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The contamination of water resources by industrialization is the biggest issue over the world and researchers are trying their best for the reduction of water pollution using cost-effective, non-toxic, and reusable photocatalysts. Therefore, this research article outlines the synthesis of manganese-doped iron oxide (Mn0.5Fe1.5O3) using the sol–gel method, and its subsequent combination with graphitic carbon nitride (Mn0.5Fe1.5O3@gCN) through ultrasonication. The resulting materials are investigated for their ability to degrade methylene blue and methyl red organic dyes through mineralization. The fabricated materials were confirmed by X-ray diffraction analysis (XRD), and FTIR spectroscopy, while the UV–visible approach was employed for the determination of optical spectra and bandgap of fabricated photocatalysts. The flat-band potential (0.75 and 0.77 eV) and the type (n-type) of the semiconducting oxides were examined by the Mott–Schottky curves. The prepared photocatalysts degraded 92% methylene blue and 91% methyl red under visible light irradiation for 70 min by pursuing a pseudo-first-order mechanism with rate constants 0.0381 and 0.0316 min−1, respectively. The maximum degradation was observed via Mn-Hem@gCN due to the penetration of the sheets of gCN that enhances the surface area of catalysts by trapping the photogenerated species for the photodegradation of wastewater contaminants. Highlights: Pristine and doped hematite were fabricated by auto-ignition route. The characterization was carried out by using XRD, FTIR, optical analysis, Mott–Schottky, and EIS. Methyl red and methylene blue were used as contaminants. Scavenging studies revealed that electrons were the active species participating in the degradation of contaminants. [ABSTRACT FROM AUTHOR]

Equilibrium molecular dynamics (EMD) simulations have been performed to investigate the structural analysis and thermal conductivity (λ) of semiconducting (8,0) and metallic (12,0) zigzag single-walled carbon nanotubes (SWCNTs) for varying ±γ(%) strains. For the first time, the present outcomes provide valuable insights into the relationship between the structural properties of zigzag SWCNTs and corresponding thermal behavior, which is essential for the development of high-performance nanocomposites. The radial distribution function (RDF) has been employed to assess the buckling and deformation understandings of the (8,0) and (12,0) SWCNTs for a wide range of temperature T(K) and varying ±γ(%) strains. The visualization of SWCNTs shows that the earlier buckling and deformation processes are observed for semiconducting SWCNTs as compared to metallic SWCNTs for high T(K) and it also evident through an abrupt increase in RDF peaks. The RDF and visualization analyses demonstrate that the (8,0) SWCNTs can more tunable under compressive than tensile strains, however, the (12,0) zigzag SWCNTs indicate an opposite trend and may tolerate more tensile than compressive strains. Investigations show that the tunable domain of ±γ(%) strains decreases from (-10%≤ γ ≤+19%) to (-5%≤ γ ≤+10%) for (8,0) SWCNTs and the buckling process shifts to lower ±γ(%) for (12,0) SWCNTs with increasing T(K). For intermediate-high T(K), the λ(T) of (12,0) SWCNTs is high but the (8,0) SWCNTs show certainly high λ(T) for low T(K). The present λ(T, ±γ) data are in reasonable agreement with parts of previous NEMD, GK-HNEMD data and experimental investigations with simulation results generally under predicting the λ(T, ±γ) by the ∼1% to ∼20%, regardless of the ±γ(%) strains, depending on T(K). Our simulation data significantly expand the strain range to -10% ≤ γ ≤ +19% for both zigzag SWCNTs, depending on temperature T(K). This extension of the range aims to establish a tunable regime and delve into the intrinsic characteristics of zigzag SWCNTs, building upon previous work. [ABSTRACT FROM AUTHOR]

Hybrid supercapacitors are energy storage technology offering higher power and energy density as compared to capacitors and batteries. Cobalt-doped manganese oxide (Co@MnO2) was synthesized using an easy and affordable sol–gel process and measured the electrochemical properties. A value of the specific capacity of 1141.42 Cg−1 was obtained which was larger in comparison to the reference sample (MnO2 = 673.79 Cg−1). The value of the specific capacitance was achieved 1902 Fg−1. To design a hybrid supercapacitor device, Co@MnO2 was used as the positive electrode and the activated carbon was employed as the negative electrode in two-electrode assembly. According to calculations, the measured value of the specific capacitance of Co@MnO2 was 713.25 Fg−1. The charge storage mechanism is supported with the help of Randles–Ševčík and Dunn's models. The estimated value of energy and power densities were 3200 Wh kg−1 and 24 Wkg−1, respectively. The stability of this device was checked by putting it to 1000 charging and discharging cycles, and it retained 86% of its initial capacity. Our result provides a platform for enhancing the functionality of energy storage systems. [ABSTRACT FROM AUTHOR]

