posted on 2024-02-22, 16:08authored byI-Wen Peter Chen, Yi-Lun Tseng, Jeremiah Hao Ran Huang, Kuan-Lun Chen, Tsai Yun Liu, Jui-Chin Lee
Enhancing electrocatalytic performance relies on effective
phase
control, which influences key catalytic properties, such as chemical
stability and electrical conductivity. Traditional methods for manipulating
the phase of transition-metal dichalcogenides (TMDs), including high-temperature
synthesis, Li intercalation, and doping, involve harsh conditions
and energy-intensive processes. This study introduces an innovative
approach to crafting heterophase structures (2H-1T-WS2)
in TMDs, using WS2 as a model compound, encompassing both
semiconducting (2H) and metallic (1T) types through a straightforward
potential activation method. Insights from in situ electrochemical
Raman spectroscopy, HR-TEM, and XPS measurements reveal distinctive
partial phase-transition behavior. This behavior enables the partially
exposed basal plane of 2H-1T-WS2 to demonstrate superior
activity in the hydrogen evolution reaction (HER), attributed to enhanced
electrical conductivity and the exposure of highly active sites. The
potential-induced phase transition presents promising avenues for
the development of catalysts with heterophase structures.