Amorphous Co–Mo–S ultrathin films with low-temperature sulfurization as high-performance electrocatalysts for the hydrogen evolution reaction

Making defects, structuring and incorporating transition-metal elements have all been demonstrated as effective strategies to enhance intrinsic activity toward the hydrogen evolution reaction (HER), but how to integrate all these merits into one system is still a challenge. An amorphous Co–Mo–S ultrathin film fabricated via low-temperature sulfurization, with rich defects, hierarchical structuring and transition metal doping, shows excellent HER performance and good working stability in acidic media. Therefore, the low-temperature sulfurizing method and hierarchical nanoarrays are extremely important to construct highly active and stable electrocatalytic gas-evolution electrodes.