Phase‐Restructured SnS ₂ Nanodots: Unlocking ORR Activity through Thermal Stress‐Mediated Fracturing

The production of electrocatalytically active materials from inert precursors through intricate engineering represents a frontier in sustainable energy research. The present study unveils a transformative thermal stress‐mediated fracturing strategy to activate the oxygen reduction reaction (ORR) in SnS 2, a material traditionally considered unsuitable for such electrocatalytic applications. By subjecting bulk SnS 2 hexagonal plates to extreme thermal shock via rapid heating followed by instant quenching in liquid nitrogen, a simultaneous reduction in dimensionality and a critical 1T‐to‐1H phase transition has been achieved, yielding ultra‐small 1H@1T‐SnS 2 nanodots (2–5 nm). High‐resolution aberration‐corrected STEM imaging reveals a restructured atomic lattice where the emergence of the 1H phase, coupled with plentiful edge sites, fundamentally reconfigures the electronic landscape. While the parent 1T‐SnS 2 follows an inefficient 2‐electron pathway, the phase‐restructured nanodots exhibit a robust 4‐electron oxygen reduction mechanism. Theoretical insights from Density Functional Theory (DFT) confirm that the synergy between the 1H‐phase transition and edge‐site enrichment lowers the Gibbs free energy for intermediate adsorption, effectively “unlocking” the catalytic potential of SnS 2 . This work provides an erudite blueprint for the phase‐and‐size engineering of non‐precious metal dichalcogenides, transmuting mundane semiconductors into high‐performance electrocatalysts for the next generation of fuel cells and metal‐air batteries.