Supercapattery is an energy storage device which shows high power and energy densities compared to supercapacitors and batteries. A simple and cost‐effective sol‐gel method was used to synthesize the aluminium‐doped cobalt oxide (Al‐Co3O4). The structural, morphological and composition analyses were investigated using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). Further, Brunauer‐Emmett‐Teller (BET) calculations were performed, which showed an enhancement in surface area. The specific capacity of the Al‐doped sample was increased up to 708 C/g compared to the reference sample (Co3O4=420 C/g). A supercapattery device was designed by using the activated carbon as a negative electrode and the Al‐Co3O4 as the positive electrode in two electrode assemblies. The estimated value of the specific capacity of Al‐Co3O4 was 189 C/g. Furthermore, the obtained energy and power density values were 42 Wh/kg and 2080 W/kg, respectively. To investigate the stability, this device was subjected to 5000 charging/discharging cycles that maintained 90 % of its initial capacity. Our findings provide a foundation for improving the performance of energy storage devices. [ABSTRACT FROM AUTHOR]

The space-time correlation function has been obtained in strongly coupled dusty plasmas (SCDPs) using equilibrium molecular dynamics (EMD) simulations. The simulated results for three-dimensional (3D) SCDPs with suitable normalization are computed over a wide domain of plasma parameters (Γ, κ) in a microcanonical ensemble. The EMD simulations indicate that different modes of propagated wave in SCDPs are analyzed for four different values of wave number (k). New investigations of normalized longitudinal current correlation function CL(k, t) show that the amplitude of oscillation and frequency of propagated modes increase with an increase in k. The obtained results for longitudinal modes of oscillation indicate that the dust particles remain in damping behavior at the low Γ, damped oscillation with decreasing amplitude inside decaying exponential envelope at intermediate Г, and sinusoidal oscillation at high Г, depending on κ. The system size (N) does not significantly affect the propagated modes of oscillation, while the periodic oscillation shifts toward higher Γ with increasing N and κ. The computations show that normalized longitudinal CL(k, t) current correlation particularly depend on Coulomb coupling (Γ), Debye screening (κ), and wave number (k). In our simulations, the frequency and the amplitude of oscillation of the dust particles decrease with an increment of κ and system size (N), but the frequency increases and the amplitude decreases with increasing Γ, as expected. It has been demonstrated that the EMD method is used to study the different propagated modes in dusty plasma systems and can be used to predict the damping behavior, damped oscillation, and periodic phenomena in 3D strongly coupled SCDPs. [ABSTRACT FROM AUTHOR]

Inverse perovskites are the counterparts to the largest family of crystalline perovskite materials and have attracted significant research interest because of their unconventional physical and chemical properties. Perovskite materials have been studied widely; however, less attention has been paid to their counterparts (inverse perovskites). In the present study, we report on the structural, electronic, elastic, mechanical, magnetic and thermodynamic properties of unexplored Rh-based XCRh3 (X = Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Nb, Mo, Tc, Ru, Pd, Ag) inverse perovskites. The first-principles density functional theory-based linearized augmented plane wave method as implemented in the Wien2k package with the generalized gradient approximation was employed for the investigation of the physical properties. The computed formation energies showed that the majority of these materials comparatively favor the ferromagnetic phase over the non-magnetic phase. Amongst the studied XCRh3, X = Ti-, V-, Cr-, Mn-, Zn- and Zr-based materials comprise negative formation energies confirming the energetic stability. All the compounds other than NbCRh3 and MoCRh3 were found mechanically stable. Spin-projected electronic properties of XCRh3 revealed the conducting features in both spin versions. The large magnetic moments per unit cell (> 3μB) of CrCRh3, MnCRh3, FeCRh3 and TcCRh3 were observed with dominant contribution from X-atoms. Mechanical anisotropy and other bulk mechanical parameters are elaborated and discussed in detail. The thermodynamic properties including specific heat capacity, thermal expansion coefficient and Debye temperature are scrutinized at different temperature and pressure ranges. [ABSTRACT FROM AUTHOR]

