Large-scale synthetic Mo@(2H-1T)-MoSe2 monolithic electrode for efficient hydrogen evolution in all pH scale ranges and seawater

Although molybdenum selenide with controllable phase and morphology is pivotal for high-efficiency hydrogen evolution reaction (HER), at present, the MoSe2-based HER electrodes widely applied to all pH scale ranges and seawater are remaining tremendous challenge, due to the absence of active sites, poor conductivity of MoSe2 and the limitation of synthetic method. In this work, the large-scale [email protected](2H-1T)-MoSe2 monolithic electrode was successfully fabricated by etching Mo mesh in Na2SeO3 solution via a hydrothermal technique. Continuous phase and morphology modulation of MoSe2 on Mo mesh and the optimal synthetic condition are described to fabricate a state-of-the-art electrode [email protected](2H-1T)-MoSe2 with the piezo-flexoelectric coupling effect and heterostructure. The HER tests of [email protected](2H-1T)-MoSe2 in all pH ranges and seawater exhibit an enhanced HER activity, high stability and cycle durability, which benefit from the synergistic interaction of the piezo-flexoelectric coupling effect of hybrid 2H-1T phase of MoSe2 nanosheets and heterojunction. Operando EIS and theoretical calculations also revealed this viewpoint. This strategy can also be extended arbitrarily to the large-scale preparation of other heterostructured monolithic electrodes for high-efficiency HER, such as [email protected]x (M = Ni, Cu, W, etc.). This study provides a simple, effective and low-cost approach to develop the state-of-the-art metal-based heterostructured electrodes for other energy-related applications.