Synthesis of Cadmium Oxyorthosilicate by a Sol-Gel Method

Cadmium silicates are materials of interest due to their stability and possible application as phosphors. There are three stable forms: cadmium metasilicate, CdSiO₃, cadmium orthosilicate, Cd₂SiO₄ and cadmium oxyorthosilicate, Cd₃SiO₅. Of these, oxyorthosilicate is particularly challenging to obtain, leading to fewer studies. We have successfully prepared Cd₃SiO₅ using a sol-gel approach, employing cadmium acetate and tetraethylorthosilicate as precursors in a stoichiometric proportion of 2:1. Additionally, cetyltrimethylammonium bromide served as a template for creating a mesoporous structure. Adjusting the pH to 3 and subjecting the material to calcination at 800 °C for 6 h, we achieved the formation of cadmium oxyorthosilicate compound, identified by X-ray diffraction. Electron diffractometry and energy dispersive X-ray spectrometry confirm the phase purity. Characterization via nitrogen adsorption analysis and transmission microscopy shows aggregates of nanoparticles with a surface area of 6 m² g 1 and a narrow pore diameter distribution centered at 5 nm.

Keywords:
sol-gel; cadmium oxyorthosilicate; mesoporous; phosphor matrix