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.