OICC Press International Nano Letters 2228-5326 15 1 2025 03 31 Zinc oxide nanoparticles assembling by a green chemistry method 10.57647/inl.2025.1401.03 EN Adrien Bonneau Université de Toulon, Aix Marseille Univ., CNRS, IM2NP, Toulon, France https://orcid.org/0009-0004-2628-3069 Marie-Angèle Frémy Université de Toulon, Aix Marseille Univ., CNRS, IM2NP, Toulon, France Sylvie Villain Université de Toulon, Aix Marseille Univ., CNRS, IM2NP, Toulon, France https://orcid.org/0000-0003-0021-209X Gilles Baratto Véolia Eau, Var Provence Méditerranée, La Garde, France Vincent Cot Véolia Eau, Var Provence Méditerranée, La Garde, France La Garde, France Patricia Merdy Université de Toulon, Aix Marseille Univ., CNRS, IM2NP, Toulon, France https://orcid.org/0000-0002-4540-6464 Journal Article 2025 03 31 Zinc oxide is a semiconductor material with an interesting potential for photocatalysis of organic pollutants. It has been prepared according an eco-friendly green method, using five various plant extracts (banana, rosemary, bitter orange, olive tree, comfrey). Two different synthesis processes were tested: a hotplate synthesis and a hydrothermal method. Metal precursor used was zinc acetate. Plants present in the process allowed the formation and the self-assembling of ZnO during the crystal growth thanks to the large chemical family of polyphenol which act as reductants. Crystalline and organic matter-free compounds obtained after annealing were characterized with diffractive reflectance spectroscopy (DRS) to determine gap energies and confirm ZnO belonging to semiconductors, X-ray diffraction to verify the crystalline structure and its features, Fourier transform infrared spectroscopy (FTIR) to check the characteristic functional group and scanning electron microscopy (SEM) to reveal the self-assembling forms of ZnO. Data about the shapes, dimensions and crystal planes of zinc oxide were regarded in the light of the plant and the synthesis method used. This work has highlighted the morphologies of ZnO obtained on the basis of the synthesis method and the plant extracts. Highlight Zinc oxide has been synthesized by a green process using several plant extracts. Hotplate and hydrothermal synthesis methods were compared in terms of ZnO properties. SEM observations of the various ZnO powders obtained showed great variations in morphologies. The ZnO variabilities obtained were the result of the plant used rather than the synthesis method used. XRD and gap energy measured are quite similar whatever the plant extract.