3.2. Fourier transform infrared spectroscopy (FTIR) before and after 2-nitroaniline adsorption
The FTIR spectra of carbon before and after 2-nitroaniline adsorption are shown in Fig. 2.
The FTIR spectra of the adsorbent before adsorption indicated the presence of isocyanate (N C O) and amino groups (N H). The peak at 2278 cm-1 was assigned to the stretching bands of isocyanate groups (N C O), and the amino stretch (N H) could be ascribed to the bend that appeared at 3430 cm-1. On the other hand, the peak appeared at 1563 cm-1 was the results of carbonyl groups (C O), and the broad band at 1167 cm-1 that represents haloalkyl groups (C H). From Fig. 2, the peak intensity after adsorption at 3430 cm-1 as well as 2278 cm-1 was slightly lower than that before adsorption, suggesting that the isocyanate and amino groups played an important role in the adsorption.