Ni-CoS2@MoS2 hollow nanorod array in-situ synthesized on Ti foil as Pt-free self-supporting electrode for efficient wide-pH hydrogen evolution

Green energy such as hydrogen energy has broad development prospects in promoting the adjustment of energy structure due to its advantages in cleanliness and efficiency. Hydrogen evolution reaction (HER) for water splitting can be used as a simple and effective avenue for hydrogen production. Platinum (Pt), a noble metal, has shown excellent catalytic performance as a conventional cathode catalyst for HER, but its high price has severely hindered its commercial application. Herein, a hollow nanorod array based Pt-free self-supporting electrode with a unique structure was developed for efficient hydrogen evolution reactions. This electrode was composed of a hollow ordered Ni-CoS2@MoS2 array as the main catalyst and a highly conductive Ti foil as a conducting substrate. In the synthesis process, ammonium tetrathiomolybdate was used as a multifunctional vulcanizing agent. Thanks to the unique structure of the hollow nanorods, the active ingredient was adequately revealed, making it possible to improve catalytic activity. This unique catalyst exhibited excellent HER performance at different pH values. Ni-CoS2@MoS2/Ti electrode exhibited high HER performance in alkaline, acidic, and neutral media, with overpotentials of 153, 192, and 196 mV at 10 mA cm–2 and Tafel slopes of 65.8, 67.8, and 93.3 mV dec–1, respectively.