Prolonged exposure of graphite oxide to soft X-ray irradiation during XPS measurements leads to alterations of the chemical composition

X-ray photoelectron spectroscopy is an indispensable technique to analyse the structural and chemical features of graphene-based materials. Such detailed characterization is often imperative prior to the usage of these materials for various applications. In this work, the effects of the continuous irradiation with soft X-rays during the analysis of graphite oxide with X-ray photoelectron spectroscopy were investigated. Prolonged exposure to the X-ray source was observed to cause an overall decrease in the amount of oxygen-containing groups, which could consequently lead to the wrong interpretation of the XPS analysis result. Proper and careful consideration on the time span of XPS analysis of graphite oxide is, thus, highly advocated.