Enhanced Catalytic Denitrification Performance of Ruthenium-based Catalysts by Hydrogen Spillover from a Palladium Promoter.

Catalytic denitrification, a promising technology for nitrate removal, is increasingly limited by the rising price of Pd. Replacing Pd with less-expensive Ru would significantly reduce the cost; however, Ru-based catalysts have been reported to perform inconsistently in denitrification applications, making their replacement prospects unclear. Herein, the surface oxidation of Ru catalysts was confirmed to be a key factor that inhibits activity.

Enhanced Fenton-like catalytic activity and stability of g-CN nanosheet-wrapped copper phosphide with strong anti-interference ability: Kinetics and mechanistic study.

Metal-based Fenton-like catalysts usually activate HO to produce free radicals (OH and O) for the degradation of organic pollutants. However, a catalytic reaction dominated by free radicals is easily interfered with by various inorganic anions and water matrices. Herein, g-CN-wrapped copper phosphide (CuP), as a highly efficient Fenton-like catalyst, was successfully synthesized by a simple low-temperature phosphidation method.

Mesoporous silica-protected silver nanoparticle disinfectant with controlled Ag ion release, efficient magnetic separation, and effective antibacterial activity.

Ag is the most effective metal disinfectant against pathogenic microorganisms and thus, various approaches have been exploited to enhance the dispersity and control the release of Ag ions from Ag nanoparticles. In this study, a superparamagnetic FeO@SiO@Ag@porous SiO disinfectant with a double-layer core-shell structure was developed. Its superparamagnetic FeO nanosphere core ensured its good dispersity in water and allowed its easy magnetic separation after treatment.

Creation of Pd/AlO Catalyst by a Spray Process for Fixed Bed Reactors and Its Effective Removal of Aqueous Bromate.

Palladium nanoparticles were grown on sub-millimeter activated AlO particle support by spraying HPdCl solution evenly onto the support, followed with a thermal reduction under H atmosphere. Compared with its counterpart created by the conventional impregnation method, the Pd/AlO catalyst created by the spray process could enrich the existence of active Pd nanoparticles on the surface of the catalyst support and increase their degree of dispersion, resulting in a much higher activity in the catalytic reduction of bromate in water. The effect of AlO support particle size on the bromate removal rate was also investigated, which demonstrated that smaller support particle size could have higher activity in the catalytic reduction of bromate in water because of its larger exposed surface.

Post-illumination activity of SnO2 nanoparticle-decorated Cu2O nanocubes by H2O2 production in dark from photocatalytic "memory".

Most photocatalysts only function under illumination, while many potential applications require continuous activities in dark. Thus, novel photocatalysts should be developed, which could store part of their photoactivity in "memory" under illumination and then be active from this "memory" after the illumination is turned off for an extended period of time. Here a novel composite photocatalyst of SnO2 nanoparticle-decorated Cu2O nanocubes is developed.

Synthesis of Superparamagnetic Core-Shell Structure Supported Pd Nanocatalysts for Catalytic Nitrite Reduction with Enhanced Activity, No Detection of Undesirable Product of Ammonium, and Easy Magnetic Separation Capability.

Superparamagnetic nanocatalysts could minimize both the external and internal mass transport limitations and neutralize OH(-) produced in the reaction more effectively to enhance the catalytic nitrite reduction efficiency with the depressed product selectivity to undesirable ammonium, while possess an easy magnetic separation capability. However, commonly used qusi-monodispersed superparamagnetic Fe3O4 nanosphere is not suitable as catalyst support for nitrite reduction because it could reduce the catalytic reaction efficiency and the product selectivity to N2, and the iron leakage could bring secondary contamination to the treated water. In this study, protective shells of SiO2, polymethylacrylic acid, and carbon were introduced to synthesize Fe3O4@SiO2/Pd, Fe3O4@PMAA/Pd, and Fe3O4@C/Pd catalysts for catalytic nitrite reduction.

Synthesis of Mn₃O₄/CeO₂ Hybrid Nanotubes and Their Spontaneous Formation of a Paper-like, Free-Standing Membrane for the Removal of Arsenite from Water.

One-dimensional nanomaterials may organize into macrostructures to have hierarchically porous structures, which could not only be easily adopted into various water treatment apparatus to solve the separation issue of nanomaterials from water but also take full advantage of their nanosize effect for enhanced water treatment performance. In this work, a novel template-based process was developed to create Mn3O4/CeO2 hybrid nanotubes, in which a redox reaction happened between the OMS-2 nanowire template and Ce(NO3)3 to create hybrid nanotubes without the template removal process. Both the Ce/Mn ratio and the precipitation agent were found to be critical in the formation of Mn3O4/CeO2 hybrid nanotubes.

Synthesis of tin oxide nanospheres under ambient conditions and their strong adsorption of As(III) from water.

The development of highly efficient As(iii) adsorbents is critical to largely simplify the arsenic treatment process and lower its cost. For the first time, SnO2 nanospheres were demonstrated to possess a highly efficient As(iii) adsorption capability from water in a near neutral pH environment as predicted by the material criterion we recently developed for the selection of highly efficient arsenic adsorbents. These SnO2 nanospheres were synthesized by a simple and cost-effective hydrolysis process with the assistance of ethyl acetate under ambient conditions, which had a good dispersity, a narrow size distribution, a relatively large specific surface area, and a porous structure.

Creation of Cu2O@TiO2 composite photocatalysts with p-n heterojunctions formed on exposed Cu2O facets, their energy band alignment study, and their enhanced photocatalytic activity under illumination with visible light.

The creation of photocatalysts with controlled facets has become an important approach to enhance their activity. However, how the formation of heterojunctions on exposed facets could affect their photocatalytic performance ranking had not yet been investigated. In this study, Cu2O@TiO2 core-shell structures were created, and Cu2O/TiO2 p-n heterojunctions were formed on various exposed facets of Cu2O cubes, Cu2O cuboctahedra, and Cu2O octahedra, respectively.

Multifunctional properties of cyanate ester composites with SiO2 coated Fe3O4 fillers.

SiO2 coated Fe3O4 submicrometer spherical particles (a conducting core/insulating shell configuration) are fabricated using a hydrothermal method and are loaded at 10 and 20 vol % into a bisphenol E cyanate ester matrix for synthesis of multifunctional composites. The dielectric constant of the resulting composites is found to be enhanced over a wide frequency and temperature range while the low dielectric loss tangent of the neat cyanate ester polymer is largely preserved up to 160 °C due to the insulating SiO2 coating on individual conductive Fe3O4 submicrometer spheres. These composites also demonstrate high dielectric breakdown strengths at room temperature.