ABSTRACT Carbon cloth is widely chosen as the substrate for electrical catalysts. However, its practical use is limited by its relatively low specific surface area and hydrophobicity, which hinder the deposition of active components and overall catalytic performance. In this study, nitric acid pretreatment was used to oxidize the carbon cloth, modify its surface morphology, enhance surface functionalization, and increase its charge‐transfer capacity. After pretreatment, the surface area is significantly improved through etching and roughening, and hydrophilic and conductive groups are introduced and coordinated on the surface, facilitating the ion adsorption and charge transfer. These modifications enhance the electrochemical performance of the carbon cloth by increasing the electrochemical surface area (ECSA), lowering the energy barrier for the oxygen evolution reaction (OER), and reducing impedance, making it a better substrate for the OER catalyst. All these enhancements strongly support hydrothermal deposition and growth of active components, resulting in more uniform surface coverage and the formation of a 3D hierarchical structure. Additionally, by comparing the characterization and measurement results of carbon cloth pretreated at different nitric acid concentrations, the optimal nitric acid concentration for pretreating carbon cloth has been determined.
JIANG et al. (Sun,) studied this question.