Introducing phosphorus atoms into MoS2 nanosheets through a vapor-phase hydrothermal process for the hydrogen evolution reaction

Molybdenum disulfide (MoS₂)-based electrocatalysts have been considered as promising alternatives to platinum for use in the hydrogen evolution reaction (HER). Developing MoS₂ electrocatalysts with more active sites has been recognized as an efficient way to enhance the HER activity. Moreover, phase transition and heteroatom doping show great influence on the HER performance. In this work, we develop a vapor-phase hydrothermal (VPH) approach to introduce phosphorus (P) atoms into a MoS₂ nanosheet array on carbon fiber cloth, which presents enhanced HER activity compared with MoS₂ without P-doping. The improved performance is due to the synergistic effects of the new active sites formed by the P dopants and the sulfur (S) vacancies in the MoS₂ nanosheets generated by the doping of P atoms, which increases the number of active sites. In general, the obtained P-doped MoS₂/CFC exhibits a lower onset potential of 80 mV and an overpotential of 162 mV at 10 mA cm^-2 than MoS₂ without P-doping in 0.5 M H₂SO₄, accompanied by extremely large cathodic current density and excellent stability. This strategy may open up opportunities for heteroatom doping of electrocatalysts for various applications and provide a new method for material synthesis.