Diketopyrrolopyrrole-based Donor-Acceptor Covalent Organic Frameworks for Iodine Capture.

The recovery of radioactive iodine from nuclear waste and contaminated water sources is a critical environmental concern, which poses significant technical challenges. Herein, the study has demonstrated that tuning the electronic properties of diketopyrrolopyrrole-based donor-acceptor covalent organic frameworks (COFs) enhances iodine trapping, improves charge transport, and strengthens iodine interactions - establishing a structure-property relationship. This tuning is achieved by synthesizing COFs with the diketopyrrolopyrrole-based linker 3,6-bis(4-(1,3-dioxolan-2-yl)phenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DKP) in combination with either the electron acceptor 4,4',4″-(1,3,5-triazine-2,4,6-triyl)trianiline (TTT-DKP) or the electron donor N,N-bis(4-aminophenyl)benzene-1,4-diamine (TAPA-DKP) linkers.

Improving Charge Transfer Kinetics of Ni Hydroxide Through Chromium: Efficient Production of Benzoic Acid at Ampere-Level Current Density.

Hybrid water electrolysis with the simultaneous generation of hydrogen and value-added chemicals enhances the viability of the water electrolysis process. A remarkably high current density of 1.4 A cm toward benzyl alcohol oxidation (BOR) at a low potential of 1.

Decoding the Hume-Rothery Rule in a Bifunctional Tetra-metallic Alloy for Alkaline Water Electrolysis.

The 90-year-old Hume-Rothery rule was adapted to design an outstanding bifunctional tetra-metallic alloy electrocatalyst for water electrolysis. Following the radius mismatch principles, Fe (131 pm) and Ni (124 pm) are selectively incorporated at the Pd (139 pm) site of MoPd nanosheets. Analogously, Cu (132 pm) alloys with only Pd, while Ag (145 pm) alloys with both Pd and Mo (154 pm).

The impact of ligand chain length on the HER performance of atomically precise Pt(SR) nanoclusters.

Atomically precise metal cluster-based electrocatalysts have been paid significant attention for an efficient hydrogen evolution reaction (HER). Herein, we have synthesized atomically precise Pt(SR) nanoclusters using 3-mercaptopropionic acid (MPA), 6-mercaptohexanoic acid (MHA), 8-mercaptooctanoic acid (MOA), and 11-mercaptoundecanoic acid (MUA) thiol ligands in aqueous media at room temperature to understand the impact of ligand chain length on the HER performance. The composition of Pt(SR) metal clusters was confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry.

High Ammonia Yield Rate from Dilute Nitrate Solutions Using a Cu(100)-Rich Foil: A Step Closer to Large-Scale Production.

The electrochemical reduction of nitrate (NO) ions to ammonia (NH) provides an alternative method to eliminate harmful NO pollutants in water as well as to produce highly valuable NH chemicals. The NH yield rate however is still limited to the μmol h cm range when dealing with dilute NO concentrations found in waste streams. Copper (Cu) has attracted much attention because of its unique ability to effectively convert NO to NH.

Covalent Organic Framework Catalyzed Amide Synthesis Directly from Alcohol Under Red Light Excitation.

The dehydrogenative coupling of alcohols and amines to form amide bonds is typically catalysed by homogeneous transition metal catalysts at high temperatures ranging from 130-140 °C. In our pursuit of an efficient and recyclable photocatalyst capable of conducting this transformation at room temperature, we report herein a COF-mediated dehydrogenative synthesis. The TTT-DHTD COF was strategically designed to incorporate a high density of functional units, specifically dithiophenedione, to trap photogenerated electrons and effectively facilitate hydrogen atom abstraction reactions.

Phenothiazine Embedded Dithiasmaragdyrins.

Two different types of novel phenothiazine-embedded dithiasmaragdyrins containing one phenothiazine ring, two thiophene rings and two pyrrole rings connected via three meso carbons and two direct bonds in the macrocyclic framework were synthesized over the sequence of synthetic steps starting with phenothiazine. Three examples of phenothiazine-embedded dithiasmaragdyrins were synthesized by condensing appropriate phenothiazine-based pentapyrrane with pentafluorobenzaldehyde and two examples of phenothiazine sulfone embedded dithiasmaragdyrins were synthesized by condensing phenothiazine-based diol with appropriate meso-aryl dipyrromethane under mild acid-catalysed conditions. 1D&2D NMR studies revealed that the thiophene rings adopted inverted orientation in phenothiazine sulfone embedded dithiasmaragdyrins whereas in phenothiazine-embedded dithiasmaragdyrins, the thiophene rings were in normal orientation.

Hydrogen Evolution in Neutral Media by Differential Intermediate Binding at Charge-Modulated Sites of a Bimetallic Alloy Electrocatalyst.

