Islam Md Rafiqul, Zubair M A, Bashar M S, Rashid A K M B
Department of Materials and Metallurgical Engineering, Bangladesh University of Engineering & Technology, Dhaka, 1000, Bangladesh.
Department of Glass and Ceramic Engineering, Bangladesh University of Engineering & Technology, Dhaka, 1000, Bangladesh.
Sci Rep. 2019 Mar 26;9(1):5205. doi: 10.1038/s41598-019-41570-x.
A visible light active BiHoFeO nanoparticles/TiO composite thin films with different mol.% of BiHoFeO were successfully prepared via non-aqueous sol-gel method. The incorporation of 5, 10 and 20 mol.% BiHoFeO nanoparticles in the precursor solution of TiO brings modifications in the functional properties of the composite thin films. XPS analysis indicates that interdiffusion of Fe, Ho, Bi/Ti ions through the interfaces between BiHoFeO nanoparticles and TiO matrix reduces the concentration of Ti ions. X-ray diffraction analysis affirms that TiO and BiHoFeO retain anatase and orthorhombic phase respectively in composite films. The composite thin film containing 20 mol.% BiHoFeO nanoparticles exhibits the most prominent absorption phenomenon in visible region and has significantly reduced indirect band gap of 2.46 eV compared to that of pure TiO (3.4 eV). Hall effect measurements confirm that the resistivity of composite film increases by ∼2.33 orders of magnitude and its carrier concentration decreases by 1.8 orders of magnitude at 5 mol.% BiHoFeO nanoparticles addition compared to those of pure TiO film. Moreover, the pure film exhibits diamagnetism, whereas the composite films have both large ferromagnetic and small diamagnetic components. The findings in this research justify that the composite film can be a potential candidate for making improved photocatalyst, resistors and spintronic devices.
通过非水溶胶 - 凝胶法成功制备了具有不同摩尔百分比BiHoFeO的可见光活性BiHoFeO纳米颗粒/TiO复合薄膜。在TiO前驱体溶液中掺入5%、10%和20%摩尔的BiHoFeO纳米颗粒会使复合薄膜的功能特性发生改变。XPS分析表明，Fe、Ho、Bi/Ti离子通过BiHoFeO纳米颗粒与TiO基体之间的界面相互扩散，降低了Ti离子的浓度。X射线衍射分析证实，在复合薄膜中TiO和BiHoFeO分别保持锐钛矿相和正交相。含有20%摩尔BiHoFeO纳米颗粒的复合薄膜在可见光区域表现出最显著的吸收现象，并且与纯TiO（3.4 eV）相比，其间接带隙显著降低至2.46 eV。霍尔效应测量证实，与纯TiO薄膜相比，在添加5%摩尔BiHoFeO纳米颗粒时，复合薄膜的电阻率增加了约2.33个数量级，其载流子浓度降低了1.8个数量级。此外，纯薄膜表现出抗磁性，而复合薄膜同时具有大的铁磁分量和小的抗磁分量。本研究结果表明，该复合薄膜有望成为制备改进型光催化剂、电阻器和自旋电子器件的潜在候选材料。
