With a growing global population increasing demand for food production, fertilisers are of paramount importance in the agricultural industry. New fertiliser coating candidates may reduce environmental harm but it is critical that they are evaluated for their native biodegradation potential within agricultural soils and their effects on microbial communities. Four of the seven compounds tested, poly(1,4-butylene adipate) (PBA), polyethylene adipate (PEA), polycaprolactone (PCL) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), showed degradation by indigenous soil microorganisms with headspace CO concentrations increasing between 14 to 98 % compared to the soil only control.
View Article and Find Full Text PDFHigh intrinsic activity of oxygen evolution reaction (OER) catalysts is often limited by their low electrical conductivity. To address this, we introduce copper inverse opal (IO) frameworks offering a well-developed network of interconnected pores as highly conductive high-surface-area supports for thin catalytic coatings, for example, the extremely active but poorly conducting nickel-iron layered double hydroxides (NiFe LDH). Such composites exhibit significantly higher OER activity in 1 m KOH than NiFe LDH supported on a flat substrate or deposited as inverse opals.
View Article and Find Full Text PDFIn addition to its use in the fertilizer and chemical industries, ammonia is currently seen as a potential replacement for carbon-based fuels and as a carrier for worldwide transportation of renewable energy. Implementation of this vision requires transformation of the existing fossil-fuel-based technology for NH production to a simpler, scale-flexible technology, such as the electrochemical lithium-mediated nitrogen-reduction reaction. This provides a genuine pathway from N to ammonia, but it is currently hampered by limited yield rates and low efficiencies.
View Article and Find Full Text PDFThe instability and expense of anodes for water electrolyzers with acidic electrolytes can be overcome through the implementation of a cobalt-iron-lead oxide electrocatalyst, [Co-Fe-Pb]O , that is self-healing in the presence of dissolved metal precursors. However, the latter requirement is pernicious for the membrane and especially the cathode half-reaction since Pb and Fe precursors poison the state-of-the-art platinum H evolving catalyst. To address this, we demonstrate the invariably stable operation of [Co-Fe-Pb]O in acidic solutions through a cobalt-selective self-healing mechanism without the addition of Pb and Fe and investigate the kinetics of the process.
View Article and Find Full Text PDFMembranes are ubiquitous in nature with primary functions that include adaptive filtering and selective transport of chemical/molecular species. Being critical to cellular functions, they are also fundamental in many areas of science and technology. Of particular importance are the adaptive and programmable membranes that can change their permeability or selectivity depending on the environment.
View Article and Find Full Text PDFNanostructured materials have potential as platforms for analytical assays and catalytic reactions. Herein, we report the synthesis of electrocatalytically active cobalt phosphate nanostructures (CPNs) using a simple, low-cost, and scalable preparation method. The electrocatalytic properties of CPNs toward the electrooxidation of glucose (Glu) were studied by cyclic voltammetry and chronoamperometry in relevant biological electrolytes, such as phosphate-buffered saline (PBS), at physiological pH (7.
View Article and Find Full Text PDFProgress in understanding of energy transfer in nature and human being requires novel approaches to the processing of solids on demand, in specially those with composition gradients and those thermodynamically and kinetically inaccessible. We demonstrate that rapidly oscillating microbubbles are useful for materials processing, because they manipulate surface temperature and creates temperature gradients in predictable way. Ultrasonic treatment leads to an increase in the surface area of particles up to 180 mg and the formation of micropores in metal phase and mesopores in metal oxide phase.
View Article and Find Full Text PDFMetal-phenolic networks (MPNs) are a versatile class of organic-inorganic hybrid systems that are generating interest for applications in catalysis, bioimaging, and drug delivery. These self-assembled MPNs possess metal-coordinated structures and may potentially serve as redox-responsive platforms for triggered disassembly or drug release. Therefore, a comprehensive study of the reduction and oxidation behavior of MPNs for evaluating their redox responsiveness, specific conditions required for their disassembly, and the kinetics of metal ion release, is necessary.
View Article and Find Full Text PDFHigh intensity ultrasound (HIUS) is a novel and efficient tool for top-down nanostructuring of multi-phase metal systems. Ultrasound-assisted structuring of the phase in metal alloys relies on two main mechanisms including interfacial red/ox reactions and temperature driven solid state phase transformations which affect surface composition and morphology of metals. Physical and chemical properties of sonication medium strongly affects the structuring pathways as well as morphology and composition of catalysts.
View Article and Find Full Text PDFElucidation of the nature of hydrogen interactions with palladium nanoparticles is expected to play an important role in the development of new catalysts and hydrogen-storage nanomaterials. A facile scaled-up synthesis of uniformly sized single-crystalline palladium nanoparticles with various shapes, including regular nanocubes, nanocubes with protruded edges, rhombic dodecahedra, and branched nanoparticles, all stabilized with a mesoporous silica shell is developed. Interaction of hydrogen with these nanoparticles is studied by using temperature-programmed desorption technique and by performing density functional theory modeling.
View Article and Find Full Text PDFCrystallographic property such as crystallite size has been used for evaluation of the temperature up to which high intensity ultrasound can heat metal particles depending on physical properties of sonication medium and particle concentration. We used >100 μm metal particles as an in situ indicator for ultrasonically induced temperature in the particle interior. Based on powder X-ray diffraction monitoring of Al3Ni2 crystallite sizes after ultrasound treatment the average minimum temperature T particle(min) of sonicated particles in various sonication media was estimated.
View Article and Find Full Text PDFWe present sonogenerated magnesium-hydrogen sponges for effective reactive hard templating. Formation of differently organized nanomaterials is possible by variation of sonochemical parameters and solution composition: Fe2O3 nanorods or composite dendritic Fe2O3/Fe3O4 nanostructures.
View Article and Find Full Text PDFHigh intensity ultrasound treatment has been used to generate electrocatalytically active (toward hydrogen evolution) surface on AlNi (50 wt.% Ni) alloy particles. Acoustic cavitation is responsible for the initiation of redox processes on the catalyst surface leading to changes in its composition.
View Article and Find Full Text PDFCrystallite size of the intermetallics is one of the most important parameters that can influence kinetics of catalytic reactions. Analysis of the crystallite sizes of Al₃Ni and Al₃Ni₂ intermetallic phases using Scherrer and Williamson-Hall methods reveals that the sonomechanical impact of ultrasound on suspensions of AlNi particles in ethanol results in crystallites growth and microstrain reduction.
View Article and Find Full Text PDFUltrasound has been found useful in increasing the efficiency and consumer safety in food processing. Removal of heavy metal (lead, mercury, and arsenic) contamination in milk is extremely important in regions of poor ecological environment - urban areas with heavy motor traffic or well established metallurgical/cement industry. In this communication, we report on the preliminary studies on the application of low frequency (20kHz) ultrasound for heavy metal decontamination of milk without affecting its physical, chemical, and microbiological properties.
View Article and Find Full Text PDFIn food industry, conventional methodologies such as grinding, mixing, and heat treatment are used for food processing and preservation. These processes have been well studied for many centuries and used in the conversion of raw food materials to consumable food products. This report is dedicated to the application of a cost-efficient method of energy transfer caused by acoustic cavitation effects in food processing, overall, having significant impacts on the development of relatively new area of food processing such as food sonochemistry.
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