Biosynthesis of nanoparticles is ecofriendly, cost effective and safer than the physical and chemical methods of fabrication of nanoparticles. Phoenix dactylifera (Date palm) was used for the fabrication of Cobalt (II) oxide nanoparticles. The produced cobalt oxide nanoparticles were characterized using UV visible absorption spectroscopy, FTIR, XRD, Scanning Electron Microscopy, particle size and zeta potential measurements. The UV visible absorption spectrum of the produced cobalt (II) oxide nanoparticles revealed a peak at 530 nm. SEM image showed the agglomeration of particles, which were spherical with the mean size of ~ 80 nm. The produced cobalt (II) oxide nanoparticles showed a zeta potential value of − 30.8 mV. The antimicrobial property of different concentrations of the produced cobalt oxide nanoparticles was examined. The results showed the cobalt (II) oxide nanoparticles having a good antibacterial activity against both gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative bacteria (Klebsiella pneumoniae and Escherichia coli). The fabricated cobalt oxide nanoparticles also showed better antifungal activity against Aspergillus niger. Photocatalytic activity of the synthesized cobalt oxide nanoparticle was determined by the decreasing concentration of Congo red dye and the results showed better degradation of 92.45% after 70 min under solar radiation. Thus, the present study has revealed that the cobalt oxide nanoparticles can be synthesized using P. dactylifera seed extract in a cost effective and ecofriendly manner and can be used for photocatalytic and antimicrobial applications.

纳米粒子的生物合成比制造纳米粒子的物理和化学方法更环保、具有成本效益且更安全。凤凰指尖（枣椰树）用于制造钴（II）氧化物纳米颗粒。使用紫外可见吸收光谱、FTIR、XRD、扫描电子显微镜、粒度和zeta电位测量来表征产生的氧化钴纳米颗粒。所生产的氧化钴 (II) 纳米粒子的紫外可见吸收光谱显示在 530 nm 处有一个峰值。SEM 图像显示颗粒的团聚，它们是球形的，平均尺寸约为 80 nm。所生产的氧化钴 (II) 纳米粒子的 zeta 电位值为 - 30.8 mV。检测了不同浓度所生产的氧化钴纳米颗粒的抗菌性能。结果表明，氧化钴（II）纳米粒子对革兰氏阳性菌（枯草芽孢杆菌和枯草芽孢杆菌）均具有良好的抗菌活性。金黄色葡萄球菌）和革兰氏阴性菌（肺炎克雷伯菌和大肠杆菌）。制备的氧化钴纳米颗粒还显示出更好的抗黑曲霉抗真菌活性。合成的氧化钴纳米颗粒的光催化活性由刚果红染料浓度的降低决定，结果表明在太阳辐射下 70 分钟后降解率达到 92.45%。因此，本研究表明，氧化钴纳米颗粒可以使用P. dactylifera种子提取物以具有成本效益和生态友好的方式合成，并可用于光催化和抗菌应用。