Comparison of supercapacitive behaviors of polyaniline doped with two low-molecular-weight organic acids: D-tartaric acid and citric acid

Polyaniline (PANI) is chemically synthesized using two low-molecular-weight organic acids (D-tartaric acid and citric acid) as the dopants, respectively. The doped PANI is characterized by field emission scanning electron microscopy, FT-IR spectra, and X-ray diffraction. The two doped PANIs exhibit different electrochemical properties, especially in the supercapacitive behaviors. Compared with citric acid-doped PANI, D-tartaric acid-doped PANI shows higher specific capacitance (525 F/g at 1 A/g) and cyclic stability. The good electrochemical behaviors of D-tartaric acid-doped PANI might be attributed to the two carboxyl groups of D-tartaric acid, which are beneficial to the oriented growth of PANI chains. The results demonstrate that compared with citric acid, D-tartaric acid is a promising dopant for PANI used in supercapacitors.