Obtenção de carbonos mesoporosos funcionalizados para aplicação em sensores eletroquímicos na detecção de contaminantes emergentes

Abstract

The mesoporous silica SBA-15 was synthesized through hydrothermal method and used as template for the synthesis of the mesoporous carbon, CMK3, through nanocasting route. The synthesized materials kept the hexagonal pore structure. The CMK-3 was organofunctionalized using maleic anhydride and reducing reagents in order to generate carboxylic groups and to cause its reduction, forming the sample labeled as CMK-3RED. Both synthesis and modification of mesoporous carbons were proven by X-ray Diffractometry (XRD), thermogravimetry (TG), Raman spectroscopy and Scanning Electron Microscopy (SEM). The XRD spectra confirm that the carbonaceous material CMK-3 kept the same structure morphology of SBA-15, confirmed by the SEM images. The CMK3RED had morphology alteration due to its chemical functionalization, which was confirmed by XRD, SEM and TG. The application of these materials was in electrochemistry. In the electroanalysis of caffeine and salicylic acid analytes was used a glassy carbon electrode, which was modified through drop casting method with the mesoporous carbons CMK-3 and CMK-3RED with a concentration of 2 mg of sample in 1 ml of solvent. The differential pulse voltammetry showed that the modified electrode with the CMK-3 sample had better results, with a detection limit of 8,86% to 24,99% better than the unmodified electrode.