Synthesis of High Surface Area, Carbyne‐Derived, Acidic Nanocarbons Obtained from Municipal Wastes for Daily Sorption Thermal Battery Cycle

Modern materials that allow for an easy way to store energy are the top of the top of recent investigations. Near room temperature synthesis of high-area carbyne-derived nanocarbons from municipal wastes. The acidic and consequently hydrophilic nature of the surface of the studied nanocarbons is confirmed by various analytical techniques. It has been shown that low-temperature dehydration in a concentrated sulfuric acid environment does not result in the incorporation of sulfonic groups, and the total concentration of surface acid groups is close to 3 nm². This value, combined with the Raman spectra characteristic of the carbyne structures, allows the conclusion that acidic derivatives of the carbynes have been obtained. A high concentration of surface functional groups causes the results from low-temperature N₂ isotherm are underestimated (≈100 m² g^-1). The correct surface area values are possible to be obtained from measurement in the aqueous phase using methylene blue as a model molecule (≈1400 m² g^-1). High acidity prevents the adsorbate condensation, typical for carbon materials during water adsorption. By mitigating the S-shape of the adsorption isotherm, the amount of adsorbed and desorbed water is temperature-dependent, allowing to obtain ≈1200 kJ kg^-1 at a typical daily thermal cycle.