Interface Polarization State Reinforcement in CTF/Bi ₁₉ S ₂₇ Cl ₃ Boosting Photocatalytic Ammonia Synthesis

Designing differentiated charge distributed interface has been considered as effective strategy to boost photocatalysis. However, it is still difficult to realize the directional strong polarization to continuous drive directional charge transfer. Here, we present a polarization state reinforcement strategy by coupling Bi 19 S 27 Cl 3 with covalent triazine framework (CTF) atomic layers via strong bonding. The intrinsic Bi 1 ─S─Bi 2 polarize site pair in Bi 19 S 27 Cl 3 enables rapid bulk charge transport, while interfacial Bi─C/N bond further strengthens the Bi 1 ─S─Bi 2 polarization and favors fast interfacial electron transfer from Bi 19 S 27 Cl 3 to CTF. Then, the electron‐rich triazine N in CTF will serve as reactive sites to reduce the adsorbed NO 3 − to NH 4 + , with NH 4 + generation rate of 13.65 mmol g −1 h −1 in 320–780 nm, and apparent quantum yield up to 46.7% at 380 nm, 30.5% at 400 nm, which is superior to most reported photocatalyst. Moreover, the gradual shift from non‐covalent interactions of * NO over CTF to covalent interactions over CTF/Bi 19 S 27 Cl 3 can help to stabilize the intermediate and lower the rate‐limiting step energy barrier.