Evaporation-induced self-assembling of few-layer graphene into a fractal-like conductive macro-network with a reduction of percolation threshold.

The transcription of nanoproperties to other dimensions in an efficient and simple way by the appropriate design of devices is a challenge, and conductive nanocarbon systems are considered here. The evaporation-induced self-assembling method is proposed to form branched, fractal-like "2D" conductive macrostructures from (nano) micro few-layer graphene flakes. The self-assembled conductive graphene networks reveal a reduction of percolation threshold compared to a random arrangement (a lower matter concentration is required to make a given substrate conductive and at a lower coverage), and become a promising matrix for conductive (transparent) films. The method is easy, cost-efficient and can potentially be applied on unlimited surfaces.

Few-layered graphene-supported palladium as a highly efficient catalyst in oxygen reduction reaction.

New, active and stable catalysts competitive to Pt catalysts are necessary for fuel cell development. Here, we present few-layered graphene-supported Pd, revealing a performance superior to Pt/C and Pd/C ORR (positive half-wave potential shift E(1/2) by 50 mV, approximately one order of magnitude higher area- and mass-normalized current densities, I(area), I(mass), after 2500 cycles). The catalyst preparation is easily scalable, simple, inexpensive and eco-friendly.

A 3D insight on the catalytic nanostructuration of few-layer graphene.

The catalytic cutting of few-layer graphene is nowadays a hot topic in materials research due to its potential applications in the catalysis field and the graphene nanoribbons fabrication. We show here a 3D analysis of the nanostructuration of few-layer graphene by iron-based nanoparticles under hydrogen flow. The nanoparticles located at the edges or attached to the steps on the FLG sheets create trenches and tunnels with orientations, lengths and morphologies defined by the crystallography and the topography of the carbon substrate. The cross-sectional analysis of the 3D volumes highlights the role of the active nanoparticle identity on the trench size and shape, with emphasis on the topographical stability of the basal planes within the resulting trenches and channels, no matter the obstacle encountered. The actual study gives a deep insight on the impact of nanoparticles morphology and support topography on the 3D character of nanostructures built up by catalytic cutting.

Accumulation of cadmium in and its effect on bank vole tissues after chronic exposure.

Cadmium is one of many metals that are not physiologically or biochemically essential to organisms. This element is extremely dangerous as it is easily absorbed and remains in tissues for a long time. Long exposure to high doses of cadmium may cause biochemical and functional changes in some critical organs. In this study, wheat grains contaminated with cadmium chloride were used to test the influence of cadmium on male bank voles (Clethrionomys glareolus). Doses used in the experiment were environmentally realistic: 0.25 microg g-1 (control), 15 microg g-1, and 40 microg g-1 cadmium (dry weight). The animals were given cadmium-contaminated food and clean water ad libitum for 3 and 6 months. After these exposures, the animals were killed and the kidneys, liver, and testes from each vole were collected for analyses. The concentrations of Cd, Cu, Zn, and Fe in the tissues were determined with an atomic absorption spectrophotometer. The formalin-fixed testes, kidneys, and part of the liver were embedded in paraffin and then stained with hematoxylin and eosin. Cadmium accumulation in the tissues was directly proportional to dose. The highest cadmium concentrations were found in the kidneys of animals fed the highest dose of cadmium. Histological examination of the tissues revealed some pathological changes in the structure of kidneys, liver, and testes.