Bimetal-organic layer-derived ultrathin lateral heterojunction with continuous semi-coherent interfaces for boosting photocatalytic CO2 reduction

Current heterojunction photocatalysts suffer from sluggish charge transfer due to the discontinuous interfaces at an atomic level. Herein, we report a NiO–Co3O4 ultrathin lateral heterojunction using NiCo-based bimetal–organic layers as precursors. The atomic-resolution images display a unique continuous semi-coherent interface between NiO and Co3O4. The experimental results confirm that the continuous semi-coherent interfaces effectively expedite the electron transfer from NiO to Co3O4. Concomitantly, the electron transfer raises d-band center of Co3O4 in NiO–Co3O4 toward Fermi level, as revealed by the density functional theory calculations. As a result, the *COOH intermediate can be strongly bound on cobalt reactive centers. The successful modulation of charge transfer and intermediate binding by continuous semi-coherent interfaces leads to a remarkable gas yield of 22.67 mmol h−1 from photocatalytic CO2 reduction over NiO–Co3O4. This work highlights the crucial roles of interface engineering in regulating carrier kinetics and surface reactions.