ABSTRACT
Aiming at solving the issue of wastewater purification, this work synthesized NH2-MIL-88B (Fe α In1-α ) photocatalysts by a simple one-pot method, which was employed for photocatalytic reduction of Cr(vi) and oxidation of TC-HCl. Compared with traditional NH2-MIL-88B (Fe) photocatalysts, NH2-MIL-88B (Fe0.6In0.4) displayed excellent photocatalytic performance; the photocatalytic redox rate for Cr(vi) and TC-HCl reached 86.83% and 72.05%, respectively. The good photocatalytic performance might be attributed to the metal-to-metal charge transition (MMCT) between Fe-O clusters and In-O clusters formed by doping In(iii) into NH2-MIL-88B (Fe), which provides effective active sites for the photocatalytic reduction and oxidation routes. Besides, the synergistic effect of the ligand-to-metal charge transition (LMCT) and MMCT expands the separation and transfer of photogenerated carriers and inhibits the recombination of electron-hole pairs, thus effectively improving the photocatalytic performance. Therefore, this work could provide a new method for the construction of mixed metal MOFs for the photocatalytic degradation of pollutants.
ABSTRACT
An Ag/AgCl/NH2-UiO-66 hybridized photocatalyst was successfully constructed via facile solvothermal with UV reduction method for efficient photocatalytic Cr (VI) reduction. The photoelectrochemical data indicate that compared with the UiO-66, the charge separation and transfer efficiency of Ag/AgCl/NH2-UiO-66 heterojunction is significantly enhanced due to the introduction of amine functionalization and formation of inorganic-organic hybrid. The surface plasmon resonance (SPR) effect deriving from Ag nanoparticles (NPs) largely extends photo-response range whilst the separation efficiency of photo-generated electrons and holes is improved significantly. The synthesized Ag/AgCl/NH2-UiO-66 hybrid system shows ameliorated structural stability and superior photocatalytic activity for Cr (VI) reduction under visible light irradiation, which is 1.7 times higher than that of the bare UiO-66. Furthermore, the possible mechanism of Cr (VI) reduction is proposed by analyzing electron transfer path in the ternary Ag/AgCl/NH2-UiO-66 hybridized system.
