▎ 摘　　要

Hydrate-based CO2 capture and sequestration (CCS) has been viewed as a promising technology to control CO2 in the atmosphere; achieving rapid formation and high storage capacity of CO2 hydrates is critical for utilizing this technology. Sodium dodecyl sulfate (SDS) has been confirmed as the most efficient promoter for CH4 hydrate formation, but the promotion of CO2 hydrate formation by SDS is very poor. Therefore, developing exclusive and efficient promoters for CO2 hydrate formation is crucial for achieving hydrate-based CCS. In this study, we used graphene nanosheets as carriers and grafted -SO3- groups (similar to the hydrophilic group of SDS) and Ag nanoparticles of about 2-5 nm on nano-carriers to prepare a novel promoter (named as Ag@SGO), which could overcome the limitations of SDS and improve its promotion efficiency. When 1 mmol L-1 (0.288 g L-1) SDS was used as the promoter, CO2 hydrate formation lasted over 1000 min and the gas consumption reached merely 2.90 +/- 0.22 mmol mL(-1) water at 1000 min, clearly denoting poorer promotion compared with the promotion of CH4 hydrate formation, in which hydrate formation was completed within several hours with the gas consumption reaching 6-7 mmol mL(-1) water. However, when Ag@SGO was applied at 0.25 g L-1, majority of the CO2 hydrate formation was finished at 200-250 min and the gas consumption reached 7.62 +/- 0.16 mmol mL(-1) water at 1000 min, which was almost 2.6 times as that with SDS. This indicated that graphene-carried -SO3- and nano-Ag developed in this study produced particularly efficient promotion of CO2 hydrate formation and therefore, they exhibit significant potential for the industrial application of hydrate-based CCS.