辐射冷却和太阳能加热驱动的 CO₂变温捕获

Temperature-swing adsorption is an effective technique for CO₂ capture, but the temperature swing procedure is energy-intensive, especially the heating and cooling processes. The low-energy-consumption temperature-swing system is realized by using polypyrrole-based nitrogen-doped porous carbon PPy-650 which combines passive radiative cooling and solar heating. During the adsorption process, the adsorbent layer is coated with a layer of hierarchically porous poly (vinylidene fluoride-co-hexafluoropropene) [P(VdF-HFP)_HP], which can cool the adsorbents to a sub-ambient temperature under sunlight through radiative cooling. For desorption, PPy-650 with excellent photothermal conversion ability is exposed to light irradiation for heating. The heating and cooling process is driven entirely by solar energy without any energy input. The regeneration of PPy-650 was investigated by means of adsorption-desorption cycles carried out at 700 W/m². The results demonstrate that PPy-650 has a good CO₂ working capacity (35.69 cm³/g) in this temperature-swing adsorption system, the adsorption capacity of PPy-650 did not decrease.