Energy-Yielding Mini Heat Thermocells with WS₂ Water-Splitting Dual System to Recycle Wasted Heat

In response to global energy shortage and global warming, liquid-type energy-yielding thermocells regulated by temperature differences are developed in this study, enabling generation of electric power from excess thermal energy or waste heat. The cells comprise nature pigments and wastewater. The cells are stable and functional within a narrow range of temperature difference, which can be as small as 40 °C. Under 40 °C temperature difference and with the solar cell size of 1 cm², daily energy generated by the designed solar cell can reach as high as 10022.4 KJ/m² in just 1 day, which is the highest energy-generation rate reported so far for the same type solar cells. The WS₂ nanosheet is utilized in liquid-type energy-yielding thermocells for assembly as water-splitting cells. When the pigments of Mona Lavender plectranthus are loaded into the electrolyte under a 40 °C temperature difference, the water-splitting cells demonstrated an energy conversion efficiency as high as 53.98% ± 4% for hydrogen evolution processing. Therefore, the dual fuction of the mini heat recycling system, e.g., power generation and hydrogen generation, has been achieved. Thus, the solar cells developed here have promising applications in recycling industrial waste heat and waste hot water.