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

The photocatalytic H production activity of polymer carbon nitride (g-CN) 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-CN. In the R-TAP-Pd(II)@g-CN 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 H production. The R-TAP-Pd(II)@g-CN presented a photocatalytic H generation rate of 1085 μmol g h when exposed to visible light, which was a about 278-fold increase compared with g-CN. This work finds a new approach to boost the photocatalytic efficiency of g-CN via supramolecular self-assembly.