Constructing 2D/2D g-C3N4/BiOCl Z-scheme heterojunction for synthesis of imines via photocatalytic coupling of benzylamine

Here, 2D/2D Z-scheme heterojunctions, BiOCl/g-C3N4 (CN-B), are successfully prepared for the photocatalytic coupling of benzylamine (BA) to N-benzylidenebenzylamine (NBA) in air atmosphere under visible light. The high conversion (96.1 %) of BA can be achieved over the optimal catalyst (CN-B-1.6), with a selectivity of NBA (95.2 %). The interface charges are redistributed on CN-B because of the strong interaction between BiOCl and gC3N4, benefiting to the activation of substrates. The results of In situ diffuse reflectance infrared Fouriertransform spectroscopy (in situ DRIFTS), Electron paramagnetic resonance (EPR) and X-ray photoelectron spectra (XPS) reveal that O2 and BA molecules can be activated via coordinating on the interface of CN-B, thus improving the photocatalytic performance. The migrated pathway of photogenerated carriers follows the mechanism of Z-scheme heterojunction, improving the utilization of electrons-holes. Finally, we put forward a possible mechanism at a molecular scale to explain the photocatalytic pathway. This work emphasizes how to create an effective heterojunction photocatalyst for the photocatalytic organic synthesis.