Polarized Cu-Bi Site Pairs for Non-Covalent to Covalent Interaction Tuning toward N 2 Photoreduction.

A universal atomic layer confined doping strategy is developed to prepare Bi 24 O 31 Br 10 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 N 2 activation. The optimized Cu-Bi 24 O 31 Br 10 atomic layers show 5.3× and 88.2× improved photocatalytic nitrogen fixation activity than Bi 24 O 31 Br 10 atomic layer and bulk Bi 24 O 31 Br 10 , respectively, with the NH 3 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 N 2 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 Bi 24 O 31 Br 10 to the alternating pathway for Cu-Bi 24 O 31 Br 10 . This strategy provides an accessible pathway for designing polarized metal site pairs or tuning the non-covalent interaction and covalent bond order.