Unfortunately, the practical applications of Li-O2 batteries are impeded by poor rechargeability. Here, for the first time we show that superoxide radicals generated at the cathode during discharge react with carbon that contains activated double bonds or aromatics to form epoxy groups and carbonates, which limits the rechargeability of Li-O2 cells. Carbon materials with a low amount of functional groups and defects demonstrate better stability thus keeping the carbon will-o'-the-wisp lit for lithium-air batteries.

We found for the first time a new origin of selection of perovskite crystallization pathways from DMF solutions containing MAI and PbI 2 to present here a comprehensive study of a full set of essential intermediate phases determining the perovskite's morphology. For all three discovered structurally different intermediate phases forming at a given precursor ratio, we refined their crystal structures by synchrotron X-ray radiation and investigated dynamics and phase assemblage in the course of decomposition. As a result, we revealed a clear correlation between the composition of the intermediate phases, peculiarities of their crystal structure, and the morphology of the final perovskite films. Using the DFT method we calculated formation enthalpies of these intermediate phases and explained the preferential precipitation of DMSO-adduct rather than DMF-adduct in an antisolvent approach. This finding opens up a possibility of design-on-demand of perovskite materials using simple soft chemistry approaches.

Gold degradation under UV-light through local formation of a reactive polyiodide melt and its rapid reaction with gold resulting in the MA2Au2I6 phase.

Transition metal dichalcogenide materials have recently been shown to exhibit a variety of intriguing optical and electronic phenomena. Focusing on the optical properties of semiconducting WS2 nanotubes, we show here that these nanostructures exhibit strong light-matter interaction and form exciton-polaritons. Namely, these nanotubes act as quasi 1-D polaritonic nano-systems and sustain both excitonic features and cavity modes in the visible-near infrared range. This ability to confine light to subwavelength dimensions under ambient conditions is induced by the high refractive index of tungsten disulfide. Using "finite-difference time-domain" (FDTD) simulations we investigate the interactions between the excitons and the cavity mode and their effect on the extinction spectrum of these nanostructures. The results of FDTD simulations agree well with the experimental findings as well as with a phenomenological coupled oscillator model which suggests a high Rabi splitting of ∼280 meV. These findings open up possibilities for developing new concepts in nanotube-based photonic devices.

The chemical origin of solvents typically used for preparation of hybrid lead halide perovskitesdimethyl sulfoxide (DMSO), dimethylformamide (DMF), and γ-butyrolactone (GBL)strongly influences the process of perovskite crystallization because of the formation of intermediate adducts with different structures and morphology. The composition and crystal structures of the adducts depend on the coordination and binding ability of the solvents and the ratio of the precursors. New adducts of perovskite and GBL with either an unusual cluster structure, (MA) 8 (GBL) x [Pb 18 I 44 ], or an adduct, (MA) 2 (GBL) 2 Pb 3 I 8 , similar to those observed for DMF and DMSO are described for the first time. Complex equilibriums between chemical species existing in perovskite solutions are revealed by Raman spectroscopy. As a result, new features of the perovskite crystallization through intermediate adduct phases are discussed, and effective perovskite deposition pathways are suggested. ■ EXPERIMENTAL SECTIONMaterials and Methods. Methylammonium iodide (CH 3 NH 3 I = MAI, Dyesol), formamidinium iodide (CH 5 N 2 I = FAI, ≥98%, Dyesol), lead iodide (PbI 2 , 99%, Sigma-Aldrich), dimethyl sulfoxide

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Selective study of the electron transport chain components in living mitochondria is essential for fundamental biophysical research and for the development of new medical diagnostic methods. However, many important details of inter-and intramembrane mitochondrial processes have remained in shadow due to the lack of non-invasive techniques. Here we suggest a novel label-free approach based on the surface-enhanced Raman spectroscopy (SERS) to monitor the redox state and conformation of cytochrome c in the electron transport chain in living mitochondria. We demonstrate that SERS spectra of living mitochondria placed on hierarchically structured silver-ring substrates provide exclusive information about cytochrome c behavior under modulation of inner mitochondrial membrane potential, proton gradient and the activity of ATP-synthetase. Mathematical simulation explains the observed enhancement of Raman scattering due to high concentration of electric nearfield and large contact area between mitochondria and nanostructured surfaces.Mitochondria are organelles of fundamental importance for cellular energy production, metabolic regulation, aging and cell survival under stress [1][2][3] . Normal function of mitochondria and their pathological changes, including production of reactive oxygen species (ROS), are heavily dependent on the redox state of the electron transport chain (ETC) cytochromes and cytochrome c in particular 4,5 . At present, most of the studies of isolated mitochondria and mitochondria in cells are performed by fluorescent microscopy, absorption spectroscopy and measurements of O 2 consumption 3,[6][7][8] . The fluorescent microscopy with small fluorescent dyes (rhodamin and MitoTracker-family, etc.) or fluorescent proteins (GFP, YFP, RFP) can provide general information about changes in the potential of the inner mitochondrial membrane (Δ Φ ), the mitochondrial volume, and the co-localization of certain mitochondrial components with a molecule of interest

Crystal structure, thermal behaviour and phase transitions of formamidinium iodide were studied by DTG, DSC, powder diffraction and X-ray crystallography.