Dalton Transactions最新文献

Aqueous zinc–sodium hybrid batteries with a Prussian blue cathode have been extensively studied in recent years. However, less research has been conducted on low-cost ferric ferricyanide (FeFe(CN)₆) cathode materials. Considering that both Zn²⁺ and Na⁺ can be reversibly embedded in FeFe(CN)₆ crystals, here we focus on mixed electrolytes with different concentrations of ZnSO₄ and Na₂SO₄ in deionized water to explore the preference of FeFe(CN)₆ towards Zn²⁺ and Na⁺. As a result, by using 0.1 M ZnSO₄ + 1 M Na₂SO₄ electrolyte, a superior battery performance is obtained, which reveals that the co-function of Zn²⁺ and Na⁺ in this electrolyte promotes Zn//FeFe(CN)₆ cells to exert a superior specific capacity. In this work, FeFe(CN)₆ is synthesized by a co-precipitation method and is analyzed by XRD, SEM, etc., and then used as the cathode material in Zn–Na hybrid batteries. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests show that FeFe(CN)₆ in 0.1 M ZnSO₄ + 1 M Na₂SO₄ electrolyte delivers the highest discharge/charge capacities of 165.2/165.9 mA h g⁻¹ (theoretical specific capacity: 212.2 mA h g⁻¹) at a 0.1 C current density, with good capacity retention of 84% after 200 cycles at 15 C, outperforming many of the reported Zn–Na hybrid cells.

A diamine-bis(phenolate) chromium(III) complex, CrOH[L] ([L] = dimethylaminoethylamino-N,N-bis(2-methylene-4,6-tert-butylphenolate)), 2, in the presence of tetrabutylammonium hydroxide effectively copolymerizes CO₂ and cyclohexene oxide (CHO) into a polycarbonate diol. The resultant low molar mass (6.3 kg mol⁻¹) diol is used to initiate ring-opening polymerization of rac-lactide with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) giving ABA-type block copolymers with good molar mass control through varying rac-LA-to-diol loadings and with narrow dispersities. As the degree of rac-LA incorporation increases, the glass transition temperatures (T_g) are found to decrease, whereas decomposition temperatures (T_d) increase. (Diphenylphosphonimido)triphenylphosphorane (Ph₂P(O)NPPh₃) was used as a neutral nucleophilic cocatalyst with 2, giving phosphorus-containing polycarbonates with an M_n value of 28.5 kg mol⁻¹, a dispersity of 1.13, a T_g value of 110 °C and a T_d value of over 300 °C. A related Cr(III) complex (4) having a methoxyethyl pendent group rather than a dimethylaminoethyl group was structurally characterized as a hydroxide-bridged dimer.

As a non-noble metal electrocatalyst for the oxygen evolution reaction (OER), the binary NiFe layer double hydroxide (LDH) is expected to replace Ru-based and Ir-based anode materials for water decomposition. To attain threshold current density, nevertheless, a somewhat significant overpotential is still needed. In this work, layered double hydroxides of NiFe LDH are doped with V to form the terpolymer NiFeV LDH, which greatly increases the intrinsic activity of NiFe LDH and improves OER performance. This process is a straightforward and quick one-step electrodeposition process. Notably, NiFeV/NF has a low overpotential (218 mV at 10 mA cm⁻²) and faster kinetics (Tafel slope of 31 mV dec⁻¹) as well as excellent durability and stability in 1 M KOH solution. In addition, the OER performance of the catalyst prepared in this work is better than that of a non-valuable metal catalyst that was recently reported. The V-doped NiFe LDH layered double hydroxides and the investigation of electrodeposition electrocatalytic methods in this work offer a fresh opportunity for the advancement of electrochemical technology.

In this paper, a new high-pressure (HP) polymorph of the otherwise known oxyfluoride K₂MoO₂F₄ is presented. The crystal structure was determined by use of single-crystal X-ray diffractometry and its features are described in detail herein. HP-K₂MoO₂F₄ crystallizes in the monoclinic space group C2/m (no. 12) with the cell parameters a = 13.8579(5), b = 5.8109(2), c = 6.9442(3) Å, β = 90.36(1)°, V = 559.18(4) ų, and Z = 4 at T = 301(2) K. Bond valence (BV) and charge distribution (CHARDI) calculations were carried out to support the assignment of oxygen and fluorine to the various anion positions and Madelung part of lattice energy (MAPLE) calculations were used to validate the structure model. Infrared spectroscopy provided further information on the structure and water content of the inseparable side phase.

A discrete liphophilic organotelluroxane macrocycle has been found to catalyse the hydrogen evolution reaction (HER) by proton reduction efficiently. The macrocycle is synthesized via chloride abstraction from bis(p-methoxyphenyl) tellurium dichloride (p-MeOC₆H₅)₂TeCl₂ (1) by silver salts AgMX₄ (MX₄ = BF₄⁻, and ClO₄⁻) resulting in in situ generated di-cationic tetraorganoditelluroxane units; two such units are held together by two weak anions μ₂-MX₄, bridging to form 12-membered di-cationic macrocycles [((p-MeO-C₆H₄)₂Te)₂(μ-O)(μ₂-F₂BF₂)₂]²⁺ (2) and [((p-MeO-C₆H₄)₂Te)₂(μ-O)(μ₂-O₂ClO₂)₂]²⁺ (3) stabilized via Te–(μ₂-BF₄/ClO₄), with secondary interactions. The charge is balanced by the presence of two more anions, one above and another below the plane of the macrocycle. Similar reaction at higher temperatures leads to the formation of telluronium salts R₃TeX [X = BF₄⁻ (4), ClO₄⁻ (5)] as a major product. The BF₄⁻ anion containing macrocycle and telluronium salt were monitored using ¹⁹F NMR. HRMS confirmed the structural stability of all the compounds in the solution state. The organotelluroxane macrocycle 2 has been found to act as an efficient electrocatalyst for proton reduction in an organic medium in the presence of p-toluene sulfonic acid as a protic source.

