Heterogeneous Nanostructure Based on 1T-Phase MoS₂ for Enhanced Electrocatalytic Hydrogen Evolution

As an electrocatalyst, conventional 2H-phase MoS₂ suffers from limited active sites and inherently low electroconductivity. Phase transitions from 2H to 1T have been proposed as an effective strategy for optimization of the catalytic activity. However, complicated chemical exfoliation is generally involved. Here, MoS₂ heterogeneous-phase nanosheets with a 1T phase (1T/2H-MoS₂) generated in situ were prepared through a facile hydrothermal method. The locally introduced 1T-phase MoS₂ can not only contribute more active sites but also markedly promote the electronic conductivity. Because of this unique structure, the as-synthesized 1T/2H-MoS₂ nanosheets exhibit remarkable performance for the hydrogen evolution reaction with a small overpotential of 220 mV at 10 mA/cm², a small Tafel slope of 61 mV/decade, and robust stability. This work facilitates the development of a two-dimensional heterogeneous nanostructure with enhanced applications.