Thiazolo[5, 4-d]thiazole based dye modified microspheres as metal nanoparticle reactor template and hybrid catalyst

Abstract

2,5-di(pyridin-4-yl)thiazolo[5,4-d]thiazole (Py2TTz) molecule was synthesized and used to modify poly(4-vinyl benzylchloride) microparticles (PVBC-MPs) thanks to its superior interaction with 4-vinyl benzyl chloride monomer containing active –Cl atom. PVBC spherical microparticles were successfully synthesized by suspension polymerization method and they were modified via two different approaches as in-situ and post-modification. Monodispersity of particles via in-situ modification is a challenging approach due to the low solubility of Py2TTz. Therefore, post-modification of PVBC microparticles with Py2TTz dye was carried out. The particles act as metal nanoreactor in the absence of any reducing agent both at room temperature and 50 °C. The particle morphology was determined with electron microscopies before and after reduction process. Metal nanoparticles (MNP) on MPs were characterized via XRD analysis. Gold, silver and platinum nanoparticles (AuNP, AgNP and PtNP) decorated microparticles were successfully synthesized. According to the ICP-MS results, 25.6% Ag, 24.7% Pt and 0.33% Au were found in the microparticles treated with metal cations. These MNP decorated MPs were used as hybrid heterogeneous catalyst for 4-nitrophenol reduction into 4-aminophenol. The highest catalytic efficiency was obtained with AgNPs decorated MPs as also consistent with the ICP-MS data. The catalytic activities of the MNP decorated MPs were determined with time dependent absorption measurents via UV–Vis spectrophotometer.