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High entropy alloys (HEAs) are remarkable engineering materials with a unique structural design and diverse properties, making them widely applicable. This review focuses on their utilization in interfacial joining, offering a systematic summary of their wetting characteristics as both filler alloys and substrates. The wetting and brazing behavior of HEAs in interfacial joining are examined for both filler alloys and substrates. The review also addresses current research limitations and outlines future perspectives for HEAs in interfacial joining applications. This research lays the groundwork for further advancements in the field.

The design and synthesis of high-efficiency electrocatalysts are of great practical significance in electrocatalytic water splitting, specifically in accelerating the slow oxygen evolution reaction (OER). Herein, a self-supported bismuth-doped NiFe layered double hydroxide (LDH) nanosheet array for water splitting was successfully constructed on nickel foam by a one-step hydrothermal strategy. Benefiting from the abundant active sites of two-dimensional nanosheets and electronic effect of Bi-doped NiFe LDH, the optimal Bi0.2NiFe LDH electrocatalyst exhibits excellent OER performance in basic media. It only requires an overpotential of 255 mV to drive 50 mA cm–2and a low Tafel slope of 57.49 mV dec–1. The calculation of density functional theory (DFT) further shows that the incorporation of Bi into NiFe LDH could obviously overcome the step of H2O adsorption during OER progress. This work provides a simple and effective strategy for improving the electrocatalytic performance of NiFe LDHs, which is of great practical significance.

Methyl hydrogen sulfate (MHS) as a common nucleation precursor that has important effect on new particle formation (NPF). Liu et al. showed that MHS and sulfuric acid (SA) generation are competitive due to consumption of the common precursor SO3, and the nucleation ability of SA is better than MHS. Thus, MHS inhibits the SA‐DMA‐based clusters formation particularly in regions with high [MO] (methanol) (Liu et al., Proc. Natl. Acad. Sci. U.S.A.2019, 116, 24,966). However, in regions where [H2O] is much higher than [MO] ([SA] > > [MHS]), the SO3consumed by the generation of less MHS will not significantly reduce the [SA], whether MHS still inhibits SA‐A‐based clusters formation and how MHS affects the growth pathways of MHS‐SA‐A‐based clusters remains unclear. Hence, quantum chemistry calculations combining Atmospheric Cluster Dynamics Code (ACDC) are used to investigate the role of MHS in the SA‐A‐based system. Our conclusions show two different effects of MHS in NPF process: “inhibiting” in regions with high [MO] and “weakly facilitating” in regions with high [H2O] and low [MO]. The growth pathways show that with the increasing [MHS], the role of MHS in NPF gradually changes from “transporter” to “participator”, and the contribution to the pathways increases from 7 to 85%. Our results contribute to understanding the NPF in low‐temperature regions with different concentrations of MO and H2O. MHS inhibits the formation of SA‐A‐based clusters under the regions with high concentrations of MO. However, in the regions where H2O concentration is much higher than the MO ([SA] > > [MHS]), MHS weakly facilitates the formation of SA‐A‐based clusters. With the increase of [MHS], the role of MHS molecules gradually transform from “transporter” to “participator” in NPF.

Polymeric ionic liquid (such as poly[ViEtIm]Br)-modified reduced graphene oxide (rGO), rGO-poly[ViEtIm]Br, was nominated as an open carrier to construct a degradation platform. The large specific surface of rGO together with the anion-exchange property of poly[ViEtIm]Br terminals led to the wide growth of heteropolyanions (like [PW12O40]3–, [PMo12O40]3–, and [SiW12O40]4–), thus assembling the integrated catalyst rGO-poly[ViEtIm][heteropolyanions]. The grafted poly[ViEtIm]Br provided an anchor point to interlink the polar heteropolyanions and the nonpolar rGO substrate, endowing this graphene-based catalyst with excellent dispersibility. The adequate exposure of heteropolyanions further promoted the decolorization capability during the degradation procedure. Morphology, structure, and properties of materials were confirmed and monitored via transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–vis) spectroscopy, etc. rGO-poly[ViEtIm][PW12O40] was selected as the optimal catalyst with degradation efficiency toward methyl orange reaching 98.7% in 3 h. In addition, the excellent structural stability of the catalyst improved the decolorization efficiency, which reached 95% after recycling five times.

