Photocatalytic energy driven building sustainable power, air purification and air dehumidification

Solar photocatalytic oxidation (PCO) is an advanced air purification technology, but most of the heat generated during the PCO process is not effectively utilized, leading to low photocatalytic efficiency. Expanding the light spectrum and multi-effect utilization of thermal energy are effective methods to improve solar energy efficiency. While indoor humidity control contributes to building energy consumption. Therefore, we developed a novel visible-light driven photocatalyst (C-TiO2) and proposed a multifunctional system integrating photocatalysis, thermoelectric generation (TEG), and metal-organic frameworks (MOF) (PC-TEG-MOF). Experimental tests on the purification, power, and dehumidification performance of the hybrid PC-TEG-MOF device under different solar radiations, and outdoor full-day experiments were conducted. Thermal, electrical, catalysis, and dehumidification coupled models were developed to analyze application performance across Chinese cities. Main results were: (1) The C-TiO2 exhibited 96.4 % solar absorptivity in the visible spectrum and 96 % emissivity in the atmospheric window, with a maximum single-pass ratio of 85.1 %. (2) Under solar radiation of 1000 W/m2, the maximum power density was 462 mW/m2, with an 80.8 % single-pass ratio and a clean air volume of 279 m3/(h·m2). (3) Full-day tests show that the hybrid device generated a power density of 578.5 mW/m2 during daytime, achieving a single-pass ratio of 80.6 %, and a power output of 86.8 mW/m2 at night, while lowering the relative humidity by 8.5 %. (4) The multifunctional roof-integrated PC-TEG-MOF device showed annual power densities from 31.6 kW/m2 to 88.9 kW/m2, with air-conditioning energy savings from 0.38 kW/m2 to 20.5 kW/m2 across Chinese cities.