An eco-friendly method for the synthesis of ZnO nanoparticles was studied. Zinc acetate precursor was thermally decomposed without adding any chemical agents. The synthesized materials were thoroughly characterized by various analytical tools. The results indicated that the synthesized ZnO nanomaterials have a wurtzite structure. The estimated crystallite sizes of the materials obtained at 450, 550, 650, and 750°C (named as ZnO-450, ZnO-550, ZnO-650, and ZnO-750) were 33, 36, 38, and 42 nm, respectively. The morphology of the nanomaterials was revealed to be affected by calcination temperature, causing the formation of both nanoparticles and nanorods with different sizes and shapes. The materials were applied as photocatalysts for methylene blue (MB) decomposition under ultraviolet (UV) light. Results showed that the decomposition efficiency strongly depends on UV illumination time, size, and morphology of ZnO nanomaterials. The highest MB decomposition (99.4%) is obtained when using ZnO-750. The photocatalytic decomposition follows the first-order reaction. The reaction rate constants corresponding to the MB decomposition process with the presence of ZnO-450, ZnO-550, ZnO-650, and ZnO-750 are 0.0512, 0.0636, 0.1077, and 0.1286 min^-1, respectively.

中文翻译：

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绿色，非化学路线制备的ZnO纳米材料的合成，表征和光催化活性

研究了一种环保的ZnO纳米粒子的合成方法。乙酸锌前体在不添加任何化学试剂的情况下被热分解。合成的材料通过各种分析工具进行了全面表征。结果表明，合成的ZnO纳米材料具有纤锌矿结构。在450、550、650和750°C下获得的材料（称为ZnO-450，ZnO-550，ZnO-650和ZnO-750）的估计微晶尺寸为33、36、38和42 nm，分别。揭示了纳米材料的形态受煅烧温度的影响，导致形成具有不同尺寸和形状的纳米颗粒和纳米棒。将该材料用作光催化剂，用于在紫外（UV）光下分解亚甲基蓝（MB）。结果表明，分解效率在很大程度上取决于ZnO纳米材料的紫外线照射时间，大小和形态。使用ZnO-750时，可获得最高的MB分解率（99.4％）。光催化分解遵循一级反应。与存在ZnO-450，ZnO-550，ZnO-650和ZnO-750的MB分解过程相对应的反应速率常数为0.0512、0.0636、0.1077和0.1286分钟^-1。