Performance enhancement of CO2 capture adsorbents by UV treatment: The case of self-supported graphene oxide foam

Development of novel and more efficient materials for capturing CO2 from various sources is of high priority as to combat the climate change effects due to increasing CO2 levels in the atmosphere. In this work, a UV-irradiated graphene oxide foam (UV-GOF) was developed and studied for CO2 adsorption. The characteristics of the prepared GOF and UV-GOF adsorbents related to structure, morphology, and surface properties were obtained, while methylene blue dye adsorption was used as efficient means to evaluate their specific surface area. CO2 adsorption performance was evaluated in terms of capacity, selectivity, regenerability, kinetics, isosteric heat of sorption, and hydrophilicity. UV treatment and the associated structural and surface changes on the developed GOF were found to impact adsorption performance, and optimum conditions were extracted. Indicatively, a 30-fold higher selectivity was obtained at 100 mbar upon 5-h UV treatment with an associated 7-fold increase in CO2 capacity. UV treatment of graphene-based adsorbents can enhance performance for carbon capture that can be potentially applied at industrial scale before capture application as a facile and low-cost pretreatment technology.