A Multifunctional Photothermal Catalyst Enabling Full-Day Sustainable Power and Indoor Air Quality Control

Solar photothermal catalytic (PTC) purification holds great potential for indoor air pollution control, but efficiently collecting energy at the catalytic interface to maximize solar energy utilization and meet building requirements remains a global challenge. This study develops a novel infrared-light-driven photothermal catalyst, Mn₇Co₃Ce₁O_x, which efficiently utilizes solar and ambient energy, offering three functions: catalysis, heating, and cooling. Furthermore, this study proposes an innovative hybrid system that integrates PTC film, thermoelectric generator (TEG), and metal–organic frameworks (MOFs). Through synergetic effects, the system combines the heating-catalysis-cooling effect of the PTC film with the moisture-induced adsorption/desorption heat of the MOFs, achieving year-round power generation, dehumidification, and air purification. Results show that Mn₇Co₃Ce₁O_x has a full-spectrum solar absorptivity of 94.3% and an atmospheric window emissivity of 95.7%. Under infrared light, the pollutant removal rate on the photothermal catalytic interface reaches 90.9%. Within 4 h, the thermoelectric power density increased by 640.1%, the relative humidity decreased by 16.8%, and the clean air volume reached 270.8 m³·h⁻¹·m⁻². When the system is applied to building rooftops in 34 provincial capital cities in China, the simulation results show annual power density of 30–105.3 kW·m⁻², air conditioning energy savings of 11.2–353.5 kW·m⁻², and clean air volume of 296.3–1119.3 m³·h⁻¹·m⁻².