Simultaneous excitation of PdCl₂ hybrid mesoporous g-C₃N₄ molecular/solid-state photocatalysts for enhancing the visible-light-induced oxidative removal of nitrogen oxides

A simple and efficient molecular/solid-state hybrid photocatalyst consisting of noble metal (i.e., Auᴵᴵᴵ, Ptᴵᵛ, and Pdᴵᴵ) chlorides-functionalized-mesoporous graphitic carbon nitride (mpg-CN) was developed to improve the photocatalytic performance of mpg-CN toward NO removal. Compared with the parent mpg-CN, the optimal 1% PdCl₂ modified mpg-CN increased the conversion efficiency by approximately 33%, improved the inhibiting efficiency of NO₂ release by approximately three times, and promoted the long term stability of photocatalysts for NO removal in a continuous flow model reaction system. The prepared samples were characterized by X-ray diffraction, transmission electron microscopy with energy-dispersive X-ray spectroscopy elemental mapping, ultraviolet–visible light absorbance spectroscopy, X-ray photoelectron spectroscopy, photoluminescence emission spectroscopy and electron paramagnetic resonance spectroscopy. The ultrafast charge separation and efficient generation of O₂•⁻ oxygen species were achieved by the charge transfer model of PdCl₂/mpg-CN similar to the solid-state Z-scheme system. This charge transfer model contributed to the high photocatalytic performance of the prepared PdCl₂/mpg-CN molecular/solid-state hybrid photocatalyst. Copyright © 2015 Elsevier B.V.