Seawater desalination is a worldwide concern for the sustainable production of drinking water. In this regard, membrane distillation (MD) has shown the potential for effective brine treatment. However, the lack of appropriate MD membranes limits its industrial expansion since they experience fouling and wetting issues. Therefore, hydrophobic membranes are promising candidates to successfully deal with such phenomena that are typical for commercially available membranes. Here, several graphene/polyvinylidene (PVDF_G) membranes with different graphene loading (0–10 wt%) were prepared through a phase inversion method. After full characterization of the resulting membranes, the surface revealed that the well-dispersed graphene in the polymer matrix (0.33 and 0.5 wt% graphene loading) led to excellent water repellence together with a rough structure, and a large effective surface area. Importantly, antifungal activity tests of films indicated an increase in the inhibition percentage for PVDF_G membranes against the Curvularia sp. fungal strain. However, the antifungal surface properties were found to be the synergistic result of graphene toxicity and surface topography.
Slightly processed raw data for the paper 'Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study' The processing include a spike removal to allow an interpolation to a common wavenumber axis. Always three files belong to each other: wavenumber axis file (wx_XYZ), spectral intensity file (spec_XYZ) and metadata file (meta_XYZ). The ‘XYZ’ refers to the samples measured (see the publication and its SI for details).
In this work, the influence of the synthesis conditions on the structure, morphology, and electrocatalytic performance for the oxygen evolution reaction (OER) of Mn-Co-based films is studied. For this purpose, Mn-Co nanofilm is electrochemically synthesised in a one-step process on nickel foam in the presence of metal nitrates without any additives. The possible mechanism of the synthesis is proposed. The morphology and structure of the catalysts are studied by various techniques including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analyses show that the as-deposited catalysts consist mainly of oxides/hydroxides and/or (oxy)hydroxides based on Mn2+, Co2+, and Co3+. The alkaline post-treatment of the film results in the formation of Mn-Co (oxy)hydroxides and crystalline Co(OH)2 with a β-phase hexagonal platelet-like shape structure, indicating a layered double hydroxide structure, desirable for the OER. Electrochemical studies show that the catalytic performance of Mn-Co was dependent on the concentration of Mn versus Co in the synthesis solution and on the deposition charge. The optimised Mn-Co/Ni foam is characterised by a specific surface area of 10.5 m2·g-1, a pore volume of 0.0042 cm3·g-1, and high electrochemical stability with an overpotential deviation around 330-340 mV at 10 mA·cm-2geo for 70 h.
The variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.
Simple thermal decomposition of low-cost precursors in an inert atmosphere leads to mesoporous nitrogen-doped carbon nanosheets with electrocatalytic activity towards ORR.
The prevalence of the antibiotic resistant bacteria remains a global issue. Cheap, sustainable and multifunctional antibacterial membranes are at the forefront of filtrating materials capable of treating multiple flow streams, such as water cleansing treatments. Carbon nanomaterials are particularly interesting objects shown to enhance antibacterial properties of composite materials. In this article, amino-functionalized, photoluminescent carbon nanodots (CNDs) were synthesized from chitosan by bottom-up approach via simple and green hydrothermal carbonization. A chemical model for the CNDs formation during hydrothermal treatment of chitosan is proposed. The use of urea as an additional nitrogen source leads to the consumption of hydroxyl groups of chitosan and higher nitrogen doping level as pyridinic and pyrrolic N-bonding configurations in the final carbonaceous composition. These functionalized carbon nanodots that consist of carbon core and various surface functional groups were used to modify the commercially available membranes in order to enhance their anti-biofouling properties and add possible functionalities, including fluorescent labelling. Incorporation of CNDs to membranes increased their hydrophilicity, surface charge without compromising membranes integrity, thereby increasing the factors affecting bacterial wall disruption. Membranes modified with CNDs effectively stopped the growth of two Gram-negative bacterial colonies: Klebsiella oxytoca (K. oxytoca) and Pseudomonas aeruginosa (P. aeruginosa).