Iridium-Triggered Phase Transition of MoS2 Nanosheets Boosts Overall Water Splitting in Alkaline Media

Metallic phase molybdenum disulfide (1T-MoS2), with its fast carrier mobility and highly abundant active sites, plays a vital role in the field of catalysis. However, the development of a simple and efficient strategy for the preparation of stabilized 1T-MoS2 remains a great challenge. Herein, we report the spontaneous phase transformation of MoS2 from the 2H to the 1T phase, caused by the strong metal-support interaction during iridium (Ir) adsorption. The resulting Ir/MoS2 heterostructures show higher catalytic activity for overall water splitting than those of commercial Pt/C and IrO2 in alkaline media. We believe that the spontaneous phase transformation of this material not only opens up a new perspective for developing advanced catalysts for alkaline water splitting but also presents an efficient and intriguing method for the phase engineering of two-dimensional materials.