1D/2D Heterostructures as Ultrathin Catalysts for Hydrogen Evolution Reaction

2D MoS2 has emerged as a promising alternative to Pt‐based catalysts for hydrogen evolution reaction (HER) due to its low cost and earth abundance. However, insufficient active sites of basal plane and poor conductivity become the foremost factors restricting the catalytic performance of MoS2. Here, a facile strategy is presented to enhance the HER performance of MoS2 by converting its 2D structure into 1D/2D heterostructures of Mo6Te6/MoS2(1−x)Te2x by the in situ tellurization. As‐prepared 1D/2D heterostructures exhibit excellent HER performance with the Tafel slope of ≈56 mV dec−1 (only one‐third of that for pristine MoS2). The enhanced HER catalytic activity is attributed to more Te/S vacancies introduced by tellurization, which serve as the active sites as suggested by theoretical calculations. Besides, the formation of highly conductive well‐aligned quasi‐1D Mo6Te6 nanobelts facilitate charge transport in HER. Previous work provides a facile approach to construct mixed dimensional materials, and opens up a new avenue to the properties modulation of 2D transition metal chalcogenides. 1D/2D heterostructures of Mo6Te6/MoS2(1−x)Te2x are prepared by in situ tellurization of MoS2. Attributing to Te/S vacancies in MoS2(1−x)Te2x planes and faster charge transport of Mo6Te6 nanobelts, as‐prepared heterostructures dramatically enhance hydrogen evolution reaction performance of pristine MoS2. The work reveals a facile approach to construct mixed dimensional materials, and provides a new avenue to optimize the properties of transition metal chalcogenides.