A systematic study on the changes in properties of an activated carbon cloth upon polarization

The effects of polarization on properties of activated carbon cloth (ACC) have been investigated systematically. The polarization-treated ACC samples were prepared by polarizing them in Na2SO4 or KH2PO4/KOH buffer solutions at potentials from −1.5 to 5.0 V. The properties, such as surface area, pore size distribution (PSD), total pore volume, amount and nature of the surface functional groups and surface acidity, of pristine and polarization-treated ACC samples were determined. The samples were also characterized electrochemically by determining the properties such as specific capacitance and potential at point of zero charge (EPZC). Anodic polarization in different electrolytes was found to cause oxidation on ACC. Although the surface textural properties did not change considerably, the changes took place in chemical and electrochemical properties upon anodic polarization were found to be important. The increase in surface acidity shifted the pHPZC from 7.40 to 3.21 and EPZC from 164 to 355 mV. The optimum potential range, considered to be safe for polarization of ACC, was determined as −1.5 to +0.8 V.