Publications

The production of ammonia (NH₃) in the industrial scale basically relies on the traditional technology of Haber-Bosch, which is operated under harsh conditions with high energy consumption and a huge number of greenhouse gas emissions. Electrochemical N₂ reduction reaction (NRR) is a promising route for artificial N₂-to-NH₃ fixation with less energy consumption. However, an effective electrocatalyst, as a prerequisite of the NRR, is of significance. Here, we report that a spinel LiMn₂O₄ nanofiber acts as a noble-metal-free electrocatalyst for NH₃ synthesis with excellent performance under ambient conditions. The electrocatalyst, which was tested in 0.1 M HCl, has an excellent Faradaic efficiency of 7.44% and a NH₃ yield of 15.83 μg h^-1 mg_cat.^-1 at -0.50 V versus reversible hydrogen electrode. Moreover, it also possesses excellent electrochemical and structure stability.

Electrochemical N2-to-NH3 fixation under ambient conditions is emerging as a promising alternative to the energy-intensive and CO2-emitting Haber-Bosch process. However, this process involves difficulty in N2 activation, underlining the demand of electrocatalysts for the N2 reduction reaction (NRR). In this work, cubic sub-micron SnO2 particles on carbon cloth (SnO2/CC) are proposed as an efficient NRR electrocatalyst for ambient N2 conversion to NH3 with excellent selectivity. Electrochemical tests reveal that SnO2/CC attains a large NH3 yield of 1.47 × 10-10 mol s-1 cm-2 at -0.8 V vs. reversible hydrogen electrode (RHE) and a high Faradaic efficiency of 2.17% at -0.7 V vs. RHE in 0.1 M Na2SO4, outperforming most reported aqueous-based NRR electrocatalysts. Notably, it also shows strong electrochemical stability.

Background: Cephalosporins are cornerstone β-lactam antibiotics arranged into five generations that progressively expand gram-negative activity while preserving gram-positive coverage across common and severe infections.Aim: To synthesize practice-oriented guidance on spectrum, mechanisms, pharmacokinetics, indications, safety, contraindications, monitoring, and toxicity.Methods: Narrative review of the supplied article integrating generational profiles, cefiderocol approvals, population-specific dosing, adverse effects, and stewardship themes.Results: First generation targets staphylococci/streptococci; second adds respiratory gram-negatives and anaerobes; third broadens Enterobacteriaceae with CNS penetration (ceftazidime provides antipseudomonal activity); fourth-generation cefepime adds β-lactamase stability and antipseudomonal activity; fifth-generation ceftaroline uniquely covers MRSA. Cefiderocol, a siderophore cephalosporin, is FDA-approved for complicated UTI and ventilator-associated pneumonia due to resistant gram-negative bacilli. Safety issues include hypersensitivity, drug-induced immune hemolytic anemia, N-methyl-thiotetrazole–associated hypoprothrombinemia and disulfiram-like reactions, and antibiotic-associated Clostridioides difficile colitis. Contraindications include cephalosporin allergy, anaphylaxis to β-lactams, and neonatal ceftriaxone in hyperbilirubinemia or with calcium. Monitoring focuses on renal function, PT/INR, and hemolysis labs; cefepime neurotoxicity is the hallmark of overdose, and careful dose adjustment in renal impairment is essential.Conclusion: Cephalosporins remain versatile and effective; optimal outcomes require tailored selection and stewardship, while cefiderocol extends options against carbapenem-resistant gram-negatives

Abstract Renewable‐electricity‐driven N 2 reduction is an attractive approach for ambient NH 3 synthesis, but active electrocatalysts are needed to enable the N 2 reduction reaction. Monolithic electrodes with active components anchored on conductive supports provide many advantages like structural stability, large surface area, and low electrical resistance. Here, a novel “oxidation‐etching” strategy is proposed to carve the surface of Cu foam into structures of particles, cubes, and sheets for N 2 reduction electrocatalysis. The optimal catalyst achieves a Faradic efficiency as high as 18% at −0.35 V vs reversible hydrogen electrode (RHE) and a large NH 3 yield of 2.45 × 10 −10 mol s −1 cm −1 at −0.40 V vs RHE in 0.1 M HCl. Notably, it also shows superior long‐term electrochemical durability, with the preservation of electro‐activity for at least 20 hours. image

