Ultrasmall palladium nanoparticles (1.5–2.5 nm) encapsulated within the highly porous and hydrothermally stable amine-functionalized metal–organic framework UiO-66 exhibit excellent catalytic activity for the selective conversion of vanillin to 2-methoxy-4-methylphenol.

In this article, we report the lowest-temperature CO oxidation catalyst supported on metal-organic frameworks (MOFs). We have developed a facile, general, and effective approach based on microwave irradiation for the incorporation of Pd nanoparticle catalyst within Ce-MOF. The resulting Pd/Ce-MOF material is a unique catalyst that is capable of CO oxidation at modest temperatures and also of efficient uptake of the product CO gas at low temperatures. The observed catalytic activity of this material toward CO oxidation is significantly higher than those of other reported metal nanoparticles supported on MOFs. The high activity of the Pd/Ce-MOF catalyst is due to the presence of Ce(III) and Ce(IV) ions within the metal-organic framework support. The Pd nanoparticles supported on the Ce-MOF store oxygen in the form of a thin palladium oxide layer at the particle-support interface, in addition to the oxygen stored on the Ce(III)/Ce(IV) centers. Oxygen from these reservoirs can be released during CO oxidation at 373 K. At lower temperatures (273 K), the Pd/Ce-MOF has a significant CO uptake of 3.5 mmol/g.

Water desalination and wastewater treatment via solar photothermal energy conversion are among the most important technologies to address the increasing pressing global water scarcity. Solar energy is the cleanest, most abundant, renewable natural resource available. Herein, we report the development of highly efficient, flexible, low weight, and cost effective Plasmonic Functionalized Cotton (PFC) nanocomposite materials for solar steam generation through the efficient evaporation of surface water pools. The PFC nanocomposites contain metallic nanoparticles that exhibit strong solar absorption followed by non-radiative relaxation causing the absorbed energy to be converted into heat for efficient water evaporation. The chemically modified cotton leads to a partial hydrophobic surface that allows the material to float on the water's surface and provide excellent thermal insulation properties in addition to facile and scalable synthesis. The PFC nanocomposites containing Au and Ag nanoparticles are demonstrated to be among the most efficient solar thermal converters reported to date for solar water desalination. The Au/Ag-PFC fibers exhibit average water evaporation rates of 1.4 and 11.3 kg m h with superb solar thermal efficiencies of up to 86.3% and 94.3% under 1 and 8 sun illumination, respectively. Furthermore, the Au/Ag-PFC fibers display stable evaporation rates over more than 10 repeated evaporation cycles without any performance decline under acidic solution at pH 2 or basic solution at pH 10. The successful application of the Au/Ag-PFC fibers for the removal of organic dyes from contaminated water through the solar steam generation is also demonstrated. The high solar thermal evaporation efficiency, excellent stability and long-time durability make the PFC nanocomposites excellent candidates for applications in seawater desalination and wastewater treatment by solar-steam generation.

In this work we report a new strategy to enhance the catalytic activity and selectivity in heterogeneous catalysis by using a hybrid support that consists of metal–organic framework (MOF) crystals and partially reduced graphene oxide (PRGO) nanosheets to disperse metal nanoparticle catalysts efficiently. We report the development of a Pd nanocatalyst incorporated within a 3 D hierarchical nanocomposite that consists of a Ce‐based MOF wrapped with thin PRGO nanosheets, Pd/PRGO/Ce‐MOF, as a heterogeneous tandem catalyst for the hydrodeoxygenation of vanillin, a common component in lignin‐derived bio‐oil, under mild reaction conditions. Our results demonstrate that the PRGO/Ce‐MOF hybrid scaffold is an excellent support for Pd nanoparticles for the transformation of vanillin into 2‐methoxy‐4‐methyl phenol, an important high‐value phenol compound that can be used directly in the chemical and pharmaceutical industries. The high catalytic performance of the Pd/PRGO/Ce‐MOF catalyst is attributed to the unique characteristics of the incorporation of the PRGO support that leads not only to a stable and uniform dispersion of the Pd nanoparticles but also to the presence of acidic active sites that promote the hydrogenolysis reaction.

In this study, the novel adsorbent UIO-66-IT was synthesized to extract mercury and phosphate ions from contaminated water. The synthetic strategy involved the preparation of the metal−organic framework (UIO-66-NH 2 ) followed by post-synthetic modification using the chelating ligand 2-imino-4-thiobiuret to form the UIO-66-IT adsorbent. The structure and the morphology of the adsorbent were investigated by a variety of analytical techniques including Fourier transform infrared, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunauer−Emmett−Teller surface area measurements. The adsorption of mercury and phosphate was optimized by studying the effect of pH, initial concentration, contact time, dose, temperature, and competitive ions. The results revealed exceptionally high adsorption capacities toward mercury and phosphate ions of 580 and 178 mg/g, respectively, at pH = 5.5 and an initial concentration of 1500 and 1000 mg/L. The adsorption isotherms are in excellent agreement with the Langmuir isotherm model, indicating the formation of a monolayer on the surface of UIO-66-IT. The kinetics of adsorption fit well with the pseudo-second-order kinetics model, which suggests the chemical adsorption of mercury ions via the nitrogen and sulfur functional groups of the adsorbent and the physical adsorption of phosphate anions by protonated functional groups on the surface of the UIO-66-IT adsorbent. Selectivity studies showed removal efficiencies of 98.9% Hg(II) from a solution containing a mixture of metal ions at 25 mg/L. Regeneration studies showed that the adsorbent can be recycled several times by using nitric acid for mercury removal and sodium chloride for phosphate removal. Removal efficiencies were higher than 99% for both regenerations. Due to the simple synthetic strategy via cost-effective starting materials, unique chemical structure, rapid adsorption kinetics, and high surface area, which lead to excellent removal efficiency, stability, and excellent regeneration, UIO-66-IT is introduced as a unique adsorbent for the selective removal of mercury and phosphate ions to remediate polluted water.