Nanoarchitectonic Ni-doped edge dislocation defect-rich MoS 2 boosting catalytic activity in electrochemical hydrogen production

The world is moving towards a more sustainable future, and hydrogen is emerging as a key player in this transition. Hydrogen production through the use of electrocatalysts is becoming increasingly popular as a sustainable and efficient method. Herein, we report the monodisperse nickel (Ni) nanoparticles incorporated molybdenum disulfide (MoS 2 ) (Ni/MoS 2 ) electrocatalyst synthesized via a hydrothermal method, followed by an annealing process. It is found that the edge dislocations which are topological defects that occur when a crystal lattice has an extra plane of atoms. These defects can drastically affect the chemical properties and electronic structure of materials, which can improve their electrocatalytic performance. However, defect-rich electrocatalysts for hydrogen evolution reaction (HER) is becoming more popular nowadays. It is not yet clear how the active sites of the edge dislocations of MoS 2 affect the catalytic properties of hydrogen evolution. The most promising electrocatalyst without precious metals is considered to be metallic MoS 2 (1T phase), which exhibits Pt-like HER performance in alkaline media. One of the expected functions of MoS 2 is to act as a conductive support with relatively large surface area for more catalytically active and highly dispersed Ni species. The 1T-MoS 2 exhibits remarkable catalytic properties for HER due to the abundance of active sites connected by edge dislocations. Compared with pristine MoS 2, the edge dislocation defect-rich Ni/MoS 2 shows the outstanding HER activity, delivering a current density of 10 mA cm −2 at an overpotential of only 89 mV with a lower Tafel slope of 59 mV dec −1. Additionally, chronopotential analysis is performed at a constant current density of 10 mA cm −2 for 30 h with minimal loss in overpotential, which demonstrates an extremely potential and stable HER catalyst.