Recently, the reliable supply of clean fresh water is becoming increasingly difficult as global and regional development accelerates, and this has become a bottleneck issue for the sustainable development of many countries. Chestnut-like carbon were prepared PCNFs grown on activated carbons using the catalytic gasification with Fe - Ni catalysts in air. Catalytic gasification of activated carbon was carried out at 400℃ for 1 h at each temperature. The PCNFs grown on activated carbon at 600℃ using activated carbon gasified with a 0.1% Ni-Fe catalyst at 450℃. The surface area of Chestnut-like carbons were 2401 m2/g. Additional specific capacitances of Chestnut-like carbon are significantly higher than those of other activated carbons. Chestnut-like carbon electrodes show approximately 44% retention of the specific capacitance, which is higher than that of the virginity activated carbon. Thus, Chestnut-like carbon electrode can be predicted to yield better performance in the capacitive deionization (CDI) process.