Preparation of LiNbO₃ nanoparticles using poly(l-lysine) as a biomolecular additive

The effects of poly(l-lysine) as a biomolecular additive on the synthesis of LiNbO₃ were investigated. PLL is a widely-studied biomolecule containing amino groups that can interact with solid inorganic clusters. The addition of PLL to a LiNbO₃ precursor solution enhanced the aggregation of the produced LiNbO₃ nanoparticles. This aggregation was induced by the electrical attraction of PLL with LiNbO₃ nanoparticles, and was enhanced with increasing PLL molecular weight. Furthermore, the association of PLL with LiNbO₃ nanoparticles was increased by the addition of methanol, which enhanced the miscibility of PLL with the precursor solution working as a co-solvent. The LiNbO₃ nanoparticles generated with PLL exhibited piezoelectric properties without post-thermal treatment, suggesting that PLL contributes to the piezoelectricity. The results of this study are intriguing in terms of the potential for diverse engineering nanomaterials synthesis through a biomolecule that can also improve the physicochemical properties.