Reverse Thinking of the Aggregation‐Induced Emission Principle: Amplifying Molecular Motions to Boost Photothermal Efficiency of Nanofibers**

Abstract Using reverse thinking of the aggregation‐induced emission (AIE) principle, we demonstrate an ingenious and universal protocol for amplifying molecular motions to boost photothermal efficiency of fibers. Core–shell nanofibers having the olive oil solution of AIE‐active molecules as the core surrounded by PVDF‐HFP shell were constructed by coaxial electrospinning. The molecularly dissolved state of AIE‐active molecules allows them to freely rotate and/or vibrate in nanofibers upon photoexcitation and thus significantly elevates the proportion of non‐radiative energy dissipation, affording impressive heat‐generating efficiency. Photothermal evaluation shows that the core–shell nanofibers with excellent durability can reach up to 22.36 % of photothermal conversion efficiency, which is 26‐fold as the non‐core–shell counterpart. Such a core–shell fiber can be used for photothermal textiles and solar steam generation induced by natural sunlight with green and carbon‐zero emission.