The aim of this work is to optimize the synthesis parameters involved in the green synthesis of zinc oxide (ZnO) nanoparticles using banana peel (BP) extract as reducing and capping agents. The UV–vis spectra of biosynthesized ZnO exhibited a strong absorption peak at 344 nm with a band gap of 2.95–3.14 eV. FTIR analysis revealed the presence of biomolecules on the synthesized ZnO nanoparticles. XRD results proved that the purity of the prepared ZnO nanoparticles was pH dependent with size of 30−80 nm when determined by the Debye–Scherrer equation. SEM images also revealed different ZnO morphologies were formed depending on the pH of the synthesis conditions. The samples exhibited red photoluminescence emission in the visible region. According to the results, the best conditions for the synthesis of ZnO nanoparticles were pH = 12, 1 mL BP extract, 0.02 M zinc acetate dihydrate, 3 h synthesis time, and 60 °C temperature. The synthesized ZnO nanoparticles displayed good visible-light photocatalytic activity for the reduction of methylene blue (MB). The optimized biosynthesized ZnO showed reusability for 4 catalytic cycles.

这项工作的目的是优化使用香蕉皮（BP）提取物作为还原剂和加帽剂进行绿色合成氧化锌（ZnO）纳米粒子所涉及的合成参数。生物合成的ZnO的紫外可见光谱在344 nm处显示出很强的吸收峰，带隙为2.95–3.14 eV。FTIR分析表明在合成的ZnO纳米颗粒上存在生物分子。XRD结果证明，由Debye-Scherrer方程确定时，制备的ZnO纳米颗粒的纯度与pH值有关，大小为30-80 nm。SEM图像还显示，取决于合成条件的pH，形成了不同的ZnO形态。样品在可见光区域显示红色光致发光。根据结果​​，合成ZnO纳米颗粒的最佳条件是pH = 12、1 mL BP提取物，0.02 M醋酸锌二水合物，合成时间3小时，温度60°C。合成的ZnO纳米粒子具有良好的可见光光催化活性，可还原亚甲基蓝（MB）。优化的生物合成ZnO在4个催化循环中显示出可重复使用性。