Khanam Juliya, Hasan Md Rashib, Biswas Bristy, Ahmed Md Farid, Mostofa Sabrina, Akhtar Umme Sarmeen, Hossain Md Kamal, Quddus Md Saiful, Ahmed Samina, Sharmin Nahid, Al-Reza Sharif Md
Institute of Glass and Ceramic Research and Testing (IGCRT), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, 1205, Bangladesh.
Department of Applied Chemistry and Chemical Engineering, Islamic University, Kushtia, Bangladesh.
Heliyon. 2024 Dec 6;10(24):e41030. doi: 10.1016/j.heliyon.2024.e41030. eCollection 2024 Dec 30.
Hematite (α-FeO) nanoparticles have been synthesized from waste source of iron which contains a prominent amount of iron (93.2 %) and investigated the effect of low temperature calcination. The two-step synthesis method involved preparing ferrous sulfate through acid leaching process followed by oxidation and calcination at temperatures ranging from 200 to 400 °C to produce the desired α-FeO in nano form. The structure, size and morphology of the hematite nanoparticles were characterized using various instrumental techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Fourier transformed infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (DRS), and a nanoparticle size analyzer. Hematite single phase was confirmed by XRD and the phase occurred at 200 °C might indicate the stability range of hematite under certain condition. The average crystal sizes were determined using Debye Scherer formula, modified Scherer formula, size strain plot equation and Halder-Wagner-Langford's method and the results show that crystallite sizes decreased with increasing calcination temperature. XPS analysis confirmed the chemical state (Fe) and surface chemistry of the hematite nanoparticles calcined at 300 °C. Raman spectrum also supported that the nanoparticles were complete hematite phase and the intensity of all the features decreased with increasing calcination temperature which are consistence with the result obtained from XRD pattern. FTIR spectra of the samples also confirms the XRD results. Morphological analysis obtained from SEM and TEM images suggested the agglomerated irregular spherical nanoparticles with grain size 13.49 nm calcined at 300 °C. Band gap energy of the samples were calculated from DRS data and the values ranging from 2.30 to 2.42 eV which are slightly higher than the bulk (∼2.1eV). Particles size analysis have been carried out using DLS and Z-average particle size and poly dispersity index (PDI) were measured which indicate the particles are nearly same size (220-226 nm).
赤铁矿（α-Fe₂O₃）纳米颗粒由含铁量高（93.2%）的铁废料合成，并研究了低温煅烧的影响。两步合成法包括通过酸浸过程制备硫酸亚铁，随后在200至400℃的温度范围内进行氧化和煅烧，以制备所需的纳米级α-Fe₂O₃。使用包括X射线衍射（XRD）、X射线光电子能谱（XPS）、拉曼光谱、傅里叶变换红外（FTIR）光谱、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、紫外可见漫反射光谱（DRS）和纳米颗粒尺寸分析仪等各种仪器技术对赤铁矿纳米颗粒的结构、尺寸和形态进行了表征。XRD证实了赤铁矿单相，在200℃出现的相可能表明赤铁矿在一定条件下的稳定范围。使用德拜-谢乐公式、修正的谢乐公式、尺寸应变图方程和哈尔德-瓦格纳-兰福德方法测定了平均晶体尺寸，结果表明晶粒尺寸随煅烧温度的升高而减小。XPS分析证实了在300℃煅烧的赤铁矿纳米颗粒的化学状态（Fe）和表面化学性质。拉曼光谱也支持纳米颗粒为完整的赤铁矿相，并且所有特征的强度随煅烧温度的升高而降低，这与XRD图谱得到的结果一致。样品的FTIR光谱也证实了XRD结果。从SEM和TEM图像获得的形态分析表明，在300℃煅烧的团聚不规则球形纳米颗粒的粒径为13.49nm。根据DRS数据计算了样品的带隙能量，其值在2.30至2.42eV之间，略高于体相（约2.1eV）。使用动态光散射（DLS）进行了颗粒尺寸分析，测量了Z平均粒径和多分散指数（PDI），结果表明颗粒尺寸几乎相同（220-226nm）。
