Enhancing photocatalytic degradation efficiency via the construction of organic/inorganic S-scheme supramolecular hybrid heterostructures

This study demonstrates the successful construction of a hybrid van der Waals heterostructure (vdWH) consisting of 3D supramolecular networks and 2D semiconductor Ag3PO4, using hydrogen-bonded 3D networks H12SubPcBOPh2OH self-assembled onto Ag3PO4. The resulting organic/inorganic vdWH exhibits significantly enhanced photocatalytic degradation efficiency for oxytetracycline (OTC) and tetracycline (TC) under visible light irradiation, with apparent rate constants 1.8 and 1.5 times higher than those of pristine Ag3PO4, respectively. Moreover, after five photocatalytic cycles, the photocatalytic activity of vdWH was still much higher than that of pristine Ag3PO4. Molecular dynamics simulations indicate that the SubPc-3 supramolecular assembly is more prone to forming a 3D hydrogen bonding network rather than a 1D columnar stacking. In-situ irradiated X-ray photoelectron spectroscopy analyses and theoretical calculations confirm that the charge transfers between H12SubPcB-OPh2OH and Ag3PO4 are consistent with the S-scheme mechanism. This work provides a promising strategy for designing and fabricating efficient and stable supramolecular self-assembled semiconductor-based photocatalysts.