Photothermal–Thermoelectric Synergistic Enhancement of PEDOT/CNT/PPy Flexible Textile Thermoelectric Devices for Waste Heat and Solar Energy Harvesting

Wearable thermoelectric generators (TEGs) rely on significant thermal gradients. They are susceptible to ambient conditions, including temperature and humidity, which compromise their longevity, wearability, and breathability, thereby limiting their utility in human microenvironments. This study introduced a layer-by-layer assembled photothermoelectric fabric comprising poly(3,4-ethylenedioxythiophene)/carbon nanotubes/polypyrrole (PEDOT/CNT/PPy), engineered for self-powered electricity generation through the capture and conversion of environmental solar and thermal energy. Poly(3,4-ethylenedioxythiophene) was deposited on the fabric via low-temperature interfacial polymerization, incorporating carbon nanotubes to establish an organic/inorganic hybrid system, thereby enhancing the composite material’s overall thermoelectric performance. Subsequently, to enhance the thermal-to-electric conversion of the PEDOT/CNT thermoelectric fabric, it was integrated with polypyrrole, which exhibited superior photothermal conversion properties, constructing an organic/inorganic photothermoelectric fabric with a core–shell architecture to achieve an integrated light-to-heat, heat-to-electricity composite conversion. The PEDOT/CNT/PPy flexible photothermoelectric fabric achieved a maximum output voltage of 612.52 μV under infrared light irradiation and an output voltage of 270 μV under a temperature differential of 20 °C. Furthermore, a thermoelectric device assembled from three PEDOT/CNT/PPy strip fabrics affixed to the human arm generated an output voltage of 300 μV at room temperature. Consequently, the developed flexible photothermoelectric conversion fabric demonstrates potential for significant applications in innovative wearable technology and the sustainable energy sector.