Breaking of π‐Continuity by σ‐Linkers in Covalent Organic Frameworks for Efficient Photoreduction and Recovery of Gold From Electronic Waste

Photoreduction of metal ions plays a central role in the recovery of precious metals from electronic waste, yet its design is still largely governed by a semiconductor paradigm that links extended π‐conjugation and long‐range charge transport to superior performance. Herein, we challenge this assumption by demonstrating that deliberate disruption of π‐continuity via σ‐linkers in covalent organic frameworks (COFs) affords a more effective electronic architecture for localized redox reactions. The resulting π‐disrupted framework (σ‐COF) generates low‐energy, spatially confined electronic states that prolong photogenerated electron lifetimes and promote their transfer to adsorbed Au(III) species. Under illumination, σ‐COF exhibits a dramatic enhancement in gold uptake from electronic‐waste‐derived solutions, increasing from ∼1000 to 3045 mg/g, whereas a structurally analogous π‐conjugated framework (π‐COF) shows only a modest increase (from ∼1200 to 1700 mg/g). Spectroscopic and photoelectrochemical studies reveal efficient electron accumulation at redox‐active sites without reliance on extended π‐delocalization, with adsorption and reduction occurring within the same local domains. This work establishes controlled π‐disruption as a new electronic design principle for COF photoreductants in noble metal recovery.