Characterization of Etched Graphite Nanoplates and Their Nonwoven Electrode Applications

Carbon materials are under the investigative spotlight for their earth-abundance, sustainability, and intriguing electronic properties. Amongst all nano-carbon allotropes, exfoliated graphite nanoplates (xGnP) currently dominate the commercial market due to their low cost and high performance. However, smooth basal planes of xGnP possess limited surface functionality, leading to poor thin film-forming ability and poor adhesion of xGnP with flexible textile substrates. To overcome these issues, here we have proposed a facile acid etching process for localized oxidation of xGnP sheets. The etching process removes some xGnP surface, hence forming pits on xGnP sheets, along with introducing surface functional groups. The functional surface of etched-xGnP facilitates uniform coating on polyester microfiber nonwoven membrane, resulting in a flexible nonwoven structured electrode. The comparison of etched and pristine xGnP electrodes revealed better conductivity, dye adsorption, electrocatalytic activity, and heat generation ability of the etched-xGnP. The higher surface area and oxygen/nitrogen doping incurred during the etching process were observed to play a critical role in the superior performance of etched-xGnP. The facile etching process will advance the understanding and applications of flexible electrodes for wearable electronic devices.