Fe and Ag supported on activated carbon as an effective adsorbent for 2,4-dichlorophenoxylacetic acid treatment: a theoretical study

Abstract

Extended tight-binding quantum chemical method (GFN2-xTB) was performed to investigate the adsorption of 2,4-dichlorophenoxylacetic acid (2,4-D) on activated carbon (AC) and AC modified by Fe or Ag (AC-M). Electronic properties of the studied systems were estimated via vertical ionisation potential, vertical electron affinity, and global electrophilicity index. Adsorption energy, population analysis, and geometrical parameters were calculated to clarify the adsorption ability of AC and AC-M. The results indicated that the introduction of metal atoms to AC substantially enhanced the adsorption ability for 2,4-D. The adsorption mechanism changed from physical adsorption (on AC) to chemisorption (on AC-M). The influence of different solvents (water, methanol, and acetonitrile) on the adsorption process was studied via an Analytical linearized Poisson-Boltzmann algorithm.