Recently, nanjing university of aeronautics and astronautics wan-lin guo academician team used ethanol solvent evaporation of the research on carbon nanotube generating effect, and found that the ethanol in the carbon nanotube surface evaporation, can produce continuous grade v voltage, the voltage is only produced in capillary liquid film front millimeter half wet area, and potential evaporation caused by flow almost negligible. The study was published in Joule, a leading energy journal, on March 1, 2022, entitled "Evaporating Potential."

Evaporation is a process in which molecules transform from liquid to gas and absorb heat spontaneously from the environment. It is a new negative heat emission power generation method that converts low quality heat energy into electric energy by evaporation. The phenomenon of evaporative power generation has been widely verified in a variety of nanostructured materials, but the underlying mechanism is not clear, often ascribed to the traditional flow potential, which is the potential generated by ionic flow when a solution flows through a slit under a pressure gradient. Since evaporation always induces liquid flow within the nanostructured material, it is difficult to discern effects beyond the flow potential.

Wanlin Guo and his team at Nanjing University of Aeronautics and Astronautics first discovered that evaporation can produce volt-level voltage and significant current without significant flow potential. Further experiments and first-principles calculations show that the evaporation potential is derived from the evaporation of polar ethanol molecules from the carbon nanomaterial at the three-phase interface to escape directly driven charge motion within the material. In addition to ethanol, other polar solvents can produce similar potentials. This potential, generated directly by the evaporation of polar molecules on the surface of the material, is called the evaporation potential. The discovery of evaporation potential provides a new idea for the development of water volt energy technology using natural evaporation for energy conversion.

Compared with other power generation methods, evaporative power generation takes advantage of evaporation, which is common in nature, and converts the heat energy in the environment into useful electric energy without additional mechanical work input. It is a new green energy way with negative heat emission. The discovery of evaporation potential is conducive to further improving the power density of evaporation devices, and laying evaporation devices in large areas of ocean, lake and other waters for power generation, which provides a new idea and way to alleviate the energy crisis and achieve carbon neutrality.

Link: https://www.sciencedirect.com/science/article/abs/pii/S254243512200068X?via%3Dihub