Beneficial effect of Re doping on the electrochemical HER activity of MoS2 fullerenes

Abstract

Electrochemical generation of hydrogen by non-precious metal electrocatalysts at a lower overpotential is a focus area of research directed towards sustainable energy. The exorbitant costs associated with Pt-based catalysts is the major bottleneck associated with commercial-scale hydrogen generation. Strategies for the synthesis of cost-effective and stable catalysts are thus key for a prospective ‘hydrogen economy’. In this report, we highlight a novel and general strategy to enhance the electrochemical activity of molybdenum disulfide (MoS₂) in a fullerene structure (IF-). In particular, pristine (undoped) and rhenium-doped nanoparticles of MoS₂ with fullerene-like structures (IF-MoS₂) were studied, and their performance as catalysts for the hydrogen evolution reaction (HER) was compared to that of 2H-MoS₂ particles (platelets). The current density of the IF-MoS₂ was higher by one order of magnitude than that of few-layer (FL-) MoS₂, due to the enhanced density of the edge sites. Furthermore, Re doping of as low as 100 ppm in IF-MoS₂ decreased the onset potential by 60–80 mV and increased the activity by 60 times compared with that of the FL-MoS₂. The combined synergistic effect of Re doping and the IF structure not only changes the intrinsic nature of the MoS₂ but also increases its reactivity. This strategy highlights the potential use of the IF structure and Re doping in electrocatalytic hydrogen evolution using MoS₂-based catalysts.