A green chemical method for synthesis of ZnO nanoparticles from solid-state decomposition of Schiff-bases derived from amino acid alanine complexes

As a part of the desire to save the environment via green chemistry practices, we report a novel method to synthesize ZnO nanoparticles from nontoxic and biocompatible chemicals where no pollutant or combustible side product is produced. In this recipe, a binary Zn(II) Schiff-base complex is obtained from alanine where water is used as solvent and a biologically compatible amino acid instead of toxic amines is used as a nitrogen source. The Schiff-base complex is subsequently heat treated to synthesize ZnO particles via a solid-state decomposition process. The effect of post heat treatment temperature (400, 500, and 600 °C) on microstructure and defect content of ZnO nanoparticles is investigated. The formation of single phase ZnO particles is confirmed by XRD θ-2θ patterns and FTIR spectra. TEM and SEM micrographs indicate the formation of nanoparticles with a particle size of 50-110 nm for different heat treatment temperatures. Combing XRD, FTIR, and PL results, it is revealed that the samples heat treated at intermediate temperatures (500 °C) possess the lowest defect concentration and a favorable crystallinity. This study emphasizes on green chemistry and synthesis of nanomaterials through ecofriendly methods to save our planet and its reservoirs for future and next generations.