Effect of Electrolyte pH on the Inherent Electrochemistry of Layered Transition-Metal Dichalcogenides (MoS₂, MoSe₂, WS₂, WSe₂)

We set forth to investigate the changes in the inherent oxidative peaks of different transition-metal dichalcogenides (TMDs), namely MoS₂, MoSe₂, WS₂, and WSe₂, at different electrolyte pH values. Changing the pH of the electrolyte was found to influence and affect the inherent oxidation of TMDs, more noticeably the peak position. This could be attributed to the different reaction mechanisms and stability at the different pH values. An increase in the electrolyte pH from 0 to 8 shows a linear decrease in the peak potentials of the inherent oxidative peaks. However, small changes in peak potentials were observed at low alkaline pH levels (from 8 to 11). Beyond pH11, the emergence of an additional peak at low potentials, apart from the inherent oxidative peak, was observed for most of the TMD materials studied. This insight into the pH dependence of the oxidation of TMD materials is of paramount importance for their electrochemical applications. Reaching the peak: Changes in the inherent oxidative peaks of different transition metal dichalcogenides (TMDs), namely, MoS₂, MoSe₂, WS₂, WSe₂, at different electrolyte pH are investigated. The influence of pH can be attributed to the different reaction mechanisms and stability at the different pH values, which is of paramount importance for electrochemical applications of TMDs.