A comparative study of the synthesis and cathodoluminescence of BiOCl nanostructures using synthetic tannins

Bismuth oxychlorides (BiOCl) nanostructures have attracted much attention due to their physicochemical properties with applications in pharmaceuticals and electronics; hence, its efficient production is considered to be of great importance. In this regard, polyphenols have emerged as excellent growth directing agents for the synthesis of nanomaterials, representing a soft and cleaner alternative for their controlled production. In this work, we compared the efficiencies of two synthetic tannins, tannic and gallic acid, for the soft chemistry production of BiOCl nanoflakes at room temperature. The morphology, chemical composition, and crystal structure of the produced nanocompounds were determined and compared in both cases. One phase BiOCl nanoflakes were produced when tannic acid was used, while a mixture of BiOCl and Bi2O3 phases was present in case of using gallic acid. The results reveal a phase stabilizing role of the glucose core present in tannic acid compared to gallic acid. Finally, optical absorption measurements revealed the band gap tuning of the produced nanostructures, and blue emission was observed through cathodoluminescence measurements in the 350−450 nm region.