Polarized Cu–Bi Site Pairs for Non‐Covalent to Covalent Interaction Tuning toward N2 Photoreduction

A universal atomic layer confined doping strategy is developed to prepare Bi24O31Br10 materials incorporating isolated Cu atoms. The local polarization can be created along the CuOBi atomic interface, which enables better electron delocalization for effective N2 activation. The optimized Cu‐Bi24O31Br10 atomic layers show 5.3× and 88.2× improved photocatalytic nitrogen fixation activity than Bi24O31Br10 atomic layer and bulk Bi24O31Br10, respectively, with the NH3 generation rate reaching 291.1 µmol g−1 h−1 in pure water. The polarized Cu–Bi site pairs can increase the non‐covalent interaction between the catalyst's surface and N2 molecules, then further weaken the covalent bond order in NN. As a result, the hydrogenation pathways can be altered from the associative distal pathway for Bi24O31Br10 to the alternating pathway for Cu‐Bi24O31Br10. This strategy provides an accessible pathway for designing polarized metal site pairs or tuning the non‐covalent interaction and covalent bond order. A universal atomic‐layer‐confined doping strategy is developed to prepare Bi24O31Br10 materials incorporating isolated Cu (Fe, Co, Ni) atoms. The polarized Cu–Bi site pairs favor better electron delocalization for effective N2 activation, and can work as reactive sites to tune the non‐covalent interactions of the intermediates, optimize the covalent bond order in NN, and alter the hydrogenation pathways.