Fluorescence quenching on mesoporous carbon nitride by phenol and aniline

Abstract

In this study, fluorescence quenching on mesoporous carbon nitride (MCN) was examined in the presence of phenol and aniline. The MCN was synthesized by thermal polymerization of cyanamide using nanocolloidal silica (7 nm) as a hard template and characterized by X-ray diffractometer (XRD), Fourier transform infrared (FTIR), transmission electron microscope (TEM), specific surface area, pore size distribution, and fluorescence spectrophotometer. The MCN showed two excitation wavelengths at 275 and 370 nm, owing to the presence of N=C and N-C terminal groups, respectively. These two excitation wavelengths gave only one emission peak at around 460 nm. Either in the presence of phenol or aniline, the emission intensity of the MCN was confirmed to be quenched in a linear function towards the concentration of phenol or aniline as the quencher molecule. N-C terminal groups were found to have slightly better interactions to phenol and aniline as compared to the N=C groups. Since the emission intensity of MCN was more quenched by phenol molecules than the aniline, it was proposed that the MCN would have stronger interaction to phenol than aniline. This result was also supported by the adsorption data, in which the MCN gave higher adsorption towards phenol than the aniline.