An Overview on the Different Approaches to Obtain Luminescent Hydrotalcite Nanoparticles and Films

Hydrotalcite-like compounds (HTlc) are the only layered materials with positively charged layers and exchangeable interlayer anions. Their tunable layered charge density and chemical composition make HTlc versatile materials suitable for a wide range of applications such as fillers of polymeric nanocomposites, pharmaceutics, adsorbents and catalysts. In this short review we report an overview on some methods used to prepare luminescent HTlc nanoparticles and films. First we focused on the most common intercalation process based on the insertion of anionic dyes species in the interlayer region of HTlc, then two more recent approaches, aimed to modify only the HTlc layers, are presented. Specifically, we review the silylation with organic dyes, a method which exploits the OH groups of HTlc, and the insertion of lanthanide cations in place of Al(III) into the HTlc layer. The possibility to obtain luminescent HTlc in form of nanoparticles and films by using different approaches highlights the potential use of these nanostructured materials in important applications ranging from diagnostic biomedical tools to photonics, sensing and opto-electronic devices.