Highly efficient ozone elimination by metal doped ultra-fine Cu2O nanoparticles

Nowadays, ozone contamination becomes dominant in air and thus challenges the research and development of cost-effective catalyst. In this study, metal doped Cu2O catalysts are synthesized via reduction of Cu2+ by ascorbic acid in base solutions containing doping metal ions. The results show that compared with pure Cu2O, the Mg2+ and Fe2+ dopants enhance the O3 removal efficiency while Ni2+ depresses the activity. In specific, Mg-Cu2O shows high O3 removal efficiency of 88.4% in harsh environment of 600,000 mL/(g·hr) space velocity and 1500 ppmV O3, which is one of the highest in the literature. Photoluminescence and electron paramagnetic spectroscopy characterization shows higher concentration of crystal defects induced by the Mg2+ dopants, favoring the O3 degradation. The in-situ diffuse reflectance Fourier transform infrared spectroscopy shows the intermediate species in the O3 degradation process change from O22- dominant of pure Cu2O to O2- dominant of Mg-Cu2O, which would contribute to the high activity. All these results show the promising prospect of the Mg-Cu2O for highly efficiency O3 removal.

CuO Nanoparticles and Microaggregates: An Experimental and Computational Study of Structure and Electronic Properties

The link between morphology and properties is well-established in the nanoparticle literature. In this report, we show that different approaches in the synthesis of copper oxide can lead to nanoparticles (NPs) of different size and morphology. The structure and properties of the synthesized NPs are investigated with powder X-ray diffraction, scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS). Through detailed SEM analyses, we were able to correlate the synthetic pathways with the particles' shape and aggregation, pointing out that bare hydrothermal pathways yield mainly spheroidal dandelion-like aggregates, whereas, if surfactants are added, the growth of the nanostructures along a preferential direction is promoted. The effect of the morphology on the electronic properties was evaluated through DRS, which allowed us to obtain the electron bandgap in every system synthesized, and to find that the rearrangement of threaded particles into more compact structures leads to a reduction in the energy difference. The latter result was compared with Density Functional Theory (DFT) computational models of small centrosymmetric CuO clusters, cut from the tenorite crystal structure. The computed UV-Vis absorption spectra obtained from the clusters are in good agreement with experimental findings.

Chemical conversion based on the crystal facet effect of transition metal oxides and construction methods for sharp-faced nanocrystals

In-depth research has found that the nanocrystal facet of transition metal oxides (TMOs) greatly affects their heterogeneous catalytic performance, as well as the property of photocatalysis, gas sensing, electrochemical reaction, etc. that are all involved in chemical conversion processes. Therefore, the facet-dependent properties of TMO nanocrystals have been fully and carefully studied by combining systematic experiments and theoretical calculations, and mechanisms of chemical reactions are accurately explained at the molecular level, which will be closer to the essence of reactions. Evidently, as an accurate investigation on crystal facets, well-defined TMO nanocrystals are the basis and premise for obtaining relevant credible results, and shape-controlled synthesis of TMO nanocrystals thereby has received great attention and development. The success in understanding of facet-dependent properties and shape-controlled synthesis of TMO nanocrystals is highly valuable for the control of reaction and the design of high-efficiency TMO nanocrystal catalysts as well as other functional materials in practical applications.

Facile synthesis of homogeneous hollow microsphere Cu-Mn based catalysts for catalytic oxidation of toluene

There emerges an urgent stipulation towards the enhanced toluene catalytic combustion nanocatalysts for whittling down the footprint of toluene, a notorious air pollutant. Unfortunately, Few materials which are currently made accessible both present the high catalytic performance lower than 250 °C and keep durable at elevated temperatures. Herein, we demonstrate an expeditious salt hydrolysis-driven redox-precipitation protocol wherein H⁺ donated by the hydrolysis of copper salt was used to initiate the regioselective reduction of KMnO₄ by H₂O₂ under controlled redox kinetics in order to assemble the homogeneous mixed solid solution hollow microsphere Cu-Mn-based structure. Manifold characterization technologies unveil that in this unique nanbomicrosphere the abundant microscaled pores are successfully created across Cu-Mn bulks with fine-modulating the chemical properties. In sharp contrast with the compact counterparts without tailed porosity, the tuned crystallinity, accessed edge sites with the unsaturated coordination, fast redox chemistry, and boosted gaseous diffusion during reactions synergize to result in the signally good toluene oxidation, with the complete elimination activity at 252 °C, T₉₀ at 237 °C, and prominent long-term durability under the stringent reaction atmospheres. Our current study ushers in an alternative and tractable arena to excogitate the porous oxide materials for multifarious catalysis implementations.

Gram-scale synthesis of ultra-fine Cu2O for highly efficient ozone decomposition

Dozens of grams of ultra-fine Cu₂O with efficient ozone decomposition was prepared by a facile liquid phase reduction method at room temperature.

Facile solution synthesis of Cu2O–CuO–Cu(OH)2 hierarchical nanostructures for effective catalytic ozone decomposition

Cu-Based catalysts obtained at different reaction time present various morphologies, chemical compositions and ozone decomposition activities.

Low temperature decomposition of ozone by facilely synthesized cuprous oxide catalyst

The small size cubic Cu₂O exhibits high ozone catalytic performance due to the facile desorption of surface O₂²⁻ on {100} planes.

N,N′-di-caboxy methyl perylene diimide (PDI) functionalized CuO nanocomposites with enhanced peroxidase-like activity and their application in visual biosensing of H2O2 and glucose

Perylene diimide functionalized CuO nanobelts were demonstrated to possess higher intrinsic peroxidase-like activity than that of pure CuO nanobelts.

