BINA

The current work delivers preparation of MXene-based magnetic nanohybrid coating for flexible electronic applications. Herein, we report carbon dot-triggered photopolymerized polynorepinepherene (PNE)-coated MXene and iron oxide hybrid deposited on the cellulose microporous membrane via a vacuum-assisted filtration strategy. The surface morphologies have been monitored by scanning electron microscopy analysis, and the coating thickness was evaluated by the gallium-ion-based focused ion beam method. Coated membranes have been tested against uniaxial tensile stretching and assessed by their fracture edges in order to assure flexibility and mechanical strength. Strain sensors and electromagnetic interference (EMI) shielding have both been tested on the material because of its electrical conductivity. The bending strain sensitivity has been stringent because of their fast ‘rupture and reform …

As highlighted by the recent roadmaps from the European Union and the United States, water electrolysis is the most valuable high‐intensity technology for producing green hydrogen. Currently, two commercial low‐temperature water electrolyzer technologies exist ‐ alkaline water electrolyzer (A‐WE) and proton exchange membrane water electrolyzer (PEM‐WE). However, both have major drawbacks. A‐WE shows low productivity and efficiency, while PEM‐WE uses a significant amount of critical raw materials. Lately, the use of anion‐exchange membrane electrolyzers (AEM‐WE) has been proposed to overcome the limitations of the current commercial systems. AEM‐WE could become the cornerstone to achieve an intense, safe and resilient green hydrogen production to fulfill the hydrogen targets to achieve the 2050 decarbonization goals. Here we discuss the status of AEM‐WE development, with a focus on …

Copper chalcogenides have attracted attention due to their intrinsic doping properties. These materials display high carrier concentrations due to their defect-heavy structures, thus by varying their stoichiometry tunable plasmonic resonances can be observed, as it was shown previously for Cu 2-x S/Se/Te, with 09S 5 were studied by means of ultrafast transient absorption (TA) spectroscopy. The samples were pumped at 50 kHz with 50 fs pulses centered a 1.65 μm, in the region of the near-infrared (NIR) plasmonic resonance, and probed in the 1.1-1.6 μm range. The measurement was performed with a high sensitivity TA spectrometer utilizing a birefringent delay line interferometer and lock-in detection, avoiding the need for expensive IR multi-pixel detectors. We were able to measure the relaxation dynamics of the excited electrons, which are dominated by a fast decay (τ 1~ 400 fs) associated to electron-phonon …

Considering the toxicity of lead ions, substituting Pb with nontoxic elements in halide perovskites, HaPs, has become one of the most significant challenges associated with these materials. Here, we report on replacing Pb with Sn and Ge, focusing on an all-inorganic HaP, CsSnxGe1–xBr3, and using a multihead spray deposition setup for thin-film formation to overcome the low solubility of the precursors and improve film coverage. We find that, in this way, we can form CsSnxGe1–xBr3 films up to high x values as homogeneous solid solutions; i.e., we obtain a range of compositions with one crystal structure (rather than clusters of two phases). The cubic structure of pure CsSnBr3 is maintained up to 77 atom % Ge, with the lattice spacing decreasing with increasing Ge concentration. The optical band gap is tunable between 1.8 and 2.5 eV, from pure Sn to pure Ge HaP. Most importantly, the perovskite structural …

Functional surface coatings were applied on high voltage spinel (LiNi0.5Mn1.5O4; LNMO) and Ni-rich (LiNi0.85Co0.1Mn0.05O2; NCM851005) NCM cathode materials using few-layered 2H tungsten diselenide (WSe2). Simple liquid-phase mixing with WSe2 in 2-propanol and low-temperature (130 °C) heat treatment in nitrogen flow dramatically improved electrochemical performance, including stable cycling, high-rate performance, and lower voltage hysteresis in Li coin cells at 30 and 55 °C. Significantly improved capacity retention at 30 °C [Q401/Q9 of 99% vs 38% for LNMO and Q322/Q23 of 64% vs 46% for NCM851005] indicated efficient functionality. TEM and XPS clarified the coating distribution and coordination with the cathode surface, while postcycling studies revealed its sustainability, enabling lower transition metal dissolution and minor morphological deformation/microcrack formation. A modified and …

