Hierarchical copper oxide (CuO) microspheres were prepared by Moringa oleifera (M. oleifera) leaf extract assisted green synthesis method. The structural, chemical, and morphological features of the hierarchical CuO microspheres were inspected by XRD, FTIR, SEM, and EDAX techniques. The XRD pattern unveiled the formation of monoclinic crystal structured CuO, which confirmed the conversion of Cu(NO₃)₂.3H₂O to Cu²⁺ ions by phytochemicals present in the M. oleifera leaf extract. The SEM micrographs demonstrated that small CuO nanostructures have interacted with adjacent CuO nanostructures leading to the formation of cluster-like morphologies that resemble hierarchical CuO microspheres. The asymmetric stretching deformation vibration bands observed in the FTIR spectrum of the hierarchical CuO microspheres correspond to Cu–O bond along the (−2 0 2) direction that conveyed monoclinic unit crystal formation of the CuO. The detected Cu and O elements through the EDAX analysis reveal the pristine nature of the hierarchical CuO microspheres. The rich phytochemicals in the M. oleifera leaf extract played crucial roles towards the formation and stabilization of hierarchical CuO microspheres. The highest bactericidal activity was noticed against the Staphylococcus aureus strain with zone of inhibition (ZOI) of 30 and 32 mm for the hierarchical CuO microspheres dosage of 50 and 100 μL, respectively, followed by Klebsiella pneumoniae, Escherichia coli and Bacillus cereus strains. The better bactericidal activity observed against the selected bacterial strains could be credited to ideal interaction of the hierarchical CuO microspheres/small nanostructures with cell walls of the bacterial strains, favorable deliverance of copper ions inside the cells and subsequent production of reactive oxygen species.

分级氧化铜（CuO）的微球通过制备辣木（辣木）叶提取物辅助的绿色合成方法。通过XRD，FTIR，SEM和EDAX技术检查了CuO分层微球的结构，化学和形态特征。X射线衍射图揭示了单斜晶结构的CuO的形成，这证实了油分枝杆菌中存在的植物化学物质将Cu（NO ₃）₂ .3H ₂ O转化为Cu ²⁺离子。叶提取物。SEM显微照片表明，小的CuO纳米结构已经与相邻的CuO纳米结构相互作用，从而导致形成类似于分层CuO微球的簇状形态。在分层CuO微球的FTIR光谱中观察到的不对称拉伸变形振动带对应于沿（-2 0 2）方向的Cu-O键，该键传递了CuO的单斜晶单元晶体形成。通过EDAX分析检测到的Cu和O元素揭示了分层CuO微球的原始性质。油茶叶片提取物中的丰富植物化学物质对分层CuO微球的形成和稳定起着关键作用。最高的杀菌活性是针对CuO微球剂量分别为50和100μL时，抑制区（ZOI）分别为30和32 mm的金黄色葡萄球菌菌株，其次是肺炎克雷伯菌，大肠杆菌和蜡样芽胞杆菌。观察到的针对所选细菌菌株的更好的杀菌活性可以归因于分层的CuO微球/小的纳米结构与细菌菌株的细胞壁的理想相互作用，细胞内铜离子的有利传递以及随后产生的活性氧。