Visible Light Induced Selective Aerobic Formation of N-benzylidene Benzylamine over 2-aminoterephthalic Acid Sensitized {110}-Facetted BiOCl Nanosheets

Surface modification with a photosensitizer is an efficient way to improve visible light activity of wide band gap semiconductors, but is rarely applied in photocatalytic organic synthesis. Herein, we report that 2-aminoterephthalic acid (ATA) sensitized {110}-facetted BiOCl nanosheets, prepared by a solvothermal method, exhibit outstanding photocatalytic activity for the selective oxidative coupling of benzylamine to N-benzylidenebenzylamine under visible light. UV-vis diffuse reflectance spectra confirmed that the introduction of ATA extends the light absorption of wide band gap BiOCl into the visible light region. Characterization by HRTEM and SAED indicated that the samples were predominantly terminated by {110} facets. BiOCl incorporating 0.18 % ATA exhibited superior activity for the photocatalytic oxidation of benzylamine under visible light, with 100 % conversion and 100 % selectivity towards N-benzylidenebenzylamine. The catalyst exhibited excellent recyclability and works well with other substituted benzylamines, suggesting its robust and universal nature. This work provides an example for the application of a low-cost and highly efficient visible-light-responsive photocatalyst in organic synthesis.