Xun Feng

1. Triclopyr, chemical name 2-((3,5,6-trichloropyridin-2-yl)oxy)acetic acid (3,5,6-Htcpa) [1], is a kind of biocative organic molecule and is generally used as a pesticide, herbicide, and plant gro...

Three ligands with different 6-substituent based on 5-bromo-pyridine-2-carboxylic acid (5-Br-Hpyc) skeleton, namely 3-Br-pyridine-2,6-dicarboxylic acid (3-Br-H2pydc), 5-bromo-6-methyl-pyridine-2-carboxylic acid (5-Br-6-Me-Hpyc) and itself, were used to react with CuCl2·2H2O under solvothermal conditions and generated five diverse copper(II) compounds [Cu(3-Br-pydc)(H2O)3] (Cu1), [Cu(5-Br-6-Me-pyc)2(H2O)·2H2O] (Cu2), [Cu(5-Br-pyc)2]n (Cu3), [Cu(5-Br-pyc)2(H2O)] (Cu4) and [Cu(5-Br-pyc)2(H2O)2] (Cu5), of which the latter three were the products of one-pot crystallization. Structural analysis indicated that Cu1, Cu2, Cu4, Cu5 were all monomuclear complexes and the corresponding anion among them were tridentate (Cu1) or bidentate chelate ligand (Cu2, Cu4, Cu5). While Cu3 was a 1D linear polymer and 5-Br-pyc anion in it adopted tridentate chelate bridging μ2 linking fashion. The coordination geometry of Cu(II) center for them was octahedron (Cu1, Cu3, Cu5) or square pyramid (Cu2, Cu4). Various non-covalent interactions of hydrogen bonds (O–H···O/C–H···O/C–H···Br), halogen bonds (Br···Br/Br···O), Br···π interaction (Br···C) and/or π···π staking played an important part in their 3D crystal packing, which have been confirmed by the careful Hirshfeld surface analysis. After the deeply structural comparison and synthesis condition exploration, it can be proposed that the space steric hindrance of the large -Br substituent and the different 6-substituent (-COOH, -Me, -H) on ligand may be the decisive factors for producing the finally structural types. Besides, the magnetic characterizations showed that between the neighbouring Cu(II) ions, there were weak ferromagnetic exchange in Cu1 but antiferromagnetic coupling in Cu2, respectively.

Ruthenium metal has been widely utilized as an efficient catalyst for hydrogen production electrocatalytic water splitting. However, its high cost and low atomic utilization efficiency are regarded as significant limitations for practical applications. In this study, Ru nanoparticles with sizes ranging from 2 to 10 nm were grown in situ onto the modified surface of sepiolite, a cheap mineral with limited electrical conductivity, via a low-cost synthetic strategy under mild conditions. The novelly synthesized catalyst shows a specific surface area of 422.1 m2/g with a pore volume of 0.213 cm3/g, and the multi-level pore structure of carbonized modified sepiolite is maintained. XPS and FTIR results indicate that abundant C-O-Ru functional groups. The synthesized composite exhibits excellent HER performance in acidic electrolytes, with an overpotential of 38 mV (a 10 mA/cm2 current density), even lower than commercial platinum-carbon catalysts (39 mV). And stability of the catalyst is maintained after an 18-hour cycle, with a high-frequency region of the Nyquist diagram and minimal impedance arc diameter. Theoretical calculations also demonstrate that the synthesized catalyst exhibits considerable water adsorption capability (-0.925eV) while maintaining a near-optimal ΔGH* value (-0.14eV), which is favor of Volmer step and efficient hydrogen desorption.

Partial alkali-leaching of Al–Fe–Si alloy can generate a highly active and stable Fe-based catalyst for CO ₂ hydrogenation to light olefins.

Smartphone-assisted paper strip platform with Eu-NCP-PZDC ratiometric probe for rapid (2 min) visual detection of PO ₄ ³⁻ in milk, achieving a low LOD (48 nM) and wide linear range (0–320 µM) via RGB analysis.

A highly promising electrocatalyst has been designed and prepared for the hydrogen evolution reaction (HER). This involves incorporating well-dispersed Ir nanoparticles into a cobalt-based metal-organic framework known as Co-BPDC [Co(bpdc)(H₂O)₂, BPDC: 4,4'-biphenyldicarboxylic acid]. Ir@Co-BPDC demonstrates exceptional HER activity in alkaline media, surpassing both commercial Pt/C and recent noble-metal catalysts. Theoretical results indicate that electron redistribution, induced by interfacial bonds, optimizes the adsorption energy of water and hydrogen, thereby enhancing our understanding of the superior properties of Ir@Co-BPDC for HER.