In this study, we modified Ni based electrodes with MXene and MXene-based composite catalysts for water splitting. The MXene based catalyst exhibited excellent electrochemical surface area (ECSA) of 1840 cm 2 , highlighting its abundant active sites. To further enhance catalytic activity, MXene was modified with graphene oxide (GO) and carbon black (CB), which significantly reduced the overpotential from 300 mV to 196 mV at 10 mA cm −2 and improved the reaction kinetics, as evidenced by a low Tafel slope of 96.35 mV dec −1 . Moreover, the MXene–GO–CB composite demonstrated outstanding long-term durability, maintaining stable operation for 50 h at 100 mA cm −2 with only a 34 mV increase in overpotential at 10 mA cm −2 . These results confirm that the synergistic combination of MXene with GO and CB yields a highly active and durable electrocatalyst, offering strong potential for practical water electrolysis applications.
The paper presents the first comparative study of the microstructure and mechanical properties of gadolinium zirconate ceramics produced by spark plasma sintering of powders obtained using hydroxide precursors synthesized with and without mechanical activation. The initial precursor was prepared via reverse coprecipitation of hydroxides. Mechanical activation of the precursor was performed in an AGO-2 planetary mill at a centrifugal acceleration of 20 g for 30 min. X-ray phase analysis revealed that the resulting ceramics were nanocrystalline. The ceramics produced from the mechanically activated precursor demonstrated superior mechanical properties, including higher microhardness and Young’s modulus, compared to those produced from the non-activated precursor.
In this article, the Cauchy problem in a half-plane is studied for a fourth-order inhomogeneous equation with a fractional derivative in the Caputo sense. The uniqueness of the solution is demonstrated using the Laplace transform. In constructing the solution, partial solutions expressed in terms of Wright functions are first found. Green’s functions are then constructed using these partial solutions. The solution is constructed explicitly using the Green function. An explicit form of the fundamental solution is also obtained.
We study three-particle Schrodinger operators on the two-dimensional lattice Z(2) and show that a critical mass ratio gamma(c) approximate to 2.75194 governs the existence of a bound trimer in the fermionic 2 + 1 configuration (two identical fermions and a third particle). For gamma < gamma(c) there is a topological prohibition (Pauli suppression) of a three-body bound state, whereas for gamma > gamma(c) a doubly degenerate eigenvalue emerges below the essential spectrum with the strong-coupling asymptotics z(gamma, lambda) = -lambda+e(0)(gamma)+O(lambda(-1)). Within a unified framework based on the Birman-Schwinger principle and strong-coupling asymptotic analysis, we compare this behaviour with the bosonic case of three identical particles, where two bound states exist below the essential spectrum and the ground-state energy satisfies z(1)(s) (& micro;) = -3 & micro; + C-2 + O(& micro;(-1)). The resulting second-order phase transition with respect to the mass ratio gamma is relevant for the design of experiments on fermionic trimers in optical lattices and for modelling excitonic complexes and defect-bound states in two-dimensional nanomaterials, where the critical value gamma(c) serves as a design guideline for the observability of three-body bound states. We also outline a modified three-particle lattice model with two competing interaction channels, for which the Birman-Schwinger analysis naturally leads to a Landau-type scenario of a first-order phase transition in the space of trimer bound states. In the bosonic case we prove a strong-coupling theorem describing the existence and asymptotics of trimer bound states, while in the fermionic 2+1 case we establish a spectral phase-transition theorem that identifies an explicit critical mass ratio gamma(c) separating the trimer and non-trimer regimes.
The elastic properties and mechanical characteristics of Ti-Nb22-Zr6 based alloys were calculated using the exact muffin-tin orbital method with the coherent potential approximation. Alloying by metals such as Hf, Mg and their combination were considered, and their concentration did not exceed 5 at.%. It was shown that addition of Hf and Mg leads to a decrease in Young's modulus due to both size effect and electronic factor. The calculated Young's modulus for the ternary Ti-Nb22-Zr6 alloy (70.1 GPa) is found in good agreement with experimental one (70 GPa). The smallest value of Young's modulus was calculated for the Ti-Nb22-Zr6-Hf5-Mg2.5 alloy, achieving 57 GPa. Further increase in Mg concentration leads to a negative C ' and alloy destabilization. Additionally, alloying of the Ti-Nb22-Zr6 alloy results in a decrease in hardness, fracture toughness, but brittleness index is increased.
