A study of the effect of sonication time on the catalytic performance of layered WS from various sources.

WS is a transition metal dichalcogenide (TMD) with many potential applications from catalysis to sensing, and is of interest both in its bulk and monolayer forms. There is discrepancy in the literature on the reported electrocatalytic effect of layered WS. In this study, we examine two issues: the influence of the WS source and the effect of a common agitation technique via ultrasonication on the observed electrocatalysis. Bulk WS from five different chemical providers demonstrated different HER electrocatalytic performances. Changes to the duration of sonication result in different HER electrocatalytic performances across all WS materials. This may affect the efficiency of subsequent modifications from which these TMD materials serve as precursor materials. On the other hand, while WS materials from different suppliers showed varying HET performances, changes in sonication time have no significant effect on their HET performances. Both the WS source and the duration of sonication have different implications for the electrochemical performance of bulk WS and thus represent important variables to consider in research involving WS.