Synergy of Platinum Single Atoms and Platinum Atomic Clusters on Sulfur-Doped Titanium Nitride Nanotubes for Enhanced Hydrogen Evolution Reaction

Highly dispersed Pt, such as Pt single atoms and atomic clusters, has great potential in the electrocatalytic hydrogen evolution reaction (HER) due to the high atomic efficiency and unique electronic configuration. Rationally regrating the electronic structure of Pt catalysts is desirable for promoting the HER performance. Herein, a 3D self-supported monolithic electrode consisting of Pt single atoms (Pt-SAs) and Pt atomic clusters (Pt-ACs) anchored on sulfur-doped titanium nitride nanotubes (S-TiN NTs) encapsulated in polyaniline (PANI) on Ti mesh (PANI@Pt/S-TiN NTs/Ti) via a facile electrochemical strategy for efficient HER is designed and synthesized. Contributed by the unique structure and composition and the synergy of Pt-SAs, Pt-ACs and S-TiN NTs, the PANI@Pt/S-TiN NTs/Ti electrode exhibits ultrahigh HER activities with only 12, 25 and 39 mV overpotentials at -10 mA cm(-2) in acidic, alkaline and neutral media, respectively, and can maintain a stable performance for 25 h. Impressively, the mass activities are respectively up to 26.1, 22.4, and 17.7 times as that of Pt/C/CC electrode. Theoretical calculation results show that the synergistic effect of Pt-SAs, Pt-ACs, and S-TiN NTs can optimize the electronic structure of Pt and generate multiple active sites with a thermodynamically favorable hydrogen adsorption free energy (Delta G(H*)), thereby resulting in an enhanced HER activity.

Automated summary

A highly efficient 3D self-supported electrode consisting of Pt single atoms and atomic clusters anchored on sulfur-doped titanium nitride nanotubes has been designed and synthesized. This electrode exhibits remarkable electrocatalytic activity for the hydrogen evolution reaction in different media, and maintains stability over a long period of time. Theoretical calculations indicate that the optimized electronic structure and multiple active sites of the Pt single atoms and atomic clusters contribute to the enhanced activity.