One-step turning leather wastes into heteroatom doped carbon aerogel for performance enhanced capacitive deionization

Exploring advanced electrode material is indispensable for achieving enhanced capacitive deionization (CDI) performance. Utilizing low-cost and eco-friendly leather wastes as precursors, herein a carbon aerogel with rich N, O and S doping has been constructed by a one-step activated pyrolysis process. Distortional carbon nanocrystallites (DCNs) in the material and its self hetero-doping could provide uneven surface charge distributions, thus improving both the electronic and ions conductivities, as well as water wettability of the electrode. Besides, the defects from its structure and doping could also act as active sites, boosting the adsorption capacity. In addition, the obtained aerogel exhibits a specific surface area of as high as 2523 m² g⁻¹ with abundant micropores, which is also favorable to salt ions storage. Therefore, CDI cell comprised of the carbon aerogel electrodes exhibits a maximum salt adsorption capacity (mSAC) of 20.92 mg g⁻¹ and a significantly higher average salt adsorption rate (ASAR) in comparison with commercial active carbon.