Tailoring and properties of a novel solar energy-triggered regenerative bionic fiber adsorbent for CO2 capture

Using renewable solar energy sources instead of heat energy to desorb CO2 from adsorbents is a promising strategy for reducing the energy consumption of adsorbent regeneration. However, the photothermal temperature of adsorbents with high CO2 adsorption capacity cannot desorb CO2 efficiently in a real sunlight environment. Here, a novel solar energy-triggered regenerative bionic fiber adsorbent for CO2 capture was designed via bionic electrostatic and chemical cross-linking assembly of cellulose nanofibers, thermosensitive polymer poly(N-isopropylacrylamide), nano-graphene oxide and polyethyleneimine. Excellent photothermal transformation characteristics, thermosensitivity and high density of amino adsorption sites were synchronously endowed onto cellulose nanofibers with hydroxyl groups. The thermosensitivity and hydroxyl synergy of the adsorbent enables it an ultralow regeneration temperature (60 °C) by preventing the formation of refractory urea. Interestingly, the adsorbent possesses a high CO2 adsorption capacity (6.52 mmol/g) and can be efficiently regenerated by using renewable solar energy, indicating that it is a promising strategy for greatly reducing the energy consumption for adsorbent regeneration.