Construction of novel Pd/CeO2/g-C3N4 nanocomposites as efficient visible-light photocatalysts for hexavalent chromium detoxification

Abstract

In this study, we report a series of novel palladium nanoparticles (Pd) supported cerium oxide (CeO2)/graphitic carbon nitride (g-C3N4) nanocomposites, fabricated via the simple strategy, which were used for the detoxification of toxic hexavalent chromium to benign trivalent chromium under visible light irradiation. The synthesized Pd/CeO2/g-C3N4 nanocomposites were characterized by various tools including powder X-ray diffraction (PXRD), fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (DRS/UV–vis), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectra (EDS). The wrapping with surface of graphitic carbon nitride nanosheets can efficiently promote the interface charge separation and transmission over the ternary photocatalyst, which was studied by photoluminescence spectra (PL) analysis and electrochemical impedance spectroscopy (EIS) spectra. The obtained 3% Pd/CeO2/g-C3N4 nanocomposite photocatalyst exhibit an excellent photocatalytic performance when compared to other single and composite counter parts. The 3% Pd/CeO2/g-C3N4 exhibits a strong synergistic effect which arises due to the interactions between palladium nanoparticles, CeO2 and graphitic carbon nitride resulting in the lower recombination of photo-induced charge carriers with enhanced photocatalytic activity. This work implies that the synergistic Pd/CeO2/g-C3N4 nanocomposites would be a new kind of high-efficiency visible-light-driven photocatalysts materials for the detoxification of public safety and security.