Synergistic Electronic Interaction of Nitrogen Coordinated Fe-Sn Double-Atom Sites: An Efficient Electrocatalyst for Oxygen Reduction Reaction.

Double-atom site catalysts (DASs) have emerged as a recent trend in the oxygen reduction reaction (ORR), thereby modifying the intermediate adsorption energies and increasing the activity. However, the lack of an efficient dual atom site to improve activity and durability has limited these catalysts from widespread application. Herein, the nitrogen-coordinated iron and tin-based DASs (Fe-Sn-N/C) catalyst are synthesized for ORR.

Synthesis of Upper-Rim Sulfanylpropyl- and Methoxyphenylazo-Substituted Calix[4]arenes as Chromogenic Sensors for Hg and Ag Ions.

A series of calix[4]arenes with upper-rim sulfanylpropyl and -methoxyphenylazo groups (compounds -) were synthesized and found to be effective chromogenic sensors for selectively detecting Hg, Hg, and Ag ions among 18 screened metal perchlorates. In comparison to previously reported diallyl- and dithioacetoxypropyl-substituted calix[4]arenes (, , , , and ) and the newly synthesized compound , the distal (5,17)-disulfanylpropyl-substituted di--methoxyphenylazocalix[4]arene demonstrated superior performance with a limit of detection of 0.028 μM for Hg ions in a chloroform/methanol (v/v = 399/1) cosolvent.

Investigation on broadband emission of two-dimensional melamine lead iodide perovskite (2D-CHNPbI): An experimental and theoretical approach.

Novel two-dimensional melamine lead iodide perovskite (2D-CHNPbI) is synthesized to investigate its crystallinity, optical band gap and broadband emission properties and to make comparisons with 2D-CHNPbCl/2D-CHNPbBr perovskites. Both experimental and density functional theory (DFT) interrogations on 2D-CHNPbX (X = Cl, Br and I) are conducted. The crystal structure, morphology and percentile of Pb and halide elements are confirmed using scanning electron microscope (SEM), and energy dispersive spectrum (EDS), powder/single crystal X-ray diffraction (PXRD/SXRD), DFT and X-ray crystallography simulations.

Axial Chlorine Induced Electron Delocalization in Atomically Dispersed FeN4 Electrocatalyst for Oxygen Reduction Reaction with Improved Hydrogen Peroxide Tolerance.

Atomically dispersed iron sites on nitrogen-doped carbon (Fe-NC) are the most active Pt-group-metal-free catalysts for oxygen reduction reaction (ORR). However, due to oxidative corrosion and the Fenton reaction, Fe-NC catalysts are insufficiently active and stable. Herein, w e demonstrated that the axial Cl-modified Fe-NC (Cl-Fe-NC) electrocatalyst is active and stable for the ORR in acidic conditions with high H O tolerance.