The energy barrier to dissociate neutral water has been lowered by the differential intermediate binding on the charge-modulated metal centers of CoMo sheets supported on Ni-foam (NF), where the overpotential for hydrogen evolution reaction (HER) in 1 M phosphate buffer solution (PBS) is only 50±9 mV at -10 mA cm. It has a turnover frequency (TOF) of 0.18 s, mass activity of 13.

Transition from Dion-Jacobson hybrid layered double perovskites to 1D perovskites for ultraviolet to visible photodetection.

New perovskite phases having diverse optoelectronic properties are the need of the hour. We present five variations of RAgM(iii)X, where R = NHCHNH (4N4) or NHCHNH (6N6); M(iii) = Bi or Sb; and X = Br or I, by tuning the composition of (4N4)AgBiBr, a structurally rich hybrid layered double perovskite (HLDP). (4N4)AgBiBr, (4N4)AgSbBr, and (6N6)AgBiBr crystallize as Dion-Jacobson (DJ) HLDPs, whereas 1D (6N6)SbBr, (4N4)-BiI and (4N4)-SbI have -connected chains by corner-shared octahedra.

Boosting photo-assisted efficient electrochemical CO reduction reaction on transition metal single-atom catalysts supported on the CN nanosheet.

CO reduction to value-added chemicals turns out to be a promising and efficient approach to resolve the increasing energy crisis and global warming. However, the catalytic efficiency of CO reduction reaction (CORR) to form C products (CO, HCOOH, CHOH, CH) needs to be quite efficient. Herein with the help of density functional theory, CORR towards C products was investigated on a transition metal (TM = Fe, Co, Ni) embedded CN framework.

Inverse 'intra-lattice' charge transfer in nickel-molybdenum dual electrocatalysts regulated by under-coordinating the molybdenum center.

The prevalence of intermetallic charge transfer is a marvel for fine-tuning the electronic structure of active centers in electrocatalysts. Although Pauling electronegativity is the primary deciding factor for the direction of charge transfer, we report an unorthodox intra-lattice 'inverse' charge transfer from Mo to Ni in two systems, NiMo alloy electrodeposited on Cu nanowires and NiMo-hydroxide (Ni : Mo = 5 : 1) on Ni foam. The inverse charge transfer deciphered by X-ray absorption fine structure studies and X-ray photoelectron spectroscopy has been understood by the Bader charge and projected density of state analyses.

Lattice Mismatch Guided Nickel-Indium Heterogeneous Alloy Electrocatalysts for Promoting the Alkaline Hydrogen Evolution.

The immiscibility of crystallographic facets in multi-metallic catalysts plays a key role in driving the green H production by water electrolysis. The lattice mismatch between tetragonal In and face-centered cubic (fcc) Ni is 14.9 % but the mismatch with hexagonal close-packed (hcp) Ni is 49.

Computational Insight into TM-N Embedded Graphene Bifunctional Electrocatalysts for Oxygen Evolution and Reduction Reactions.

Due to the energy crisis, development of bifunctional electrocatalysts for both oxygen evolution and reduction reactions is highly demanding. In this study, we have systematically investigated the bifunctional activity of metal (Co/Rh/Ir) and N co-doped graphene systems with varying N-dopant concentrations (TM-N @G, = 0, 2, 4) using first-principles calculations. Charge transfer from the metal sites to the adsorbed intermediates and the adsorption free energy of the intermediates play important roles to help understand the potential-determining step and overpotential values for oxygen evolution reaction (OER)/oxygen reduction reaction (ORR).

Urea Production on Metal-Free Dual Silicon Doped C N Nanosheet Under Ambient Conditions by Electrocatalysis: A First Principles Study.

The development of cheap, eco-friendly electrocatalysts for urea synthesis which avoids the traditional nitrogen reduction to form ammonia, is very important to meet our growing demand for urea. Herein, based on density functional theory, we propose a novel electrocatalyst (dual Si doped C N nanosheet) composed of totally environmentally benign non-metal earth abundant elements, which is able to adsorb N and CO together. Reduction of CO to CO happens, which is then inserted into activated N-N bond, and it produces *N(CO)N intermediate, which is the crucial step for urea formation.

Regioselective ring-opening of epoxides towards Markovnikov alcohols: a metal-free catalytic approach using abnormal N-heterocyclic carbene.

Herein we report the first metal-free regioselective Markovnikov ring-opening of epoxides (selectivity up to 99%) using an abnormal N-heterocyclic carbene (aNHC) to yield secondary alcohols. DFT calculations and X-ray crystallography suggest that the Markovnikov selectivity originates from the high nucleophilicity and steric factors associated with the aNHC.

Anchoring boron on a covalent organic framework as an efficient single atom metal-free photo-electrocatalyst for nitrogen fixation: a first-principles analysis.

The production of ammonia in a sustainable cost-effective manner and ambient conditions is a very challenging task. Photo-/electrocatalytic nitrogen reduction (NRR) is a convenient way to produce NH for industrial applications. In this work, anchoring B atoms in Tp-bpy-COF is shown to effectively reduce N to NH.