▎ 摘　　要

Unique MoS2-SnS2 heterogeneous nanoplates have successfully in-situ grown on poly(3-(1-vinylimidazolium-3-yl)propane-1-sulfonate) functionalized polypyrrole/graphene oxide (PVIPS/PPy/GO). PVIPS can attract heptamolybdate ion (Mo7O246-) and Sn4+ as the precursors by the ion-exchange, resulting in the simultaneous growth of 1T'-MoS2 and the berndtite-2T-type hexagonal SnS2 by the interfacial induced effect of PVIPS. The obtained MoS2-SnS2/PVIPS/PPy/GO can serve as electrocatalysts, exhibiting good NRR performance by the synergistic effect. The semi-conducting SnS2 would limit the surface electron accessibility for suppressing HER process of 1T'-MoS2, while metallic 1T'-MoS2 might efficiently improve the NRR electroactivity of SnS2 by the creation of Mo-Sn-Sn trimer catalytic sites. Otherwise, the irreversible crystal phase transition has taken place during the NRR process. Partial 1T'-MoS2 and SnS2 have electrochemically reacted with N-2, and irreversibly converted into Mo2N and SnxNz due to the formation of Mo-N and Sn-N bonding, meanwhile, partial SnS2 has been irreversibly evolved into SnS due to the reduction by the power source in the electrochemical system. It would put forward a new design idea for optimizing the preparation method and electrocatalytic activity of transition metal dichalcogenides. (C) 2022, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.