β-Mo2C nanoparticles/carbon nanotubes Mott-Schottky nanoarray on carbon cloth as freestanding cathodes for efficient hydrogen evolution reaction

s Developing efficient non-noble metal-based electrocatalysts for the hydrogen evolution reaction (HER) is urgently required for the large-scale electrolysis of water. Mo 2 C shows excellent HER catalytic activity. The construction of heterostructures by combining Mo 2 C and carbonaceous materials provides an effective strategy to modulate the electronic structure and hydrogen adsorption ability of molybdenum carbide . The β-Mo 2 C nanoparticles bundled on semiconducting carbon nanotubes (CNTs) with a Mott-Schottky heterojunction has been prepared in situ on the carbon cloth via a facile solvothermal and annealing process. Contributing to the synergistic effect of β-Mo 2 C and CNTs, the synthesized Mo 2 C/CNTs@CC electrode exhibits greatly enhanced HER catalytic activity with an overpotential of 123 mV to achieve a current density of −10 mA cm −2 , a Tafel slope of 51 mV dec −1 , and excellent durability. DFT calculations indicate that the CNTs donate electrons to β-Mo 2 C to enhance the coupling interfaces within β-Mo 2 C and CNTs and modify the electronic structure, resulting in a lower reaction barrier in the Volmer step and faster HER activities. This work provides a synthetic route to Mott-Schottky heterostructure Mo 2 C/CNTs with excellent HER catalytic activity.