<i>In situ</i> X-ray photoelectron spectroscopy using a conventional Al-Kα source and an environmental cell for liquid samples and solid-liquid interfaces

Abstract

X-ray photoelectron spectroscopy (XPS), which intrinsically requires vacuum, was used to characterize chemical species in a liquid using laboratory XPS apparatus equipped with a conventional Al-Kα source and an environmental cell with an ultra-thin silicon nitride membrane as a quasi-transparent window for the transmission of X-rays and photoelectrons. Aqueous solutions of cesium chloride at different concentrations were encapsulated in the cells, and the membrane in contact with the solution was irradiated with X-rays to collect the photoelectrons emitted from the chemical species in a liquid through the membrane. Cs 4d photoelectron peaks were observed, and the peak intensity increased proportionally with the concentration. Thus, the quantitative analysis of solution species by this method is demonstrated.