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Recently, layered transition metal oxides have demonstrated voltage windows favorable for use as cathodes in sodium-ion batteries, leading to increased specific capacity and energy density. Here, NaCr0.5Y0.5O2, NaCr0.5Tc0.5O2, and NaCr0.5Rh0.5O2were studied by using first-principles calculations to elucidate their properties. There is a trigonal arrangement in the structure of both pure and substituted NaCrO2. Structural characteristics reveal the ferromagnetic behavior of these compounds (NaCr0.5X0.5O2; X = Y, Tc, Rh). We calculated the density of states and spin-polarized electronic band structures for the three compounds tested. NaCr0.5Y0.5O2and NaCr0.5Rh0.5O2exhibit diluted magnetic semiconductor (DMS) behavior, while NaCr0.5Tc0.5O2has half-metallic (HM) behavior. The substitutional material’s ferromagnetic nature is confirmed by the negative values of the exchange constants (Nօαand Nօβ). The fractional value of the magnetic moment also confirms the DMS nature of NaCr0.5Y0.5O2and NaCr0.5Rh0.5O2, while the HM behavior is confirmed by the integral value of the magnetic moment for NaCr0.5Tc0.5O2. The thermoelectric characteristics were computed using the BoltzTraP code. Alectrochemical analysis of NaCr0.5Y0.5O2showed a theoretical discharge capacity of 400 mhAg−1and an average intercalation voltage of 4.87 V, calculated from the total energies of the optimized compounds and their de-sodianted phases. These theoretical computations demonstrate that the binary layered TM oxides studied are appropriate substances to employ in coin cell fabrication as cathodes.

The synthesis of nanoscale porous coordination network (PCN-224 MOF) is intricate due to the difficulty in spatially influencing typical soluble metal salt chemicals, leading to the formation of bulk MOFs. This study presents the novel utilization of V2CTxas a metal precursor for the preparation of PCN-224 MOF nanostructures, with the ability to modulate the resulting nanostructure by adjusting the reaction temperature. The growth of PCN-224 provides the surface atoms with strong electronegative in V2CTxMXene and the availability of abundant accessible active sites for ligands. This study introduces a novel methodology for fabricating a composite material by integrating V2CTxMXene and PCN-224 MOF. The PCN-224/V2CTxsupercapattery have 185.5C/g specific capacity (Qs) at 2 A/g and an electrode with 82 Wh/kg and 840 W/kg energy density (Ed) and power density (Pd). The electrode exhibited a coulombic efficiency and capacitive retention of 96 % and 82 % after undergoing 15,000 cycles. It has outstanding cyclic stability, maintaining 94 % of charge time and 97 % discharge time after 15,000 cycles. This study suggests using duplicate cell electrodes of PCN-224/V2CTxsupercapattery in daily-use portable devices and oxygen evaluation reaction (OER) investigation. This is the first study to examine PCN-224/V2CTxelectrochemical behavior and propose high-energy, high-rate electrochemical devices use it as an electrode.

We studied the interplay between quantum interference (QI) and molecular asymmetry in charge transport through a single molecule. Eight compounds with five-membered core rings were synthesized, and their single-molecule conductances were characterized using the mechanically controllable break junction technique. It is found that the symmetric molecules are more conductive than their asymmetric isomers and that there is no statistically significant dependence on the aromaticity of the core. In contrast, we find experimental evidence of destructive QI in five-membered rings, which can be tuned by implanting different heteroatoms into the core ring. Our findings are rationalized by the presence of antiresonance features in the transmission curves calculated using nonequilibrium Green’s functions. This novel mechanism for modulating QI effects in charge transport via tuning of molecular asymmetry will lead to promising applications in the design of single-molecule devices.