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Lubrication of an internal combustion engine is critical for energy and material losses. Engine lubricants contain a number of functional additives including zinc dialkyldithiophosphate, which is a...

The simultaneous removal of organic and inorganic pollutants from wastewater is a complex challenge and requires usually several sequential processes. Here, we demonstrate the fabrication of a hybrid material that can fulfill both tasks: (i) the adsorption of metal ions due to the negative surface charge, and (ii) photocatalytic decomposition of organic compounds. The bioinorganic hybrid membrane consists of cellulose fibers to ensure mechanical stability and of Bi4O5Br2/BiOBr nanosheets. The composite is synthesized at low temperature of 115 °C directly on the cellulose membrane (CM) in order to maintain the carboxylic and hydroxyl groups on the surface that are responsible for the adsorption of metal ions. The composite can adsorb both Co(II) and Ni(II) ions and the kinetic study confirmed a good agreement of experimental data with the pseudo-second-order equation kinetic model. CM/Bi4O5Br2/BiOBr showed higher affinity to Co(II) ions than to Ni(II) ions from diluted aqueous solutions. The bioinorganic composite demonstrates a synergistic effect in the photocatalytic degradation of rhodamine B (RhB) by exceeding the removal efficiency of single components. The fabrication of the biologic-inorganic interface was confirmed by various analytical techniques including scanning electron microscopy (SEM), scanning transmission electron microscopy with energy dispersive X-ray spectroscopy (STEM EDX) mapping, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The presented approach for controlled formation of the bioinorganic interface between natural material (cellulose) and nanoscopic inorganic materials of tailored morphology (Bi–O–Br system) enables the significant enhancement of materials functionality.

Cobalt-based Li-ion batteries are produced globally on a massive scale, but most are discarded to landfill at the end of their useful lifetime. In this work, an efficient cobalt catalyst for the hydrolysis of sodium borohydride to dihydrogen was prepared from lithium ion battery waste, providing a second life for valuable minerals. This material is composed of a mixed metal cobalt–aluminium oxide supported on graphene, as elucidated by a combined FTIR, Raman, SEM, scanning transmission electron microscopy with electron energy loss spectroscopy (STEM-EELS) and energy-dispersive X-ray spectroscopy (EDS) study. The obtained metal oxide material, which exhibits an average oxidation state for Co of 2.45, is a languid catalyst at room temperature, but rapid hydrogen production of up to 49 L(H2) min−1 g−1(Co) was observed in catalytic runs heated to 70 °C. This carbon-supported cobalt catalyst is competitive with designed cobalt nanostructured catalysts prepared from pure precursors. This work is illustrative of the opportunities which arise when e-waste is utilised as a mineral resource within the scope of a circular economy.

Lubrication of an internal combustion engine is critical for unwanted energy and material losses. Zinc dialkyldithiophosphate (ZDDP) is a commonly used anti-wear additive that forms by in situ decomposition a protecting interface between sliding surfaces. The interface consists of the tribofilm on both surfaces and oil in the contact. Soot particles from a petrol engine and gas engine were analyzed using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques: electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDS). These techniques revealed that the end-products in soot contain 3-5 nm ZnO-based particles with additions of phosphorus and sulfur, originating from the ZDDP anti-wear additive. Our results unravel the tribofilm decomposition under real field conditions and hint toward potentially unidentified hazards with respect to ZDDP-containing lubricants.

CuWO4 is a photoanode candidate in neutral pH, and manganese-based oxygen evolution reaction electrocatalysts are of high interest due to their low price and low toxicity. Considering the unexplored chemistry of transition-metal carbodiimides/cyanamides for the PEC water oxidation, we investigated MnNCN as an electrocatalyst for CuWO4 under AM 1.5G illumination in potassium phosphate electrolyte (pH 7). Surface functionalization of CuWO4 photoanodes with MnNCN increased the photocurrent from 22 to 30 μA cm-2 at 1.23 V vs RHE. Complementary structural analysis by means of XRD and XPS revealed that MnNCN forms a core-shell structure MnNCN@MnPO x in phosphate electrolyte and mimics a manganese phosphate electrocatalyst. As such, the surface chemistry of MnNCN significantly differs from previous studies on the cobalt analogue (CoNCN). A separately prepared MnNCN electrode developed a small but detectable photocurrent due to photogenerated holes inside the semiconducting carbodiimide core of the MnNCN@MnPO x structure.

