Sustainable process for functional group introduction onto HOPG by exposing [rad]OH and 1O2 using a radical vapor reactor (RVR) without any chemical reagents

Abstract

Efficient generation of reactive oxygen species (high concentrations of 1O2 and OH) was successfully performed using a radical vapor reactor (RVR) at ordinary temperature and atmospheric pressure without using any chemical reagent. In this study, we successfully introduced modified functional groups onto highly oriented pyrolytic graphite (HOPG) by a sustainable process using an RVR. Although the introduction of a functional group onto HOPG is difficult because of the presence of strong CC bonds in HOPG, the RVR can easily modify it because reactive oxygen species have high energy and high reactivity. Moreover, the RVR process does not require any chemical reagent; it also does not produce any exhaust, except for air and water. The RVR-treated HOPG was analyzed by contact angle measurement (CAM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), and scanning tunneling microscopy (STM). These analyses revealed that the HOPG surface became hydrophilic and it showed different physical property owing to the modification caused by the introduced oxygen element.