Enormous potential loss and sluggish kinetics of the oxygen evolution reaction (OER) limit the practical implementation of water electrolyser systems. We attempt to address these technical challenges through the synthesis of cobalt–chromium-layered double hydroxide nanosheets (CoCr LDH) on oxidized-carbon nanotube (O-CNT) backbones as efficient OER electrocatalysts. Microscopic and elemental distribution analysis suggests that interconnected sheets of CoCr LDH masks over O-CNTs. We tested various compositions of the CoCr LDH_O-CNT hybrid (by varying the molar ratios of Co and Cr) along with the weight adjustment between CoCr LDH and O-CNTs to obtain an optimal OER activity. Due to the synergistic effect, the CoCr-LDH(3:1)_O-CNT (2:1) exhibits the lowest overpotential of 290 mV at 10 mA cm–2 with a corresponding smaller Tafel slope of 42 mV dec–1, which outperforms the other tested …

High-energy cathode materials that are Li- and Mn-rich lithiated oxides—for instance, 0.35Li2MnO3.0.65LiNi0.35Mn0.45Co0.20O2 (HE-NCM)—are promising for advanced lithium-ion batteries. However, HE-NCM cathodes suffer from severe degradation during cycling, causing gradual capacity loss, voltage fading, and low-rate capability performance. In this work, we applied an effective approach to creating a nano-sized surface layer of Li2SO4 on the above material, providing mitigation of the interfacial side reactions while retaining the structural integrity of the cathodes upon extended cycling. The Li2SO4 coating was formed on the surface of the material by mixing it with nanocrystalline Li2SO4 and annealing at 600 °C. We established enhanced electrochemical behavior with ~20% higher discharge capacity, improved charge-transfer kinetics, and higher rate capability of HE-NCM cathodes due to the presence of the Li2SO4 coating. Online electrochemical mass spectrometry studies revealed lower CO2 and H2 evolution in the treated samples, implying that the Li2SO4 layer partially suppresses the electrolyte degradation during the initial cycle. In addition, a ~28% improvement in the thermal stability of the Li2SO4-treated samples in reactions with battery solution was also shown by DSC studies. The post-cycling analysis allowed us to conclude that the Li2SO4 phase remained on the surface and retained its structure after 100 cycles.

Rechargeable Li metal batteries (LMBs) have attracted wide attention as promising candidates for the next generation of energy-storage systems. However, limited Coulombic efficiency and unregulated dendrite growth restrict its application. Here, we report a kind of electrolyte by introducing fluorinated aromatic diluents into high-concentration electrolytes (HCEs). Unlike other localized HCEs, the fluorinated aromatic diluents pairing with anions promote the formation of a homogeneous and robust solid–electrolyte interphase (SEI), which endows Li metal with an ultrahigh Coulombic efficiency of ∼99.8%. The Li||LiNi0.8Co0.1Mn0.1O2 battery holds a capacity retention of >80% over 260 cycles even with a thin Li anode (20 μm) and a high cathode loading (3.5 mAh cm–2). A 1.8 Ah Li||NMC811 pouch cell with a lean electrolyte delivers an energy density of 340 Wh kg–1 and a stable cycling life over 200 cycles. The …

Highly reflective crystals of the nucleotide base guanine are widely distributed in animal coloration and visual systems. Organisms precisely control the morphology and organization of the crystals to optimize different optical effects, but little is known about how this is achieved. Here we examine a fundamental question that has remained unanswered after over 100 years of research on guanine: what are the crystals made of? Using solution-state and solid-state chemical techniques coupled with structural analysis by powder XRD and solid-state NMR, we compare the purine compositions and the structures of seven biogenic guanine crystals with different crystal morphologies, testing the hypothesis that intracrystalline dopants influence the crystal shape. We find that biogenic “guanine” crystals are not pure crystals but molecular alloys (aka solid solutions and mixed crystals) of guanine, hypoxanthine, and …

Carbon dots (CDs) with an average diameter of 2.3 ± 0.5 nm were prepared from red cabbage by a facile one‐step hydrothermal process. The CDs and polydopamine (PDA) were then subjected to ultrasonication to form a polymer composite namely, PDA‐doped CDs (PDA@CDs). The PDA@CDs with an average size of 5 μm was proven as effective adsorbents for p‐chlorophenol (p‐CP) and p‐cyanophenol (p‐CNP) as two probing models. The adsorption capacity of PDA@CDs was estimated to be 153 mg/g for p‐CP and 178 mg/g for p‐CNP, compared favorably with those of various adsorbents used in the literature, only 24–123 mg/g. The PDA@CDs significantly improved the adsorption rate of the two phenols at neutral pH and room temperature. The adsorption kinetics was governed by the pseudo second‐order and intraparticle diffusion models. The PDA@CDs were reused as an active adsorbent …

