Pd(II) coordination molecule modified g-C₃N₄ for boosting photocatalytic hydrogen production

The photocatalytic H₂ production activity of polymer carbon nitride (g-C₃N₄) is limited by the rapid recombination of photoelectron-hole pairs and slow surface reduction dynamic process. Here, a supramolecular complex (named R-TAP-Pd(II)) was fabricated via self-assembly of (R)-N-(1-phenylethyl)-4-(4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)benzamide (R-TAP) with Pd(II) and used to modify g-C₃N₄. In the R-TAP-Pd(II)@g-C₃N₄ composite photocatalyst, the spin polarization of R-TAP-Pd(II) can promote charge transfer and inhibit photogenerated carrier recombination, as confirmed by spectral tests and photoelectrochemical performance tests. Electrochemical tests and in situ X-ray photoelectron spectroscopy (XPS) tests proved that the Pd(II) ion in the R-TAP-Pd(II) molecule can serve as active sites to accelerate H₂ production. The R-TAP-Pd(II)@g-C₃N₄ presented a photocatalytic H₂ generation rate of 1085 μmol g^-1 h^-1 when exposed to visible light, which was a about 278-fold increase compared with g-C₃N₄. This work finds a new approach to boost the photocatalytic efficiency of g-C₃N₄ via supramolecular self-assembly.