状钙钛矿结构掺钕钛酸铋(Bi3.15Nd0.85Ti3O12,BNdT)纳米棒,纳米棒直径约10~200 nm,长度达十几微米。利用Raman散射研究了掺钕对钛酸铋晶格结构的影响。掺钕钛酸铋和钛酸铋的Raman光谱表明,Nd取代了类钙钛矿层中A位的Bi,掺Nd改善了BTO的对称性和减小了TiO6八面体的畸变。利用UV-vis光谱研究了BNdT纳米棒的光吸收特性,BNdT纳米棒存在A(400 nm),B(275 nm),C(210 nm),D(196 nm)四个吸收带,分别对应于电子从Bi3+的基态1S0到激发态3P1,3P2,1P1的跃迁和电子从阴离子团TiO6八面体到带正电的Bi3+离子的跃迁。BNdT的带隙为4.3 eV,大的带隙归因于纳米结构的量子尺寸效应。

Study of Raman and UV-vis Spectra of the Bi3.15Nd0.15Ti3O12 Nanorods

The bismuth-layered perovskite Bi3.15Nd0.85Ti3O12(BNdT)nanorods were fabricated via polyvinyl alcohol-assisted hydrothermal method using Bi(NO3)3·6H2O,Nd(NO3)3·6H2O and Ti(OC4H9)4 as the starting materials.The diameters of BNdT nanorods are about 10～200 nm,and the length is about up to 10 μm.The effect of Nd on the lattice structure of bismuth titanate was studied by Raman scattering.The result show the Nd is incorporated into the A site in the perovskite layer of BNdT,and doping Nd can decrease the TiO6 distortion.UV-vis spectra of BNdT nanorods show four absorption bands(A,B,C and D),peaking at 400,275,210 and 196 nm,respectively.A,B and C bands are corresponding to 1S03P1,1S0-3P2 and 1S0-1P1 transition of Bi3+,respectively.And D maybe results from an electron transfer from an anion TiO6 to the positive Bi3+.Moreover,the band energy of BNdT nanorods are 4.3 eV.