Although the ammonolysis of t-N2O4is one of the potential sources of HNO3formation, the available studies have only focused on its naked reaction. Herein, the effect of important neutral and acidic trace gases, water monomer, water dimer, and sulfuric acid, on the formation of HNO3from the ammonolysis of t-N2O4was studied by the quantum chemical method of CCSD(T)/aug-cc-pVTZ//B3LYP-D3/6-311++G(3df,2pd) and the Master equation/Rice–Ramsperger–Kassel–Marcus (ME/RRKM) rate calculations. The quantum chemical results revealed that the ammonolysis of t-N2O4with (H2O)2and H2SO4are barrierless or nearly barrierless reactions, potentially lowering the energy barrier to 3.4–4.1 kcal mol−1. The calculated effective rate constant illustrates that (H2O)2(100% RH) dominates over H2O and H2SO4within the range of 280–320 K (0 km), with an effective rate constant that is 1–3 orders of larger magnitude, whereas H2SO4(108mol cm−3) is the most favorable catalyst within the troposphere between 5 and 30 km. However, the contributions of H2O, (H2O)2, and H2SO4are not apparent in the gas-phase ammonolysis of t-N2O4within the range of 213–320 K and 0–30 km because their effective rate constants were at least 4 orders of magnitude lower than the corresponding rate constant of the ammonolysis of t-N2O4. In general, the current findings shed fresh light on neutral (H2O and (H2O)2) and acidic (H2SO4) catalysts that not only affect energy barriers but also have an impact on the ammonolysis of t-N2O4in neutral and acidic conditions.

NH2SO3H is an effective nucleation agent for the formation of atmospheric aerosols and cloud particles. So, the ammonolysis of SO3to form NH2SO3H without and with neutral (H2O) and basic (NH3) trace gases has been extensively investigated. However, the acidic trace gas X (X = H2SO4and CH3SO3H)-assisted ammonolysis of SO3is still up for debate. In this work, a comprehensive theoretical investigation of X-assisted ammonolysis of SO3and its reverse reaction (the isomerization of NH2SO3H to form SO3–···NH3+) was carried out in the gas phase and at the air–water interface. The gas-phase results show that X-assisted isomerization of NH2SO3H to form SO3–···NH3+is more energetically and kinetically favorable than its reverse reaction and the isomerization of NH2SO3H in the presence of H2O and NH3. Such unexpected findings revealed that gas-phase NH2SO3H is highly reactive in the presence of acidic trace gas in contrast to the high stability of NH2SO3H in neutral and basic conditions. At the air–water interface, the X-assisted isomerization reaction of NH2SO3H involves multiple water molecules. The loop structure of the reaction center (X···NH2SO3H···3H2O) promotes the transfer of protons in the water molecules to form the SO3–···NH3+ion pair, which can then interact with several interfacial water molecules to form ammonium bisulfate. These interfacial reaction channels follow a stepwise mechanism and proceed at the picosecond time-scale. The findings of this study will contribute to a better understanding of the atmospheric behavior of NH2SO3H in polluted acidic trace gases.

Piezoelectric microcantilever transducers based on lead zirconate titanate (PZT) thin film have received considerable interest because of their wide potential applications in nanotechnology, biosensors and microelectromechanical systems. In this work a self-sensing and self-actuating PZT piezoelectric cantilever array is designed and fabricated for parallel dynamic atomic force microscope (AFM) imaging. Carbon nanotube (CNT) tips are assembled to some cantilevers of the array by nano-handling to enhance the imaging quality. Detailed fabrication process of the array and nano-assembly of CNT tips are reported and characterisations of ferroelectric, piezoelectric and mechanical properties of the array are carried out and presented in this paper.

The hydrolysis of CH2OO is not only a dominant sink for the CH2OO intermediate in the atmosphere but also a key process in the formation of aerosols. Herein, the reaction mechanism and kinetics for the hydrolysis of CH2OO catalyzed by the precursors of atmospheric aerosols, including H2SO4, H2SO4···H2O, and (H2SO4)2, have been studied theoretically at the CCSD(T)-F12a/cc-pVDZ-F12//B3LYP/6-311+G(2df,2pd) level. The calculated results show that the three catalysts decrease the energy barrier by over 10.3 kcal·mol–1; at the same time, the product formation of HOCH2OOH is more strongly bonded to the three catalysts than to the reactants CH2OO and H2O, revealing that small clusters of sulfuric acid promote the hydrolysis of CH2OO both kinetically and thermodynamically. Kinetic simulations show that the H2SO4-assisted reaction is more favorable than the H2SO4···H2O- (the pseudo-first-order rate constant being 27.9–11.5 times larger) and (H2SO4)2- (between 2.8 × 104and 3.4 × 105times larger) catalyzed reactions. Additionally, due to relatively lower concentration of H2SO4, the hydrolysis of CH2OO with H2SO4cannot compete with the CH2OO + H2O or (H2O)2reaction within the temperature range of 280–320 K, since its pseudo-first-order rate ratio is smaller by 4–7 or 6–8 orders of magnitude, respectively. However, the present results provide a good example of how small clusters of sulfuric acid catalyze the hydrolysis of an important atmospheric species.