Preparation of raspberry-like γ-Fe2O3/crackled nitrogen-doped carbon capsules and their application as supports to improve catalytic activity

Green approach for the fabrication of a ternary nanocatalyst (Ag-ZnONPs@Cy) for visible light-induced photocatalytic reduction of nitroarenes to aminoarenes

In recent times, the incorporation of metal oxide nanoparticles with organic dyes has piqued the interest of numerous researchers due to their diverse applications under visible light instead of UV radiation. This investigation employed a three-step methodology to fabricate cyanidin-sensitized silver-doped zinc oxide nanoparticles (Ag-ZnO@Cy). Initially, cyanidin dye was extracted from fresh black mulberry fruit, followed by the eco-friendly synthesis of Ag-ZnO nanoparticles (Ag-ZnONPs). The successful integration of the prepared cyanidin dye with Ag-ZnONPs was achieved through a straightforward, environmentally benign, and cost-efficient procedure. The resultant ternary composite underwent comprehensive characterization and confirmation utilizing various techniques, such as SEM, FT-IR, EDX, DRS, elemental mapping, and XRD. The experimental results for Ag-ZnONPs@Cy demonstrated that the nanocrystalline wurtzite exhibited spherical shapes with an average crystal size of 27.42 nm. Moreover, the photocatalytic activity of the synthesized Ag-ZnONPs@Cy was meticulously investigated under blue LED light irradiation. This inquiry encompassed examinations of catalyst amount, regeneration, stability, reusability, and the influence of light source on the hydrogenation of nitroarenes to the corresponding aminoarenes. The findings shed light on the potential of this composite for diverse photocatalytic applications.

Production of copper nanoparticles exhibiting various morphologies via pulsed laser ablation in different solvents and their catalytic activity for reduction of toxic nitroaromatic compounds

Comparative experiments were conducted to determine the effects of various solvents (i.e., deionized water, methanol, ethanol, 1-propanol, butanol, ethylene glycol, hexane, and acetonitrile) on the final compositions, morphologies, and catalytic activities of copper-based nanoparticles (NPs). The NPs were effectively synthesized by pulsed laser ablation (PLA) using a copper plate as the target. The obtained copper NPs were characterized utilizing various analytical techniques. It was established that the developed methodology allows for the production of NPs with different morphologies and compositions in a safe and simple manner. When laser ablation of a solid copper plate was performed in acetonitrile, the formation of copper(I) cyanide cubes was observed. On the other hand, in deionized water and methanol, spherical and rod-like particles of copper(I) and copper(II) oxide were detected, respectively. The catalytic activity of the prepared copper NPs in the reduction of aromatic nitro compounds, such as 4-nitrophenol and nitrobenzene, was also evaluated. A high k value was determined for the reduction over the copper(II) oxide NPs produced in methanol. Moreover, particles with graphitic carbon (GC) layers exhibited superior catalytic performance in the reduction of a hydrophobic substance, i.e., nitrobenzene, over the reduction of 4-nitrophenol. The enhanced catalytic activity of this catalyst may be due its unique surface morphology and the synergistic effects between the copper nanostructure and the GC layer. Lastly, a detailed reduction pathway mechanism for the catalytic reduction of 4-nitrophenol and nitrobenzene has been proposed.

Synthesis of ultrathin metal oxide and hydroxide nanosheets using formamide in water at room temperature

Here, 6 different ultrathin (<5 nm) 2D metal oxides and hydroxides have been successfully synthesized via a simple precipitation route in formamide aqueous solution at room temperature.

Highly effective catalytic reduction of nitrobenzene compounds with gold nanoparticle-immobilized hydroxyapatite nanowire-sintered porous ceramic beads

A catalytic ceramic bead with micron-sized and interconnected porous channels, adjustable porosity, high catalytic activity, and long-term stability is prepared.

A γ-Fe2O3-modified nanoflower-MnO2/attapulgite catalyst for low temperature SCR of NOx with NH3

A novel mesoporous γ-Fe₂O₃-modified nanoflower-MnO₂/attapulgite catalyst has been fabricated through a facile hydrothermal method and used for low temperature SCR of NO_x with NH₃.

Preparation of Magnetically Recyclable Yolk/Shell Fex Oy /PdPt@CeO2 Nanoreactors with Enhanced Catalytic Activity

Noble metal nanoparticles (NPs) have recently received considerable attention from researchers working in the field of catalysis. However, the development of new methods allowing these materials to reach their maximum catalytic properties remains challenging. Nanoreactors could lead to dramatic improvements in activity with the help of the intrinsic confinement effect. In this study, we designed a series of yolk/shell Fe_x O_y /PdPt@CeO₂ composites, where the Fe_x O_y NPs acted as a movable core, allowing for the uniform distribution of the PdPt alloys on the inner surface of the CeO₂ shell. The high porosity and existence of hollow voids in the CeO₂ shell allowed these Fe_x O_y /PdPt@CeO₂ composites to be used as nanoreactors in catalytic reactions. As well this confinement effect, we identified two structural features that led to enhanced catalytic activity, including (i) the replacement of monometallic NPs with a bimetallic PdPt alloy and (ii) the replacement of a chemically inert support with a reactive CeO₂ shell. The resulting nanoassembled catalysts displayed higher activities toward the catalytic reduction of dyes than the reference samples. Moreover, these catalysts were readily recovered and reused because of the magnetic Fe_x O_y core.

Facile fabrication of γ-Fe2O3-nanoparticle modified N-doped porous carbon materials for the efficient hydrogenation of nitroaromatic compounds

Novel γ-Fe₂O₃-nanoparticle modified N-doped porous carbon materials were facilely prepared and used for efficient catalytic hydrogenation of nitroaromatic compounds.

Superparamagnetic nanoparticles as a recyclable catalyst: a new access to phenol esters via cross dehydrogenative coupling reactions

CuFe₂O₄ superparamagnetic nanoparticles were utilized as a recyclable heterogeneous catalyst for the direct synthesis of chemical structures containing both phenol ester and benzothiazole moieties via cross dehydrogenative coupling reactions.