Metal Removal by Sodium Graphene Oxide

Graphene oxide (GO) is a phenomenal nano-adsorbent for heavy metal cations; however, its acidic properties limit its practical application. This study investigated the adsorption behavior of neutralized graphene oxide, herein referred to as sodium graphene oxide (SGO). Titration data revealed that the preparation of SGO did not alter the surface sites of GO. An equilibrium derived model was used to estimate the amount of base needed to neutralize GO and gave an excellent approximation of the total number of sites on GO. Adsorption experiments and the subsequent Langmuir modeling showed SGO to have a maximum adsorption capacity for lead of 910 (mg g-1) surpassing that of every known carbon adsorbent. This study shows that SGO retains GO excellent adsorption capabilities without caustic conditions.