Design of ruthenium-doped MoS2 microsphere with optimal electronic structure for enhanced hydrogen evolution

Abstract Engineering the electronic structure is significant to design of high active electrocatalysts, while it is challenging to create an optimal configuration and understand the enhanced mechanism. Here, we reported the design of molybdenum disulfide (MoS2) with an optimal electronic structure via introducing ruthenium (Ru) and sulfur vacancy to boost electrochemical hydrogen evolution. Specially, the uniform and monodispersed MoS2 microspheres with an average diameter of 567 nm were prepared through a microemulsion technology. The sulfur vacancies in MoS2 and 2Ru-MoS2 were demonstrated by EPS. The optimized 2Ru-MoS2 delivered a much lower overpotential of 70 mV (10 mA cm−2), compared with MoS2, 1Ru-MoS2, and 3Ru-MoS2. The parabolic enhancement mechanism related to the reduced band gap, the appropriate electron density, and the lowered barrier was revealed by density functional theory calculations. Our work shed light to rational design of highly efficient electrocatalysts via efficiently utilization of metal doping and vacancy.