Rational inert-basal-plane activating design of ultrathin 1T' phase MoS2 with a MoO3 heterostructure for enhancing hydrogen evolution performances.

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.