Cadmium ferrites belong to normal spinel ferrites, and they exhibit interesting electrical, magnetic, and optical properties. The pure and cerium-doped cadmium ferrites CdFe2−xCexO4 (x = 0.0, 0.125, 0.250, 0.375, 0.5) were synthesized by a chemical co-precipitating technique using sodium hydroxide as a co-precipitating agent. The structures and phase purity of fabricated nanomaterials were analyzed by X-ray diffraction (XRD). The crystallite size for all the prepared nanomaterials was in the range of 28–46 nm. The lattice constant and unit cell volume were found to decrease with the increasing concentration of Cerium, which was confirmed by the peak shift in the XRD pattern. The X-ray density for all nano ferrites increased with the enhancement of cerium composition. The resistivity of the nanomaterials has random behavior with the enhancement of cerium composition for a temperature, but the value of resistivity at x = 0.125 has the lowest value and at x = 0.375 has the highest value for almost all temperatures. For specific concentrations, a decreasing trend of resistivity of fabricated materials was found with an increment of temperature. The activation energies were also calculated, and it increased for x = 0.125 and then decreased for all the nanomaterials. For the confirmation of the M–O bonds, FTIR analysis of all the nano ferrites was also performed. The analysis shows a higher frequency absorption band in the range of 531.24–534.84 cm−1. This absorption band confirms that metal oxides are formed in all the synthesized nanoparticles. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide (TMD) material-based van der Waals (vdW) heterostructures have gained huge attention due to their superior capabilities and multiple functionalities in electronics and optoelectronic devices. In this work, a gallium telluride/hafnium selenide (GaTe/HfSe2) vdW heterostructure with excellent ohmic contacts is studied. A high gate-modulated rectification ratio (RR) of 6.3 × 105 is attained. Furthermore, the photovoltaic measurement is performed under the illumination of laser light of a wavelength of 532 nm and various powers (20–100 μW). Its rise and decay times (18 μs & 24 μs) are superior among those of various reported vdW heterostructures. The photoresponsivity of GaTe/HfSe2 is enhanced significantly up to with an external quantum efficiency (EQE = 54%) as compared to those of the various reported vdW heterostructures. Such TMD based heterostructure devices would improve the energy harvesting needs along with the multifunctional logic operations. [ABSTRACT FROM AUTHOR]

We report the dopant- and size-dependent variations in high-frequency magnetic and electrical transport properties of Ho-substituted Li-Mn polycrystalline ferrites. Thermal stability and phase identification were confirmed by thermal gravimetric analysis and X-ray diffraction experiments. The overall average crystallite size decreased from 29.6 to 17.5 nm, whereas the bulk density increased from 3.47 to 4.29 g/cm 3 with increasing Ho content. Ferromagnetic resonance (FMR) measurements at the X-band revealed significant shifts in FMR linewidths and resonance positions as a function of composition. Both, FMR linewidth and porosity, were found to decrease with the systematic addition of Ho from 2538 to 2359 Oe and from 26% to 15.4%, respectively. The substitution of Ho 3+ for Fe 3+ reduced the net magnetization of the spinel lattice from 53 to 41 emu/g. Electrical measurements revealed that the resistivity is higher in samples with smaller grains possessing a greater number of thin insulating grain boundaries. The activation energy ∆ E required for hopping increases from 0.09 to 0.16 eV with Ho addition, which may be well explained by the increase in resistivity. The substitution of Ho 3+ for Fe 3+ causes a decrease in Curie temperature T c due to the damping of A-B exchange interactions. [ABSTRACT FROM AUTHOR]

A comprehensive study on structural, spectral, magnetic and dielectric properties of holmium substituted (Ho 3+ ) lithium ferrites; Li 1.2 Co 0.4 Ho x Fe 2−x O 4 (x = 0.00–0.15) synthesized via auto-citric combustion route has been carried out. The annealing temperature essential for complete decomposition of precipitates and spinel phase formation was found around 950 °C which was estimated from thermo-gravimetric analysis (TGA). The development of face centered cubic (FCC) spinel structure was confirmed from X-ray diffraction (XRD) analysis. However, the traces of an ortho phase (HoFeO 3 ) were appeared for x ≥ 0.06 indicating the solubility limit of Ho 3+ ions. The lattice constant ′ a′ increased from 8.351 to 8.360 Å upon Ho addition up to x = 0.06 and it decreased thereafter from 8.360 to 8.352 Å. This decrease in lattice constant was attributed to the secondary phase formation revealing segregation of Ho 3+ ions at grain boundaries. The porosity was found to decrease from 44 to 23% by the inclusion of Ho 3+ ions. Fourier transform infrared spectra (FTIR) exhibited tetrahedral ( v 1 ) and octahedral ( v 2 ) intrinsic vibrational bands at 627 cm −1 and 479 cm −1 respectively and these bands revealed a shift with increasing Ho concentration. The variations in force constants ( K o and K t ) were calculated and discussed with the tetrahedral (r A ) and octahedral (r B ) bond length trends. The dielectric parameters have been investigated as a function of composition and frequency. The systematic addition of Ho gradually increased the ac conductivity from 8.97 × 10 3 to 5.56 × 10 4 (Ω-cm) −1 up to x = 0.12 and it subsequently decreased for x = 0.15. The complex impedance examination (Cole-Cole plots) confirmed a grain-interior phenomenon, effectively contributing to the dielectric properties. The coercivity was enhanced while the saturation magnetization (Ms) was lessened by the incorporation of Ho 3+ ions. The maximum value of coercivity (706 Oe) was obtained for Li 1.2 Co 0.4 Ho 0.12 Fe 1.88 O 4 . The improved coercivity may suggest their utilization in perpendicular recording media applications. [ABSTRACT FROM AUTHOR]