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Nanoengineered nanoparticles have a significant impact on the morphological, physiology, biochemical, cytogenetic, and reproductive yields of agricultural crops. Metal and metal oxide nanoparticles like Ag, Au, Cu, Zn, Ti, Mg, Mn, Fe, Mo, etc. and ZnO, TiO2, CuO, SiO2, MgO, MnO, Fe2O3 or Fe3O4, etc. that found entry into agricultural land, alter the morphological, biochemical and physiological system of crop plants. And the impacts on these parameters vary based on the type of crop and nanoparticles, doses of nanoparticles and its exposure situation or duration, etc. These nanoparticles have application in agriculture as nanofertilizers, nanopesticides, nanoremediator, nanobiosensor, nanoformulation, phytostress-mediator, etc. The challenges of engineered metal and metal oxide nanoparticles pertaining to soil pollution, phytotoxicity, and safety issue for food chains (human and animal safety) need to be understood in detail. This review provides a general overview of the applications of nanoparticles, their potentials and challenges in agriculture for sustainable crop production. [ABSTRACT FROM AUTHOR]

Because of their unique physical and chemical properties, one-dimensional (1-D) metal-oxide nanostructures have been extensively applied in the areas of gas sensors, electrochromic devices, nanogenerators, and so on. Solar water-splitting has attracted extensive research interest because hydrogen generated from solar-driven water splitting is a clean, sustainable, and abundant energy source that not only solves the energy crisis, but also protects the environment. In this comprehensive review, the main synthesis methods, properties, and especially prominent applications in solar water splitting of 1-D metal-oxides, including titanium dioxide (TiO), zinc oxide (ZnO), tungsten trioxide (WO), iron oxide (FeO), and copper oxide (CuO) are fully discussed. [ABSTRACT FROM AUTHOR]

The catalytic reactivity and selectivity of metallic nanoclusters supported on a metal-oxide can be tuned by electronic charge. In this review, different approaches for controlling the electronic properties of metallic nanoclusters and its impact on catalytic reactions are discussed. Electronic charge can transfer from the metal-oxide support to the metallic catalyst and change the metal-reactants interaction and as a consequence modify as-well the catalytic reactivity and selectivity. In other cases, the electronic properties of the metal-oxide have an active role in the catalytic process and the metal oxide can be used as a co-catalyst. Another approach is to directly change the electronic properties of the metallic catalyst. It is demonstrated that dendrimer-encapsulated metallic nanoparticles can be directly oxidized by the addition of an inorganic oxidizer to the solution phase. In this case, even while supported on inert oxides, novel catalytic reactivity and selectivity can be gained by the formation of highly oxidized metal ions. [ABSTRACT FROM AUTHOR]

Atomic layer deposition (ALD) was used to deposit TiO on Ni particles, and the catalytic activity of Ni for CO reforming of methane (CRM) was evaluated. In the presence of TiO islands on Ni surfaces, the onset temperature of the CRM reaction was lower than that of bare Ni. During the CRM reaction, carbon was deposited on the surface of bare Ni, which reduced the catalytic activity of the surface with time, and TiO islands were able to remove carbon deposits from the surface. When the Ni surface was completely covered with TiO, the catalytic activity disappeared, demonstrating that tuning of the TiO coverage on Ni is important to maximize the activity of the CRM reaction. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Nanocrystalline cubic fluorite/bixbyite CeO or α-MnO has been successfully synthesized by using methanol as a solvent via sol-gel method calcined at 400 °C. The obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis absorption and Photoluminescence (PL) spectroscopy. TEM reveals that the as-synthesized ultra-fine samples consist of elliptical/spherical and sheet-like morphology of crystalline particles of 8/30 nm, which are weakly aggregated. Optical absorbance spectra reveal that the absorption of ceria in the UV region originates from the charge- transfer transition between the O (2p) and Ce (4f) orbit in CeO. However, α-MnO nanostructures with nearly pure band gap emission should be of importance for their applications as UV emitters. [ABSTRACT FROM AUTHOR]

The interest in first principles investigations of metal-oxide surfaces has been growing rapidly over the past 10 years. Several phenomena of vital importance for fundamental understanding of heterogeneous catalysis have been investigated, including the metal/metal-oxide interface and the interaction with adsorbates. This contribution reviews different implementations of the density functional theory frequently used in studies of metal-oxide properties. Computational results are discussed and compared to experimental data. [ABSTRACT FROM AUTHOR]

The nano-sized metal-oxide ultrafine powders of the low-melting-point metals can be prepared rapidly using a new atomizing - combustion technique by which the superheated metal melt was atomized with a ceramic atomizing-burner first through the medium of high pressure oxygen, then the metal fog burned up in a combustion chamber. Based on the experiments, nano-sized SnO2, In2O3 and Bi2O3 powders were obtained successfully by atomizing-combustion technique. The mechanism and process parameters of the technique were discussed. The phase structure and the microstructure of these metal-oxide ultrafine powders were studied by XRD and TEM respectively. The biggest size of grain was less than 50 nm, and 1 kg metal-oxide ultrafine powder can be prepared in only 45–48 seconds. [ABSTRACT FROM AUTHOR]