UC Irvine

Highly efficient capture technologies used to mitigate CO2 emissions have directed the search for alternative methods with low energy consumption rates. There is an estimated 80% increase in energy cost to operate current CO2 capture technologies. In view of that, while most work is aimed at chemical means to reduce this energy cost, we seek to harness solar energy to improve current CO2 capture solvent desorption efficiency. Recently, we reported a new method to release CO2 from solutions using solar energy to drive localized photothermal heating. Photothermal release of CO2, addresses the high-energy costs associated with regenerating capture fluids. By incorporating light absorbing nanoparticles into the capture fluid and irradiating with light, 80% of the incident light energy is used in CO2 release, rather than heating the bulk fluid. In addition to this work, we sought to understand how the mechanism of photothermal release enhances the efficiency of this process. Through covalent modification of the surface, we explore how surface charge and polarity of the nanoparticles influence the photothermal regeneration of a CO2 capture nanofluid through decarboxylation. By incorporating sulfonamides on the surface of CB, we enhanced the photothermal separation of CO2 from monoethanolamine by approximately 70% more than the unmodified CB.