With nanostructured materials such as catalytic heterostructures projected to play a critical role in applications ranging from water splitting to energy harvesting, tailoring their properties to specific tasks requires an increasingly comprehensive characterization of their local chemical and electronic landscape. Although aberration-corrected electron spectroscopy currently provides sufficient spatial resolution to study this space, an approach to concurrently dissect both the electronic structure and full composition of buried metal/oxide interfaces remains a considerable challenge. In this manuscript, we outline a statistical methodology to jointly analyze simultaneously-acquired STEM EELS and EDX datasets by fusing them along their shared spatial factors. We show how this procedure can be used to derive a rich descriptive model for estimating both transition metal valency and full chemical composition from encapsulated morphologies such as core-shell nanoparticles. We demonstrate this on a heterogeneous Co-P thin film catalyst, concluding that this system is best described as a multi-shell phosphide structure with a P-doped metallic Co core.

Alkaline earth monosilicides (AESi, AE = Ca, Sr, Ba) are poor metals, and their transport properties are not solely determined by the Zintl anion, in contrast to their Zintl-type composition. Their conducting network is formed by the depopulated ∞1[Si2−] π system and AE-d states. This justifies the special local coordination of the metal atoms and the planarity of the silicon chains. The low density of carriers seems to be a playground for magnetic instabilities and the triangular prismatic arrangement of AE atoms responsible for the observed weak glassy behavior.

In our search for clathrates containing rare-earth elements we have discovered the three new clathrate-I phases K 6 Eu 2 Ga 10 Ge 36 , K 6 Eu 2 Zn 5 Ge 41 , and K 6 Eu 2 Cd 5 Ge 41 . The Eu atoms occupy only the smaller cages (pentagondodecahedra) leading to a fully ordered arrangement of the guest atoms. X-ray absorption spectroscopy and magnetic susceptibility measurements reveal that at room temperature and above Eu is close to divalent in all compounds. Magnetization measurements at low temperatures, however, may indicate slightly reduced magnetic moments for K 6 Eu 2 Ga 10 Ge 36 and K 6 Eu 2 Zn 5 Ge 41 . The ferromagnetic ordering temperatures of 3.8, 4.0, and 9.3 K for K 6 Eu 2 Ga 10 Ge 36 , K 6 Eu 2 Zn 5 Ge 41 , and K 6 Eu 2 Cd 5 Ge 41 , respectively, are considerably reduced with respect to the 36 K observed for the type-I clathrate β - Eu 8 Ga 16 Ge 30 where all cages are occupied by Eu.

Jede Menge Lithium: Die Silicide Li7CuSi2, mit dem linearen Zintl-Anion [Si-Cu-Si]7− (siehe Bild), und Li7.3CuSi3 sind die Verbindungen mit dem hochsten Lithiumgehalt in diesem ternren System. Die Kristallstrukturen und Bindungsverhltnisse beider Verbindungen werden besprochen.

Materials with a low degree of space filling may have low thermal conductivity. If combined with the enhanced thermopower, often observed in strongly correlated rare-earth or transition metal containing materials, this may result in a material with superior thermoelectric properties for cooling applications. YbGa6Te10 is a new rare-earth containing material. The thermal conductivity of this compound is very low and is explained in terms of low degree of space filling, large unit cell and relatively heavy elements. The very low thermal conductivity makes this compound or similar modifications a potential candidate for a strongly correlated thermoelectric material.