Bone is a fascinating biomaterial comprised mostly of type-I collagen fibers as an organic phase, apatite as an inorganic phase, with water molecules residing at the interfaces between these phases. They are hierarchically organized with minor constituents such as non-collagenous proteins, citrate ions and glycosaminoglycans into a composite structure that is mechanically durable yet contains enough porosity to accommodate cells and blood vessels. The nanometer scale organization of the collagen fibrous structure and the mineral constituents in bone were recently extensively scrutinized. However, molecular details at the lowest hierarchical level still need to be unraveled to better understand the exact atomic-level arrangement of all these important components in the context of the integral structure of the bone. In this report, we unfold some of the molecular characteristics differentiating between two load …

Recent advances in focused ion beam (FIB) technology exploit accelerated helium or neon ions, rather than gallium, for maskless fabrication of superconducting nanocomponents. We present a study of the effect of the damage induced by the accelerated ions on the superconducting transition temperature, Tc, of a patterned ~ 85-nm-wide Nb wire, demonstrating a decrease of Tc from ~ 5.5 K in the wire patterned by He ions to ~ 2.8 and 2.3 K exploiting Ne and Ga ions, respectively. In an effort to gain insight into the origin of these changes in Tc, we performed Stopping and Range of Ions in Matter (SRIM) simulations to estimate the damage induced by each type of ion. The simulations show that the lateral distribution of the ion beam and the sputtering rate in using Ne or Ga are significantly larger than those caused by He, consistent with the changes in the measured electrical properties of the nanowire.

Enormous potential loss and sluggish kinetics of the oxygen evolution reaction (OER) limit the practical implementation of water electrolyser systems. We attempt to address these technical challenges through the synthesis of cobalt–chromium-layered double hydroxide nanosheets (CoCr LDH) on oxidized-carbon nanotube (O-CNT) backbones as efficient OER electrocatalysts. Microscopic and elemental distribution analysis suggests that interconnected sheets of CoCr LDH masks over O-CNTs. We tested various compositions of the CoCr LDH_O-CNT hybrid (by varying the molar ratios of Co and Cr) along with the weight adjustment between CoCr LDH and O-CNTs to obtain an optimal OER activity. Due to the synergistic effect, the CoCr-LDH(3:1)_O-CNT (2:1) exhibits the lowest overpotential of 290 mV at 10 mA cm–2 with a corresponding smaller Tafel slope of 42 mV dec–1, which outperforms the other tested …

High-energy cathode materials that are Li- and Mn-rich lithiated oxides—for instance, 0.35Li2MnO3.0.65LiNi0.35Mn0.45Co0.20O2 (HE-NCM)—are promising for advanced lithium-ion batteries. However, HE-NCM cathodes suffer from severe degradation during cycling, causing gradual capacity loss, voltage fading, and low-rate capability performance. In this work, we applied an effective approach to creating a nano-sized surface layer of Li2SO4 on the above material, providing mitigation of the interfacial side reactions while retaining the structural integrity of the cathodes upon extended cycling. The Li2SO4 coating was formed on the surface of the material by mixing it with nanocrystalline Li2SO4 and annealing at 600 °C. We established enhanced electrochemical behavior with ~20% higher discharge capacity, improved charge-transfer kinetics, and higher rate capability of HE-NCM cathodes due to the presence of the Li2SO4 coating. Online electrochemical mass spectrometry studies revealed lower CO2 and H2 evolution in the treated samples, implying that the Li2SO4 layer partially suppresses the electrolyte degradation during the initial cycle. In addition, a ~28% improvement in the thermal stability of the Li2SO4-treated samples in reactions with battery solution was also shown by DSC studies. The post-cycling analysis allowed us to conclude that the Li2SO4 phase remained on the surface and retained its structure after 100 cycles.

