Stabilizing the black phase of cesium lead halide inorganic perovskite for efficient solar cells

Inorganic perovskite cesium lead halide is extensively studied because of its potential in improving the thermal stability of perovskite materials. However, the tolerance factor of this type of perovskite is near the critical value, which leads to phase instability. The optoelectronic active black phases(α, β, and γ phases of CsPbI_3) are metastable at room temperature, which can be easily transferred into an optoelectronic inactive yellow phase(δ-CsPbI_3). This review highlights recent progress in stabilizing the black phase for efficient and stable perovskite solar cells.     

A high yield method for the direct amidation of long-chain fatty acids

The amidation of long-chain fatty acids is the key step for preparing surfactants with excellent interfacial activity. Gas chromatography–mass spectrometry was employed to detect the reactants and products in the direct amidation reactions. The conversion and the concentration of the amides in the reaction process were also investigated to determine the best catalyst, the reaction rate constants, and activation energy. It was identified that the amidation reaction of the long-chain phenyl fatty acid was a zero-order reaction and 3,4,5-trifluorophenylboronic acid was the most effective catalyst by which the activation energy reduced to 55.79 kJ/mol from 95.44 kJ/mol. The method can be applied to other long-chain fatty acids, saturated or unsatureated. The turning-over-temperature was 156°C, over which high yields can be achieved without any catalyst. These provide a reference for the preparation of long-chain fatty acid amides.     

Anion Modulation of Pt-Group Metals and Electrocatalysis Applications

Pt-group metal (PGM) electrocatalysts with unique electronic structures and irreplaceable comprehensive properties play crucial roles in electrocatalysis. Anion engineering can create a series of PGM compounds (such as RuP₂, IrP₂, PtP₂, RuB₂, Ru₂B₃, RuS₂, etc.) that provide a promising prospect for improving the electrocatalytic performance and use of Pt-group noble metals. This review seeks the electrochemical activity origin of anion-modulated PGM compounds, and systematically analyzes and summarizes their synthetic strategies and energy-relevant applications in electrocatalysis. Orientation towards the sustainable development of nonfossil resources has stimulated a blossoming interest in the design of advanced electrocatalysts for clean energy conversion. The anion-modulated strategy for Pt-group metals (PGMs) by means of anion engineering possesses high flexibility to regulate the electronic structure, providing a promising prospect for constructing electrocatalysts with superior activity and stability to satisfy a future green electrochemical energy conversion system. Based on the previous work of our group and others, this review summarizes the up-to-date progress on anion-modulated PGM compounds (such as RuP₂, IrP₂, PtP₂, RuB₂, Ru₂B₃, RuS₂, etc.) in energy-related electrocatalysis from the origin of their activity and synthetic strategies to electrochemical applications including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), N₂ reduction reaction (NRR), and CO₂ reduction reaction (CO₂RR). At the end, the key problems, countermeasures and future development orientations of anion-modulated PGM compounds toward electrocatalytic applications are proposed.     

Effects of size and location of distal tear on hemodynamics and wave propagation in type B aortic dissection

Applied Mathematics and Mechanics - The type B aortic dissection (TBAD) is a perilous disease with high morbidity and mortality rates. The hemodynamics of TBAD in different scenarios has been...     

Metal-directed thiophene-carboxylate-based nickel(II) complexes as multifunctional electrochemical and fluorescent sensors for detecting different analytes

Transition Metal Chemistry - To investigate the effect of the sites of S-atoms in thiophene carboxylates on the structures of coordination polymers, two thiophene-mono-carboxylic acids...     

Unconventional Approaches to Hydrogen Sorption Reactions: Non-Thermal and Non-Straightforward Thermally Driven Methods

In the last decades, a broad family of hydrides have attracted attention as prospective hydrogen storage materials of very high gravimetric and volumetric capacity, fast H₂-sorption kinetics, environmental friendliness and economical affordability. However, constraints due to their high activation energies of the different H₂-sorption steps and the Gibbs energy of their reaction with H₂ has led to the need of high thermal energy to drive H₂ uptake and release. High heat leads to significant degradation effects (recrystallization, phase segregation, nanoparticles agglomeration…) of the hydrides. In this context, this short review aims to summarize alternative non-thermal methods and non-straightforward thermally driven methods to overcome the previous constraints. The phenomenology lying behind these methods, i. e. tribological activation, sonication, and electromagnetic radiation, and the effect of these processes on hydrogen sorption properties of hydrides are described. These non-usual approaches could boost the capability of the next generation of solid-hydride materials for hydrogen conversion in energy sector, in mobile devices and as hydrogen reservoirs.     

Crystal growth and luminescence properties of CuI single crystals

Recently, much attention has been attached to the material of cuprous iodide (CuI) single crystals. In this paper, a detailed study of the variation in the nucleation density and the growth of CuI crystals in silica gel as a function of the concentration of feed solution, pH of gel, gel aging time, growth temperature and volume of the feed solution is presented. The optimum conditions for growth of large size CuI single crystals in gel are: pH 5, concentration of complex 0.244 M, gel aging 72 h, temperature 45 °C. A simple procedure for increasing the size of the crystals is adopted and the CuI single crystal with the size of 4 mm³ is obtained. Also, the photoluminescence (PL) spectrum of as-grown CuI crystals in silica gel is evaluated by comparing its PL spectra with that of CuI crystals grown by solvent evaporation method. The results could provide a useful clue to further improve the properties of CuI single crystals.