Graphene exfoliation in cyrene for the sustainable production of microsupercapacitors

Graphene and its composites have attracted much attention for applications in energy storage systems. However, the toxic solvents required for the exfoliation process have hampered the exploitation of its properties. In this work, graphene dispersions are obtained via liquid phase exfoliation (LPE) of graphite in cyrene, an environmentally friendly solvent with solubility parameters like those…

Resonant Cavity Effect for Spectrally Tunable and Efficient Narrowband Perovskite Photodetectors

Narrowband photodetectors with precise spectral control offer significant potential for applications such as color imaging and machine vision. However, existing demonstrations have encountered challenges due to restricted absorption, the need for additional filters, or the inclusion of thick absorbing layers to facilitate charge collection filtering mechanisms. These constraints have resulted in suboptimal detectivity, inadequate color…

Computational and experimental insights into single-atom catalysts supported on g-C3N4: Unraveling the superior stability and catalytic activity of Rh in hydroformylation reactions

Single-atom catalysts (SACs) have emerged as a promising class of materials, leveraging the benefits of both homogeneous and heterogeneous catalysis to enhance efficiency and selectivity. In this work we have investigated the catalytic performance of SACs supported on graphitic carbon nitride (g-C3N4) for hydroformylation reactions. A systematic evaluation of nine transition metal SACs (Fe, Ru,…

In situ TEM and synchrotron SAXS/WAXS study on the impact of different iron salts on iron-catalysed graphitization of cellulose

Carbon materials are essential for emerging energy applications and there is a pressing need to be able to produce carbons with controlled properties from sustainable precursors. Iron-catalysed graphitization of biomass is an attractive approach, where simple iron salts are used to convert organic matter to graphitic carbons at relatively low temperature. The choice of iron…

Improving energy storage properties of carbon felt electrodes for vanadium redox flow batteries via ZIF modifications

In this study, we successfully enhanced the electrochemical energy storage properties of commercial carbon felts by modifying their surface with metal-organic frameworks (MOFs) of the zeolitic imidazolate framework (ZIF) type, incorporating Fe, Co, Ni, Cu, and Zn as metal centres. These modifications were achieved through two distinct processes: layer-by-layer deposition and a hydrothermal synthesis method.…

Thermal stability and electrical properties of XFe2O4 (X = Co,Cu,Fe,Mg,Mn Ni) high-entropy spinel ferrites prepared by reactive flash sintering

This study investigates the high-temperature stability and phase composition of two high-entropy oxides (HEOs), (Mn0.2Co0.2Ni0.2Cu0.2Fe0.2)Fe2O4 and (Mn0.2Co0.2Ni0.2Cu0.2Mg0.2)Fe2O4, prepared as single-phase samples using the reactive flash sintering technique. Results show that the annealing temperature in a nitrogen atmosphere has a significant impact on the stability of the compounds. The destabilization of the spinel structure occurs in…

Voids and nanopores in nanocolumnar platinum thin films grown by magnetron sputtering and evaporation at oblique angles: A comparative analysis

Nanocolumnar thin films deposited at oblique angle (OA) by magnetron sputtering or evaporation often show common structural aspects when grown under equivalent geometrical conditions. This is the case of the column tilt angle as a function of the geometrical deposition arrangement, which coincides for some materials no matter the technique. This feature has usually been…

Microstructure and composition evolution of He charged solid-gas nanocomposite films of different matrix elements during thermal annealing in vacuum

Sputtering of cobalt, silicon and zirconium in a helium magnetron discharge (MS) is reported as a bottom-up procedure to obtain He-charged films (i.e. He-4 and He-3 filled nanopores encapsulated in the matrix material). Composition and microstructural analyses are presented from ion beam analysis (IBA) and scanning and transmission electron microscopies (SEM and TEM). Helium desorption…