Rational inert-basal-plane activating design of ultrathin 1T′ phase MoS2 with a MoO3 heterostructure for enhancing hydrogen evolution performances

Abstract

Activating both the inert basal plane and edge sites of molybdenum-disulphide (MoS₂) is a significant yet challenging step in boosting their performance for the hydrogen evolution reaction (HER). In this study, the density functional theory calculation results show that the incorporation of MoO₃ fragments leads to a slight out-of-plane distortion of the 1T-MoS₂ phase of the resultant O–Mo–S framework, giving rise to a 1T′-MoS₂/MoO₃ heterostructure, where gap states around the Fermi level allow hydrogen evolution over both its basal plane (Mo-site) and edges (S-sites). Under the guidance of density functional theory, conducted via an efficient one-step solvothermal route, ultrathin metallic-phase 1T′-MoS₂/MoO₃ heterojunction nanosheets with 3D hollow structures and a very small size (d = ∼120 nm) were precisely designed and constructed. The electrochemical measurements show that such a material possesses a low overpotential at 10 mA cm⁻² (η₁₀, 109 mV) and a Tafel slope (42 mV dec⁻¹). In addition, the HMHSs also led to excellent H₂ production up to 22.108 mmol g⁻¹ h⁻¹ and good durability under the photocatalytic process. To the best of our knowledge, the performance of this catalyst is better than that of most previously reported Mo-based non-noble catalysts for the HER. The excellent HER activity of this catalyst is highlighted by its unique synergistic effect between 1T′-MoS₂ and MoO₃ with an activated inert basal plane and fantastic hollow structure with a large surface area and high content of edge sites.