Inverse Design of Anthraquinone-Mimicking COFs via Electronic Fingerprints for Sacrificial-Agent-Free Photocatalytic...

Photocatalytic H₂O₂ production from H₂O and O₂ provides a sustainable alternative to the energy-intensive, multistep anthraquinone (AQ) process that relies on metal catalysts (e.g., Pd/Ni). Although many photocatalysts have been explored, achieving high efficiency under sacrificial-agent-free conditions with a rationally defined active site remains challenging. Here, we report an inverse-design strategy for covalent organic frameworks (COFs) based on "boat-like C═N-conjugated fragments" (-C═N-C═N- or -N═C-C═N-) which mimic key AQ reactivity by integrating active molecular fragments into periodic frameworks through a bottom-up approach. First-principles calculations identified 39 molecular fragments, including 36 newly proposed structures, and demonstrated their ability to drive the two-electron oxygen reduction reaction via sequential protonation and electron transfer. Unlike conventional single-property descriptors (e.g., band gap), we introduce a holistic electronic activity descriptor based on density-of-states (DOS) similarity to screen 106 designed COFs. This electronic fingerprint identified 11 candidates with >70% total DOS and >60% carbon partial DOS similarity relative to a high-performance reference. Subsequent Gibbs free-energy analyses predict that 9 candidates can support sacrificial-agent-free H₂O₂ production under visible light, corresponding to a theoretical screening success rate of approximately 81%. Experimental validation included the synthesis of TRI-BIP-TRI (TBiT) via trifluoromethanesulfonic acid-catalyzed cyclotrimerization. Under visible light (>400 nm) in pure water under O₂, TBiT produces H₂O₂ at 3084.27 μmol g^-1 h^-1 without sacrificial agents. These results establish a computation-guided framework for designing COF photocatalysts for sustainable H₂O₂ production.