Effect of hydrofluoric acid modification on electrochemical properties of prolifera-based activated carbon

Abstract

In order to improve the electrochemical performance of the activated carbon electrode material, the activated carbon was treated with acid washing and modified by hydrofluoric acid solution, and the pore structure characteristics of the activated carbon were improved by dissolving the silica salt in the hydrofluoric acid solution by dissolving the silica salt in the hydrofluoric acid solution. At the same time, the surface functional groups containing Si—O bonds and Si—H bonds with strong hydrophobicity on the surface of activated carbon were removed, so that the activated carbon electrode material has a larger specific surface area and stronger wettability, thereby making the capacitor produce larger the electric double layer capacitance. The experimental results show that the acid washing modification treatment of activated carbon with HF solution, the silica salts in the activated carbon are basically removed, the connectivity of pore channels was enhanced, the number of pore structures was increased, and the specific surface area of the activated carbon electrode material reached 2983 m2/g. Compared with the activated carbon without acid washing modification, the specific surface area of the activated carbon after acid washing modification is increased by 31.23%, which improves the surface functional groups of the activated carbon. When the current density was 0.1 A/g, the specific capacitance of the capacitor is as high as 338 F/g, even at current density of 10 A/g, the capacitor still maintains a high specific capacitance of 302 F/g and exhibits good cycling stability.

Keywords

• activated carbon
• hydrofluoric acid
• dissolution
• modification
• electrochemistry