Highly dispersed copper (oxide) nanoparticles prepared on SBA-15 partially occluded with the P123 surfactant: toward the design of active hydrogenation catalysts

Mesoporous SBA-15 silica containing intra-wall embedded polymeric P123 surfactant and presenting a high density of surface silanol groups effectively stabilizes copper phases.

Freestanding three-dimensional core-shell nanoarrays for lithium-ion battery anodes

Structural degradation and low conductivity of transition-metal oxides lead to severe capacity fading in lithium-ion batteries. Recent efforts to solve this issue have mainly focused on using nanocomposites or hybrids by integrating nanosized metal oxides with conducting additives. Here we design specific hierarchical structures and demonstrate their use in flexible, large-area anode assemblies. Fabrication of these anodes is achieved via oxidative growth of copper oxide nanowires onto copper substrates followed by radio-frequency sputtering of carbon-nitride films, forming freestanding three-dimensional arrays with core–shell nano-architecture. Cable-like copper oxide/carbon-nitride core–shell nanostructures accommodate the volume change during lithiation−delithiation processes, the three-dimensional arrays provide abundant electroactive zones and electron/ion transport paths, and the monolithic sandwich-type configuration without additional binders or conductive agents improves energy/power densities of the whole electrode.

Degradation and low conductivity of transition metal oxide anodes cause capacity fading in lithium ion batteries. Here the authors make freestanding 3D copper oxide/carbon nitride core-shell nanoarrays which accommodate volume change, provide electro-active zones and facilitate rapid charge transport.

Ultrathin CuO nanorods: controllable synthesis and superior catalytic properties in styrene epoxidation

Ultrathin CuO nanorods which were synthesized in an oleylamine-based synthetic system exhibited excellent activity and high styrene oxide yields in styrene epoxidation.

A new sensing platform based on electrospun copper oxide/ionic liquid nanocomposite for selective determination of risperidone

A copper oxide nanoparticle/ionic liquid nanocomposite modified electrode exhibits excellent electrocatalytic activity towards the oxidation of risperidone.

Synthesis and microwave modification of CuO nanoparticles: crystallinity and morphological variations, catalysis, and gas sensing

CuO nanoparticles with different morphologies were synthesized by chemical precipitation and subsequently modified by microwave hydrothermal processing. The nanoparticles were precipitated by the introduction of a strong base to an aqueous solution of copper cations in the presence/absence of the polyethylene glycol and urea additives. The modification of the nanoparticles was subsequently carried out by a microwave hydrothermal treatment of suspensions of the precipitates, precipitated with and without the additives. X-ray powder diffraction analysis indicated that the crystallinity and crystallite size of the CuO nanoparticles increased after the microwave hydrothermal modification. Microscopy observations revealed the morphology changes induced by microwave hydrothermal processing. The thermal decomposition of ammonium perchlorate and the detection of volatile gases were performed to evaluate the catalytic and gas sensing properties of the synthesized CuO nanoparticles.

Low-temperature remediation of NO catalyzed by interleaved CuO nanoplates

A copper(II)-oxide-based exhaust catalyst exhibits better activity than Pt- and Rh-nanoparticle catalysts in NO remediation at 175 °C. Following theoretical design, the CuO catalyst is rationally prepared; CuO nanoplates bearing a maximized amount of the active {001} facet are arranged in interleaved layers. A field test using a commercial gasoline engine demonstrates the ability of the catalyst to remove NO from the exhaust of small vehicles.

Effects of preparation method on CeCu oxide catalyst performance

CeCu-HT, CeCu-PC, and CeCu-CA composite oxide catalysts were synthesized using hard-template, coprecipitation, and complex methods, respectively, and characterized by XRD, TEM, BET, XPS, and H₂-TPR.

Hierarchical CuO nanoflowers: water-required synthesis and their application in a nonenzymatic glucose biosensor

For the first time, a facile, one-pot water/ethanol solution-phase transformation of Cu2(NO3)(OH)3 precursors into bicomponent CuO hierarchical nanoflowers is demonstrated by a sequential in situ dissolution-precipitation formation mechanism. The first stage produces a precursory crystal (monoclinic Cu2(NO3)(OH)3) that is transformed into monoclinic CuO nanoflowers during the following stage. Water is a required reactant, and the morphology-controlled growth of CuO nanostructures can be readily achieved by adjusting the volume ratio between water and ethanol. Such a bicomponent CuO hierarchical nanoflower serving as a promising electrode material for a nonenzymatic glucose biosensor shows higher sensitivity and excellent selectivity. The findings reveal that the different Cu(x)M(y)(OH)(z) (M = acidic radical) precursors synthesized in a water/ethanol reaction environment can be utilized to obtain new forms of CuO nanomaterials, and this unique water-dependent precursor-transformation method may be used to effectively control the growth of other metal oxide nanostructures.

Facile water-assisted synthesis of cupric oxide nanourchins and their application as nonenzymatic glucose biosensor

We have demonstrated an interesting approach for the one-pot synthesis of cupric oxide (CuO) nanourchins with sub-100 nm through a sequential dissolution-precipitation process in a water/ethanol system. The first stage produces a precursory crystal [Cu7Cl4(OH)10H2O] that is transformed into monoclinic CuO nanourchins during the following stage. Water is a required reactant for the morphology-controlled growth of different CuO nanostructures. When evaluated for their nonenzymatic glucose-sensing properties, these CuO nanourchins manifest higher sensitivity. Significantly, this water-dependent precursor transformation method may be widely used to effectively control the growth of other metal oxide nanostructures.