Abstract In the present report, the generation of Tantalum oxyfluoride and oxynitride upon ammonolysis of the gel obtained from modified tantalum-alkoxo complexes is reported. To the best of our knowledge, this is first report of the formation of tantalum oxyfluoride thin films via ammonolysis of the β-diketone modified tantalum-alkoxo complex [Ta(OEt) 4 (CF 3 COCH 2 COCH 3 )] m . The integration of nitrogen and fluorine in lattice sites of metal oxides leads to significant reduction in the band gap, resulting in their activation under visible light. Moreover, in this report the effect of the modified alkoxide precursors and ammonolysis on the photo-physical properties of Ta 2 O 5 thin films have also been investigated and compared with the results obtained from films fabricated from unmodified tantalum (V) ethoxide. 1 H NMR, 13 C NMR and elemental analyses confirmed successful modification of tantalum (V) ethoxide to [Ta(OCH 2 CH 3 ) 4 (CH 3 COCHClCOCH 3 )] m ( 1 ), [Ta(OCH 2 CH 3 ) 4 (CF 3 COCH 2 COCH 3 ] m ( 2 ) and [Ta(OCH 2 CH 3 ) 4 (CH 3 COC(CH 3 ) 2 COCH 3 ))] m ( 3 ). The fabrication of Ta 2 O 5 thin films involved the spin casting of the gels of modified tantalum alkoxo complexes (processed by sol-gel method) on to glass substrate. X-ray photoelectron spectroscopy results show that nitrogen was incorporated into the ammonolyzed films fabricated from complex precursors ( 1 ) and ( 3 ), while the presence of fluorine as tantalum oxyfluoride was confirmed in the ammonolyzed film fabricated from complex ( 2 ) precursor. The optical characterization insinuate band gap narrowing from 3.55 eV for undoped film prepared from tantalum (V) ethoxide to 3.47 eV for undoped film prepared from [Ta(OEt) 4 (CF 3 COCH 2 COCH 3 )] m and 3.05 eV for ammonolyzed film obtained from [Ta(OEt) 4 (CF 3 COCH 2 COCH 3 )] m precursor. Furthermore, enhanced photocatalytic efficiency of the films is demonstrated by degradation of methylene blue dye.

Abstract In this work, electrochemically-driven Kraton/graphene oxide/Ag/polyaniline (Kraton/GO/Ag/Pani) polymer composite based ionic polymer metal composite (IPMC) was fabricated as a soft actuator. Silver nanopowder with polyaniline coating used as an electrode material is a novel approach in the fabrication of IPMC, which gives new opportunities for development of the electrode on ionic polymer actuator surfaces directly without electroless plating of Pt or Au metal. The Kraton/GO/Ag/Pani membrane showed much higher water-uptake (WU), ion exchange capacity (IEC), proton conductivity than those of several reported IPMC membranes. The enhanced actuation performance indicates that the Kraton/GO/Ag/Pani is a better alternative to the highly expensive commercialized IPMC actuator.

The formation of hydrocarbon species during the methanol to olefins (MTO) reaction over zeolite H-SSZ-13 has been systematically studied at reaction temperatures between 573 and 723 K with a combination of operando UV–vis spectroscopy and online gas chromatography. It was found that the applied reaction temperature influences the rate and nature of coke formation as well as the catalyst stability. Correlation between all hydrocarbon species formed inside the catalyst pores with the activity and deactivation of H-SSZ-13 zeolite material was established. By using a multivariate analysis, we found that the nature of the active and deactivating species varies with the reaction temperature. The majority of active hydrocarbon pool species at low reaction temperatures (i.e., 573–598 K) are methylated benzene carbocations, while at high reaction temperatures (i.e., 623–723 K) methylated naphthalene carbocations become dominant. At low reaction temperatures the deactivation occurs because of the pore filling with methylated naphthalene carbocations. In contrast, at higher reaction temperatures the formation of phenanthrene, pyrene carbocations, and highly conjugated polyaromatics during the deactivation increases. This suggests that the formation of highly conjugated polyaromatics on the external surface can play a role in the deactivation of the material by pore blockage.

Ruthenium (Ru)-modified (up to 1 wt %) tungsten trioxide (WO3) samples were synthesized and characterized by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopy, and Raman spectroscopy. Ru was found to form hexagonal clusters on {111} planes of the underlying WO3 crystals with similar arrangement as is found in metal Ru. XPS revealed that the valence state of ruthenium corresponds to the oxidized state. Results indicate that bonding between Ru and oxygen of the crystal surfaces is a key factor for the cluster formation. No evidence for a crystalline ruthenium oxide or metal phase formation was found instead Ru atoms were bonded on oxygen on the WO3 {111} planes.

It is highly desirable to develop efficient and durable oxygen evolution reaction (OER) electrocatalysts. Herein, we report the in situ development of an Fe-(tetracyanoquinodimethane)₂ nanowire array on Fe foil (Fe(TCNQ)₂/Fe) via a solution immersion method. As a non-noble-metal OER electrocatalyst, such Fe(TCNQ)₂/Fe needs an overpotential of only 340 mV to drive a geometrical catalytic current density of 10 mA cm^-2 in 1.0 M KOH. Notably, it also shows strong long-term electrochemical durability capable of maintaining its catalytic activity for at least 110 h.

This review summarizes recent advances in developing sputtered nanomaterials as catalysts for energy electrocatalysis. In-depth insights into architecture/compositional design, synthesis, mechanism, and performance are provided.