Abstract

Abstract
The onion-like carbon (OLC) was prepared as adsorbent and tested for the removal of chromate ionsfrom aqueous solutions. The OLC was thermally derived from nanodiamond by vacuum annealing at1000–2000◦C. An investigation was conducted the chromate adsorption mechanism of OLC, by analysingthe temperature-dependent evolution of the various oxygen-carbon bonds and the chemisorbed waterby X-ray photo electron spectroscopy, as well as by the first principle calculation of the bond energiesfor relevant bond configurations. The present work demonstrated the importance of the carbon-oxygenbond type and carbon dangling bonds for chromate adsorption, as well as for other anionic heavy metalsadsorbed from wastewater and sewage.