Effective preparation of nitrogen-doped activated carbon by aniline thermal chemical vapor deposition for arsenate adsorption

Abstract

Nitrogen-free phenol resin fiber was used to examine the effect of nitrogen-introduction via thermal chemical vapor deposition (CVD) using nitrogen-containing chemicals. In this study, a combination of heat treatment, steam activation, aniline CVD was conducted to prepare the nitrogen-doped activated carbon (AC) and the effective procedure was studied to enhance arsenic adsorption capacity. As a result, consecutive treatment of steam activation as pre-treatment, aniline CVD, steam activation for porous structure, and at least heat treatment was the best processing order for the preparation of ACs. Heat-treated samples demonstrated their robustness against steam activation; therefore heat treatment should be conducted as post treatment for effective CVD process. One of the samples which was prepared by this procedure, 8ST30-8ANL10-8ST50-9.5HT30 (sample #5) showed 0.112 mmol/g of arsenate adsorption capacity, and it was at least 70% higher than that of any other prepared samples. To inspect the high adsorption capacity of this sample, the effect of solution pH, pore structure parameters, elemental analysis, and Boehm titration was conducted comparing with the other prepared samples.