Synthesis of layered double hydroxides/graphene oxide nanocomposite as a novel high-temperature CO_2 adsorbent

In this contribution, a novel high-temperature CO_2 adsorbent consisting of Mg-Al layered double hydroxide （LDH） and graphene oxide （GO） nanosheets was prepared and evaluated. The nanocomposite-type adsorbent was synthesized based on the electrostatically driven self-assembly between positively charged Mg-Al LDH single sheet and negatively charged GO monolayer. The characteristics of this novel adsorbent were investigated using XRD, FE-SEM, HRTEM, FT-IR, BET and TGA. The results showed that both the CO_2 adsorption capacity and the multi- cycle stability of LDH were increased with the addition of GO owing to the enhanced particle dispersion and stabilization. In particular, the absolute CO_2 capture capacity of LDH was increased by more than twice by adding 6.54 wt% GO as support. GO appeared to be especially effective for supporting LDH sheets. Moreover, the CO_2 capture capacity of the adsorbent could be further increased by doping with 15 wt% K_2CO_3. This work demonstrated a new approach for the preparation of LDH-based hybrid-type adsorbents for CO2 capture.