Metal nanoparticles decorated MIL-125-NH2 and MIL-125 for efficient photocatalysis

Metal nanoparticles (NPs) decorated MOFs for photocatalysis has drawn enormous attention in the past decade. Here, a series of M/Ti-MOFs (M = Pt and Au, Ti-MOFs = MIL-125-NH2 and MIL-125) has been synthesized through a facile post-synthetic method and the metal NPs highly dispersed on surface of MOFs with major sizes of 3-9 nm. Light absorption edges of scaffolds are crucial in the photocatalytic oxidation of benzyl alcohol over M/MIL-125-NH2 and M/MIL-125. The conversion of benzyl alcohol over Pt/MIL-125-NH2 is 2.4 times and 1.9 times higher than that of pristine MIL-125-NH2 and Au/MIL-125-NH2, respectively. Besides, Pt/MIL-125-NH2 photocatalyst also exhibited good activity for Cr(VI) reduction compared to that of MIL-125-NH2. The enhanced photocatalytic activity of Pt/MIL-125-NH2 is contributed to the rapid transfer of photo-induced electrons and decreased recombination of electron-hole pairs, which is verified by measurements of photocurrent and Electrochemical Impedance Spectroscopy. We hope that this study will provide worthy information for designing metal/MOFs or metal/MOFs-NH2 photocatalysts.