Kolhar Priyanka, Sannakki Basavaraja, Verma Meenakshi, S V Prabhakar, Alshehri Mansoor, Shah Nehad Ali
Department of Physics, Gulbarga University, Kalaburgi 585106, India.
University Centre for Research and Development, Chandigarh University, Gharuan, Mohali 160055, India.
Nanomaterials (Basel). 2023 Jul 31;13(15):2223. doi: 10.3390/nano13152223.
Nickel ferrite nanoparticles are prepared by using a low-temperature self-propagating solution combustion method using urea as fuel. The prepared nickel ferrite nanoparticles were doped with polyaniline in the three different weight ratios of 10%, 30% and 50% by using an in situ polymerization method and by adding ammonium persulfate as an oxidizing agent. The obtained samples were characterized by using XRD, FTIR, SEM and a UV-visible spectrophotometer. XRD examined crystalline peaks of ferrites and amorphous peak of polyaniline and confirmed the formation of the composites. FTIR examined the chemical nature of samples and showed peaks due to polyaniline and the characteristic peaks that were less than 1000 cm wavenumber were due to metal-oxygen bond vibrations of ferrites. AC conductivity increased with frequency in all samples and the highest AC conductivity was seen in polyaniline/nickel ferrite 50%. DC conductivity increased in all samples with the temperature showing the semiconducting nature of the samples. Activation energy was evaluated by using Arrhenius plots and there was a decrease in activation energy with the addition of ferrite content. The UV-visible absorption peaks of polyaniline showed shifting in the composites. The optical direct and indirect band gaps were evaluated by plotting Tauc plots and the values of the optical band gap decreased with addition of ferrite in polyaniline and the Urbach energy increased in the samples with 10%, 30% and 50% polyaniline/nickel ferrite composites. The optical properties of these composites with a low band gap can find applications in devices such as solar cells.
镍铁氧体纳米颗粒通过使用尿素作为燃料的低温自蔓延溶液燃烧法制备。采用原位聚合法并添加过硫酸铵作为氧化剂，将制备的镍铁氧体纳米颗粒与聚苯胺以10%、30%和50%三种不同的重量比进行掺杂。使用X射线衍射仪（XRD）、傅里叶变换红外光谱仪（FTIR）、扫描电子显微镜（SEM）和紫外可见分光光度计对所得样品进行表征。XRD检测了铁氧体的结晶峰和聚苯胺的非晶峰，并证实了复合材料的形成。FTIR检测了样品的化学性质，显示出聚苯胺的峰以及波数小于1000 cm的特征峰是由于铁氧体的金属-氧键振动。所有样品的交流电导率均随频率增加，在聚苯胺/镍铁氧体50%中观察到最高的交流电导率。所有样品的直流电导率随温度升高，表明样品具有半导体性质。通过使用阿伦尼乌斯图评估活化能，随着铁氧体含量增加活化能降低。聚苯胺的紫外可见吸收峰在复合材料中发生了位移。通过绘制陶克图评估光学直接和间接带隙，随着聚苯胺中铁氧体的添加，光学带隙值降低，在10%、30%和50%聚苯胺/镍铁氧体复合材料的样品中乌尔巴赫能量增加。这些具有低带隙的复合材料的光学性质可应用于太阳能电池等器件。
