Search

[Display omitted] A subtle flower-like MIL-125-NH 2 @BiOI was fabricated by a facile solvothermal method for simultaneously eliminating Cr(VI)/tetracycline mixed pollutants under visible light. The strong interaction between amino in MIL-125-NH 2 and Bi3+ of BiOI promotes the formation of this unique inlaid structure and enables the favorable contact between MIL-125-NH 2 and BiOI, thus accelerating the transfer of charge carriers. Remarkably, MIL-125-NH 2 @BiOI displays a superior activity compared with that of two monomers for the photocatalytic reduction of Cr(VI) and degradation of tetracycline. More significantly, the photocatalytic efficiency can be further boosted in the coexistence of Cr(VI) and tetracycline, which is 1.8 and 1.6 times that of single Cr(VI) and tetracycline, respectively. The synergistic effect between Cr(VI) reduction and tetracycline oxidative degradation can further facilitate the separation of photo-induced electrons and holes, resulting in the improved efficiencies in the Cr(VI)/tetracycline coexistent environment. This work sheds light on that MOF-based photocatalysts possess huge potential for practical environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] Pancake-like TiO 2 (M-TiO 2) derived from the metal-organic framework was inlaid into three-dimensional flower-like BiOI through a facile solvothermal method. M-TiO 2 supplies large surface area and mesoporous structure for attachment and transfer of the substrates and products, while BiOI acts as a photosensitizer to absorb visible light and generates electrons and holes. The distinct structure of M-TiO 2 /BiOI gives a favorable contact between the two monomers, and promotes the transfer of charge carriers. In conjunction with the proper band positions of M-TiO 2 and BiOI, the efficient separation of electron-hole pairs is attained. Benefiting from the above cooperative effects of M-TiO 2 and BiOI, the performance for the vanillin generation from sodium lignosulfonate (SLS) over M-TiO 2 /BiOI composites has a prominent improvement under visible light. Specifically, the yield over optimal M-TiO 2 /BiOI sample is about 5.8 mg/g SLS , obviously superior to that over pristine M-TiO 2 (~1 mg/g SLS) and BiOI (~1.1 mg/g SLS). It is found that h+ and O 2 – play the key role for vanillin generation from sodium lignosulfonate, and the low vanillin generation under UV–vis light sheds light on that OH is an adverse factor. We hoped that this work could inspire the studies on the photocatalytic valorization of biomass using noble metal-free catalysts. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Noble metal nanoparticles (NPs) functionalized MOFs are attractive materials for photocatalytic reactions, and outstanding catalytic performances can be expected, especially when they have intrinsically matched crystal faces between metals and MOFs. This study discovered that the photocatalytic oxidation of aromatic alcohols to aldehydes was enhanced over Au/UiO-66-NH 2 or Au/UiO-66 but suppressed over Pt loaded counterparts, whereas the reduction of Cr(VI) was boosted over both two catalysts. In reactions, the conversion of benzyl alcohol was 17.1% over UiO-66-NH 2 and 7.6% over UiO-66, and an enhanced conversion was obtained over Au/UiO-66-NH 2 (30.5%) and Au/UiO-66 (24.1%). However, the conversion was decreased over Pt/UiO-66-NH 2 (9.3%) and Pt/UiO-66 (<1%). Experimental results revealed strong correlations between Zr-MOFs and loaded metal NPs, as Zr centers promoted the formation of Pt(200) planes that suppressed the production of ·O 2 − intermediates to oxidize aromatic alcohols, whereas Pt(200) exhibited no effect on the Cr(VI) reduction triggered by photo-induced electrons. The findings in this study on constructing noble metal NPs functionalized Zr-MOFs catalysts with specially-matched crystal structures and on distinguishing photocatalytic mechanisms on oxidation of alcohols and reduction of Cr(VI) would provide valuable information for designer (photo)catalysts based on MOFs and their applications in such as catalysis and environmental remediation. [ABSTRACT FROM AUTHOR]