Surface Sensitive Studies of Interfacial Water Structure in Saturated Aqueous Solution of NaClO4

Abstract

Over the past years, it has been found that understanding the metal/water interaction plays a vital role in multidisciplinary fields ranging from heterogeneous catalysis and electrocatalysis to water in salt systems for advancing commercial battery technologies. It is also believed that the main properties of the WiS (water in salt) electrolytes are mainly linked to the chemical and physical properties of the interfaces between the water molecules in the WiS system and the metal electrode. This research focuses on conducting surface-sensitive studies on interfacial water in WiS systems, and the main approach of these experiments is to investigate water interaction and orientation as a function of the surface charge and NaClO4 concentration at the water/Gold electrode interface. In pursuit of this objective, ATR (attenuated total reflectance) was utilized to gain knowledge about the structure of water molecules in the solution as the concentration of NaClO4 increasing Additionally, ATR technique can provide an insight into the hydrogen bonding in the water in salt system. Utilizing ATR-SEIRAS (Attenuated Total Reflectance Surface-Enhanced Infrared Absorption Spectroscopy) in the subsequent phase of the project could potentially demonstrate valuable data about potential-dependent water adsorption as well as changes in hydrogen network strength in the double layer region as a function of the applied potential. The outcomes from the ATRSEIRAS technique provided a representation of the possible orientation of water molecules in different potentials. The hydrogen-oriented upward arrangement for water molecules is proposed in positive potentials, while in negative potentials, the hydrogen atoms of water are closer to the surface. Subsequently, the hydrogen network is stronger on the positively charged surface