Iron oxide nanoparticles (IONPs) were successfully prepared by mixing iron (III) chloride (FeCl₃) salt with henna leaf extract using a simple chemical method with and without applied pulsed laser ablation (PLA) (Nd-YAG). It was found that the bio-molecules inside the henna leaves extract played a significant role in converting the iron salts into IONPs. The PLA technique affected the size, shape, purity, and phases of iron oxide NPs from Fe₂O₃ to FeO. Fe₂O₃ and FeO NPs play a crucial role in the removal of methylene blue (MB) dye in water treatment. IONPs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet (UV–vis), and photoluminescence (PL) spectroscopy. XRD results showed a small crystallite size (50 nm) with hexagonal structure (hematite) forFe₂O₃ NPs without using PLA, while for FeO NPs prepared by PLA, the crystallite size was smaller (24 nm) and the diffraction peaks indicated a cubic structure with excellent crystal quality. SEM showed the grain size of Fe₂O₃ NPs was approximately 69.92 nm, while for the FeO NPs, it was approximately 56.60 nm when PLA was applied. UV–vis measurements indicated a blue shift for the energy gap value from 2.75 eV for Fe₂O₃ NPs eV to 3.3 eV for FeO NPs. PL spectroscopy revealed the band edge emission was approximately 3.57 eV for Fe₂O₃ NPs without PLA, while the band edge emission exceeded 3.63 eV for FeO NPs with PLA application. Moreover, the photocatalytic activity of NPs was demonstrated by the degradation of MB dye under average light irradiation. The results indicate that the synthesized FeO NPs prepared by PLA exhibited higher degradation efficiency, reaching 95 % at 50 min with high photocatalytic activity than the Fe₂O₃ without PLA, for which the degradation efficiency was 88 % at 70 min.

氧化铁纳米颗粒（IONPs）成功地被混合铁（III）氯化物（制备的FeCl ₃使用简单的化学方法具有和不施加脉冲激光烧蚀（PLA）（ND-YAG））盐指甲花叶提取物。研究发现，指甲花叶提取物中的生物分子在将铁盐转化为IONPs方面发挥了重要作用。PLA技术影响了从Fe ₂ O ₃到FeO的氧化铁NP的尺寸，形状，纯度和相。铁₂ O ₃FeO NPs在水处理中去除亚甲基蓝（MB）染料方面起着至关重要的作用。IONP的特征在于X射线衍射（XRD），扫描电子显微镜（SEM），紫外（UV-vis）和光致发光（PL）光谱。XRD结果表明，不使用PLA的Fe ₂ O ₃ NPs的微晶尺寸较小（50 nm），具有六方结构（赤铁矿），而使用PLA制备的FeO NPs的晶粒尺寸较小（24 nm），且衍射峰表明立方具有优良晶体质量的结构。SEM显示Fe ₂ O ₃的晶粒尺寸NPs约为69.92 nm，而FeO NPs在施加PLA时约为56.60 nm。紫外可见测量表明，能隙值从Fe ₂ O ₃ NPs的2.75 eV到FeO NPs的3.3 eV发生了蓝移。PL光谱显示，不带PLA的Fe ₂ O ₃ NP的带边发射约为3.57 eV ，而带PLA的FeO NP的带边发射超过3.63 eV。此外，通过在平均光照射下MB染料的降解证明了NPs的光催化活性。结果表明，由PLA制备的合成FeO NPs具有比Fe ₂ O更高的降解效率，在50min时达到95％，具有较高的光催化活性。₃没有PLA，其70分钟时的降解效率为88％。