Herein, we report that Pd nanoparticles (NPs) anchored on graphitic nitride carbon (Pd/g-C₃N₄) catalysts with various Pd contents (1.55 wt%, 0.14 wt%, 0.04 wt%) are successfully prepared via a simple NaBH₄ reduction method, exhibiting excellent catalytic activity and selectivity toward 4-aminophenol (4-AP) in 4-nitrophenol (4-NP) selective hydrogenation. 4-NP is completely converted to 4-AP (yield ∼ 100%) under quite moderate reaction conditions (40 °C, 2.0 MPa H₂ and 5 min) over the 1.55 wt% Pd/g-C₃N₄ catalyst, with a high reaction rate r = 134.4 mol_4-NP mol_Pd⁻¹ min⁻¹. The excellent catalytic performance can be attributed to the following reasons: (1) a higher ratio of Pd(0)/Pdⁿ⁺ provides much more exposed active sites for the potential adsorption and activation of the reactants, which is beneficial for increasing the reaction rate and catalytic activity; (2) Pd NPs are highly dispersed on g-C₃N₄ due to the strong interaction of Pd–N or Pd–C; (3) the interfacial synergism effect between Pd NPs and g-C₃N₄ enables the effective adsorption and activation of H₂ (4-NP) at Pd (g-C₃N₄), promoting the catalytic hydrogenation of 4-NP and improving their catalytic properties. In addition, this catalyst has superior reusability.

Modulation of the octahedral crystal field environment of Cr³⁺ is an effective approach to achieve tunable emission. Here, we prepared a series of broadband MP₃O₉:Cr³⁺ (M = Al, Ga, In) near-infrared (NIR) phosphors, and cubic AlP₃O₉:Cr³⁺ (APO-c:Cr³⁺) and monoclinic AlP₃O₉:Cr³⁺ (APO-m:Cr³⁺) phosphors were prepared by controlling the synthesis temperature. The emission wavelength was tuned from 787 nm for APO-c:Cr³⁺ to 894 nm for monoclinic InP₃O₉:Cr³⁺ (IPO:Cr³⁺) by regulating the M ion and reducing the crystal field intensity. Excitingly, the MP₃O₉:Cr³⁺ (M = Al, Ga, In) family shows excellent thermal stability; the emission intensity of APO-c:Cr³⁺, APO-m:Cr³⁺ and monoclinic GaP₃O₉:Cr³⁺ (GPO:Cr³⁺) can still maintain 95.6%, 86% and 86% of that at room temperature when heating to 423 K, respectively. An NIR LED device was prepared by incorporating GPO:Cr³⁺ and a blue light LED, demonstrating the potential application in night vision and non-destructive testing.

The global health crisis of bacterial resistance to antibiotics requires innovative antibacterial strategies. One promising solution is the exploitation of multifunctional nanoplatforms based on non-resistant antibacterial mechanisms. This work reports a novel Fe₃O₄@Au/polydopamine (PDA) nanodurian with excellent photothermal-magnetomechanic synergistic antibacterial effects. The one-step formed Au/PDA hybrid shell provides good photothermal properties and spiky surfaces for enhanced magnetomechanic effects. Upon near-infrared (NIR) irradiation, the Fe₃O₄@Au/PDA nanodurian (200 μg mL⁻¹) achieved nearly 100% antibacterial effect against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The efficiency of photothermal antimicrobial activity was further enhanced by the application of a rotating magnetic field (RMF), with the sterilization efficiency being increased by up to more than a half compared to the action alone. Interestingly, the size of the nanodurian has a significant impact on the synergistic sterilization effect, with larger particles showing a superior performance due to stronger chain-like structures in the magnetic field. Finally, the Fe₃O₄@Au/PDA nanodurian also demonstrates effective biofilm removal, with larger particles exhibiting the best eradication effect under the photothermal-magnetomechanic treatment. Overall, this magnetic field enhanced photothermal antibacterial strategy provides a promising broad-spectrum antimicrobial solution to combat bacterial infections. Thus, it possesses great potential in future nanomedicine and pollution treatment.

In this work, using tri(5-aminotetrazolium)triazine (H₃TATT) as an energetic ligand, two new energetic complexes (ECs), Cu(HTATT)(H₂O)₂ (EC-Cu1) and [Cu₃(TATT)₂(H₂O)₂]_n (EC-Cu2), have been synthesized under hydrothermal conditions. Their crystal structures, thermal decomposition behaviors and specific heat capacities were determined respectively. In addition, two ECs were combined with GO (graphene oxide) and an MXene (Ti₃C₂T_X) respectively by an in situ growth strategy to obtain four carbon nanomaterials/EC composites, which were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The effects of two ECs and four composites on the thermal decomposition of AP were studied by differential scanning calorimetry (DSC). Among them, the sample containing 8 wt% composite (GO/EC-Cu2) has the best promoting effect on AP, causing the high temperature decomposition peak to overlap with the low temperature decomposition peak of AP, reducing the decomposition peak temperature of AP from 443.6 °C to 308.9 °C, and the heat release is up to 4875 J g⁻¹. Compared with ECs acting solely on AP, composite materials have stronger synergistic and promoting effects. This study provides a new example of the synthesis of carbon nanomaterial/EC composites and the improvement of the performance of AP-based solid propellants.