Application of chemically synthesized polypyrrole with hydro-sponge characteristic as electrode in water desalination

In this article, the chemical oxidative approach was employed to synthesize bulk sponge-like polypyrrole; p-toluenesulfonate (pTSNa), sodium benzene-sulfonate (BSNa) and sodium nitrate (NaNO₃) were chosen, respectively, as doping agents to modify the sponge polypyrrole. The microstructure, specific surface area and electrochemical activity of doped polypyrrole samples were characterized. Through repeated expansion and contraction tests, it was proved that the bulk polypyrrole samples exhibited excellent sponge property. To investigate the potential desalination ability, this type of sponge-characteristic polypyrrole was processed into electrodes, and applied in saline solution to remove sodium ions by the electrochemical approach. The results showed that the sponge polypyrrole performed wonderful desalination effect with above 20 mg Na⁺ for per gram polypyrrole.