Catalyst poisoning and leaching is a problem faced in almost all catalyst applications. A specific technology where catalyst poisoning and leaching are a major concern is the hydrogen bromine redox flow battery (H 2–B r 2 RFB), one of the most promising energy storage technologies. However, it is currently hindered through degradation of the hydrogen oxidation/evolution catalyst, caused by B r−/B r 3− which have crossed the membrane. To prevent this degradation, Pt nanoparticles were synthesized inside 2 nm single-walled carbon nanotubes (SWCNTs). Electrochemical and spectroscopic techniques show that the Pt@ SWCNT has a vastly improved stability and higher mass activity over a commercial 50% Pt/C catalyst. Density functional theory (DFT) calculations show that the stability results from the selective diffusion of H 2 and H+ over the B r− and B r 3− species through the SWCNT to the Pt catalyst …

Similarly to other transition metal sulfides, nickel sulfide nanocrystals can be potentially used for functional device applications. However, controlling morphology and stoichiometry to target specific applications is a synthesis challenge. In this work we developed a rapid, one-step, chemical vapor deposition synthesis of nickel sulfide dendritic nanostructures with fractal geometry. Microtome-EDS compositional analysis of the mature crystal indicates a trend of decreasing sulfur and increasing nickel concentration towards the tip of the mature crystals. Following thorough investigation of these nanocrystals at different stages of their nucleation and growth by means of XRD, HR-SEM, HR-TEM, and Raman spectroscopy, we suggest possible kinetic mechanisms for the crystal formation and development. This work contributes to the understanding of growth mechanisms of dendritic structures with complex morphology.

Conducting polymers, mainly polyaniline (PANI) and polypyrrole (PPY) with positive charges bind to the negatively charged bacterial membrane to interfere with bacterial activities. After this initial electrostatic adherence, the conducting polymers might partially penetrate the bacterial membrane and interact with other intracellular biomolecules. Conducting polymers can form polymer composites with metal, metal oxides, and nanoscale carbon materials as a new class of antimicrobial agents with enhanced antimicrobial properties. The accumulation of elevated oxygen reactive species (ROS) from composites of polymers-metal nanoparticles has harmful effects and induces cell death. Among such ROS, the hydroxyl radical with one unpaired electron in the structure is most effective as it can oxidize any bacterial biomolecules, leading to cell death. Future endeavors should focus on the combination of conducting polymers and their composites with antibiotics, small peptides, and natural molecules with antimicrobial properties. Such arsenals with low cytotoxicity are expected to eradicate the ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.

Pt–Ni polyhedral nanoparticles (NPs) are extensively studied as electrocatalysts, mainly for oxygen reduction reaction (ORR), but they display a poor activity for the oxygen evolution reaction (OER). Here, ultralow platinum Pt@Ni@Pt core–bishell nanorods were designed (less than 1 wt % of Pt), synthesized, and characterized to yield bifunctional electrocatalysts with high efficiency toward ORR and OER in alkaline media. Ultralow platinum Pt@Ni@Pt core–bishell nanorods achieve an unprecedented (for a Pt-based catalyst) overpotential of 0.29 V at 10 mA cm–2 and current density of 162 mA μg–1Pt at 1.6 V (vs RHE) for the OER, while still maintaining a very decent value of 0.32 A mg–1Pt at 0.85 V for the ORR. These values outperform the standard Pt catalyst for the ORR and the Ni catalyst for the OER, using less than 1 wt % Pt. We describe the two-step synthesis of the Pt@Ni@Pt nanorods, demonstrating the …

Rechargeable Li metal batteries (LMBs) have attracted wide attention as promising candidates for the next generation of energy-storage systems. However, limited Coulombic efficiency and unregulated dendrite growth restrict its application. Here, we report a kind of electrolyte by introducing fluorinated aromatic diluents into high-concentration electrolytes (HCEs). Unlike other localized HCEs, the fluorinated aromatic diluents pairing with anions promote the formation of a homogeneous and robust solid–electrolyte interphase (SEI), which endows Li metal with an ultrahigh Coulombic efficiency of ∼99.8%. The Li||LiNi0.8Co0.1Mn0.1O2 battery holds a capacity retention of >80% over 260 cycles even with a thin Li anode (20 μm) and a high cathode loading (3.5 mAh cm–2). A 1.8 Ah Li||NMC811 pouch cell with a lean electrolyte delivers an energy density of 340 Wh kg–1 and a stable cycling life over 200 cycles. The …