Indoor CO2 capture-driven passive cooling for photovoltaics with ventilation energy reduction utilizing amine-functionalized adsorbents

In carbon capture, utilization, and storage processes, CO2 capture consumes 80 % of total energy consumption, reaching 3–8 MJ/kg which poses a formidable challenge. Conversely, buildings are responsible for approximately 40 % of final energy consumption and contribute over 30 % of CO2 emissions, highlighting the urgent need to reduce the building energy. In this work, a sustainable indoor CO2 capture-driven passive cooling system is developed for building-integrated photovoltaics with ventilation energy reduction by coating amine-impregnated mesoporous silica (PEI/MCM-41) to the rear of PV cells using supersonic cold spraying method. During nighttime, it effectively mitigates indoor CO2 concentration increase due to human respiration by capturing 1.64 mmol/g of CO2, enabling a reduction of 180 MJ/kg-thermal in winter and 30.4 MJ/kg-electric in summer within the building. In daylight hours, PV cells generate electricity, and the supplied radiant solar heat is consumed for CO2 desorption (latent cooling), lowering the average temperature of the PV cells and improving the power efficiency. PEI/MCM-41 achieves a remarkable cooling energy density of 242 J/g and average cooling power of 357 W/m2. It has been demonstrated that the present system can simultaneously reduce the building energy consumption and CO2 emission.