Research in the field of aluminum batteries has focused heavily on electrodes made of carbonaceous materials. Still, the capacities reported for these multivalent systems remain stubbornly low. It is ...believed that a high structural quality of graphitic carbons and/or specific surface areas of >1000 m2 g‐1 are key factors to obtain optimal performance and cycling stability. Here an aluminum chloride battery is presented in which reduced graphene oxide (RGO) powder, dried under supercritical conditions, is used as the active cathode material and niobium foil as the current collector. With a specific surface area of just 364 m2 g‐1, the RGO enables a gravimetric capacity of 171 mAh g‐1 at 100 mA g‐1 and remarkable stability over a wide range of current densities (<15% decrease over 100 cycles in the interval 100–20000 mA g‐1). These properties, up to now achieved only with much larger surface area materials, result from the cathode's tailored mesoporosity. The 20 nm wide mesopores facilitate the movement of the chloroaluminate ions through the RGO, effectively minimizing the inactive mass content of the electrode. This more than compensates for the ordinary micropore volume of the graphene powder.
Tailoring the pore size distribution of carbon‐based cathodes is a decisive factor for the electrochemical performance of aluminum batteries. Here, the mesopores in a reduced graphene oxide powder facilitate the movement of large chloroaluminate ions, effectively minimizing the inactive mass content of the electrode and compensating for an ordinary micropore volume.
Advances in process intensification in the chemical and pharmaceutical industry depends on the availability of more sustainable separation methods. For this progress, membranes with high stability in ...organic solvents are needed. GO-coated membranes could be advantageous in these applications, being chemically, thermally and mechanically stable. However, simple, scalable, low-cost fabrication methods, particularly for GO deposition on hollow fibers are still in an early phase. We propose here a simple spray-coating method for deposition of GO sheets on crosslinked hollow fiber supports. We first fabricated polyetherimide hollow fiber membranes and crosslinked them with hexamethylene diamine. These supports have strong tolerance to various organic solvents. The amide reaction arising between the imide groups of polyetherimide and the amine groups of hexamethylene diamine provide even higher chemical and mechanical stability. Thereafter, the spray-coating of GO dispersions led to the formation of a stable selective layer on the hollow fibers. An excellent adhesion between GO and the substrate was achieved. The chemical reasons for that were investigated by solid state NMR. Overall, this simple method enables the application of GO hollow fiber membranes in organic solvent nanofiltration, with high performance demonstrated in water and acetone.
•Spray-coating applied for GO-layered hollow fibers.•Scalable GO hollow fibers tested for nanofiltration.•Solid-state NMR characterization of crosslinked membranes.•Solvent-resistant GO-layered hollow fibers.
Tailoring the pore size distribution of carbon‐based cathodes is a decisive factor for the electrochemical performance of aluminum batteries. In article number 1803584, Pedro M. F. J. Costa and ...co‐workers show how the mesopores in a reduced graphene oxide powder facilitate the movement of large chloroaluminate ions, effectively minimizing the inactive mass content of the electrode and compensating for an ordinary micropore volume.
Ultraviolet (UV) photodetectors often suffer from the lack of spectral selectivity due to strong interference from visible light. In this study, the exceptional electrical properties of graphene and ...the unique optical properties of carbon nitride thin films (CNTFs) are used to design visible‐blind UV photodetectors. First, polycrystalline CNTFs with different thicknesses (12–94 nm) are produced by thermal vapor condensation. Compared to the bulk carbon nitride powder, these films have a considerable sp2 nitrogen deficiency, which is thickness dependent. In addition to showing a wider bandgap than the bulk counterpart, their optical absorption profile (in the ultraviolet–visible range) is unique. Critically, the absorbance falls sharply above 400 nm, making the CNTFs suitable for ultraviolet photodetection. As a result, graphene field‐effect transistors (GFETs) sensitized with CNTFs show 103 A W−1 responsivity to UV radiation, a stark contrast to the negligible value obtained in the visible spectrum. The effect of film thickness on the photoresponse is determined, with the thinner CNTF leading to much better device performance. The CNTF/GFET photodetectors are also characterized by their fast response and recovery times, 0.5 and 2.0 s, respectively. These findings pave a simple route for the development of sensitive, visible‐blind UV photodetectors.
Carbon nitride thin films (CNTFs) of various thicknesses are deposited by thermal vapor condensation and transferred by water‐assisted method. The visible‐blind ultraviolet (UV) photodetector, fabricated by sensitizing graphene field effect transistors with CNTFs, shows 103 A W−1 responsivity to UV radiation at a switching and visible light rejection ratio of 157 and 48.2, respectively.
Background: Asthma is associated with high morbidity and mortality in India. This survey was undertaken to explore the perspectives of pulmonologists towards in-clinic management of patients with ...asthma.
Methods: It was a cross-sectional survey of pulmonologists conducted across India. It was formulated to provide unbiased observations of real-world clinical practice focusing on methods of diagnosis of asthma and its treatment preferences.
Results: The participants included 805 pulmonologists, with the majority primarily treating patients with asthma (62%), chronic obstructive pulmonary disease (19%) and allergic rhinitis (19%). More than 86% of pulmonologists consider clinical symptoms, history of childhood asthma, family history, and chronic allergic rhinitis for initial diagnosis. About 19-23% prefer spirometry alone or in combination with family history for confirmation of asthma. The preferred inhaled corticosteroids-long-acting bronchodilator (ICS-LABA) combination was budesonide-formoterol amongst 83% of pulmonologists. For both dry powder inhaler (DPI) and metered dose inhaler (MDI) devices, fine particle fraction per cent and delivered dose were ranked as the two most important attributes.
Conclusions: Asthma is the most prevalent diagnosis among patients treated by pulmonologists on the basis of clinical presentation and medical history. The most commonly used pharmacotherapy for the treatment of asthma comprises ICS-LABA, with budesonide-formoterol being the preferred combination. Fine particle fraction per cent and magnitude of delivered dose influence the choice of asthma inhaler prescriptions the most.
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