|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals, and Materials
||LL-54: Significance of Graphitic Surfaces in Aurodicyanide Adsorption by Activated Carbon: Experimental & Computational Approach
||Dhiman Bhattacharyya, Tolga Depci, Keith Prisbrey, Jan D Miller
|On-Site Speaker (Planned)
Despite tremendous developments in industrial use of activated carbon (AC) for gold adsorption, specific aurodicyanide [Au(CN)<sub>2</sub><sup>-</sup>] adsorption sites on the carbon have intrigued researchers. The graphitic structure of AC had been established. XPS, radiochemical, and Raman characterizations demonstrated higher site-specific gold adsorption on graphitic edges. SEM, HRXMT, and BET analysis revealed large distribution of micro and mesopores, while TEM showed slit-pore (5-10 Å) morphology. Molecular-dynamics-simulation performed on graphitic slit-pores illustrated gold-cyanide ion-pair preferentially adsorbs on edges. Ab-initio simulations predicted lower barrier for electron sharing in pores with aurodicyanide, indicating tighter bonding than graphitic surface. Interaction energy as function of the separation distance indicated tighter bonding of gold cyanide to the graphite edges than water molecules. Gibbs energy calculations provided evidence that gold-cyanide has favorable bonding tendency within narrow slit-pore. Selective adsorption of aurodicyanide ion-pair seems to be related to low polarity of gold complex and its accommodation at graphitic edges.
||Planned: A print-only volume