Electron-photon harvesting via built-in electric field modulation in COF/MXene heterointerfaces

Photo-assisted flexible supercapacitors have emerged as transformative power solutions by integrating with solar photoirradiation-enhanced capacity (PIEC) to improve energy storage performance. However, the photogenerated carrier recombination and structural instability of existing metal oxides and carbon-based photoelectrodes hinder enhancement of PIEC performance in flexible supercapacitors for wearable electronics. Herein, we propose a dynamic bonding strategy to construct a core-shell covalent organic framework/MXene heterostructure (COF-316-Ti 3 C 2 T x ) with engineered heterointerfaces for flexible photo-enhanced micro-supercapacitors (FPMSCs). This method facilitates the oriented growth of covalent organic framework-316 (COF-316) on a Ti 3 C 2 T x nanosheet to form a core-shell heterostructure by anchoring monomers. Theoretical calculations and experiments reveal that the built-in electric field modulation accelerates photogenerated electron transfer and suppresses charge recombination (carrier lifetime is doubled). The core-shell heterostructure endows the realization of FPMSCs with enhanced mechano-electrochemical stability, including 180° bending stability and 97.5% of capacitance retention after 10,000 cycles.