Search

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]

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]

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]

The rapid recombination of charges of photogenerated electrons and holes severely limits single semiconductor photocatalytic applications. In this study, a simple and facile sol-gel approach was used to synthesize Ba 2- x Ho x Sr 2- y Ni y Fe 12 O 22 ( x = 0, 0.1 and y = 0, 0.5). The composite of holmium-nickel doped barium-strontium ferrite with MXene (Ba 1.9 Ho 0.1 Sr 1.5 Ni 0.5 Fe 12 O 22 @MXene) was synthesized by ultrasonication method. These synthesized samples were subsequently used to photodegrade rhodamine B (RhB) and pendimethalin under visible light illumination. The results of the experiments demonstrated that MXene, as a cocatalyst, considerably reduces the rate of recombination of charges and broadens absorption of visible light by providing increased surface functional groups to improve the photocatalytic activity of synthesized samples. MXene is thermally stable, have high electrical conductivity, have adjustable bandgap, and hydrophilic in nature. The optimized Ba 1.9 Ho 0.1 Sr 1.5 Ni 0.5 Fe 12 O 22 @MXene composite demonstrated an excellent photocatalytic rate by degrading 78.88% RhB and 75.59% pendimethalin in 140 minutes. Moreover, the scavenging experiment revealed that photogenerated electrons and holes were the primary active species involved in RhB and pendimethalin photodegradation, respectively. Ba 1.9 Ho 0.1 Sr 1.5 Ni 0.5 Fe 12 O 22 @MXene showed increased photocatalytic behavior because it has increased surface area which decreases rate of recombination of electron and hole pair, hence photocatalytic activity increases. It is observed that Ba 1.9 Ho 0.1 Sr 1.5 Ni 0.5 Fe 12 O 22 @MXene has potential application in photocatalytic degradation of harmful pollutants., Competing Interests: There are no conflicts of interest to declare for our manuscript being submitted to your journal., (This journal is © The Royal Society of Chemistry.)

Metallic nanowires (NWs) and their different compounds display incredible prospects for their use in various applications including media storage, sensor and solar cell devices along with the biological drug delivery systems. In this research work, the metallic NWs like nickel nanowires (Ni-NWs) are synthesized successfully by employing electrodeposition process. Anodic aluminum oxide (AAO) templates are employed as a platform with copper metal coating which acts as an active cathode. The synthesized Ni-NWs are examined through various characterization techniques including X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) to study the crystal structure, surface morphology and magnetic properties, respectively. The XRD analysis shows the development of various diffraction planes like Ni (111), Ni (200), Ni (220) which confirms the formation of polycrystalline nickel NWs. The SEM analysis reveals that the range of diameter and length of nickel NWs are found to be ∼160 to 200 and ∼4 to 11 micron respectively showing high aspect ratio (ranged from ∼200 to 300). The ferromagnetic behavior of Ni-NWs is confirmed by the hysteresis loop carried out for parallel and perpendicular configurations having H c = 100 and 206 Oe, respectively. The obtained results suggest that the synthesized Ni- NWs may be used for high-density media storage devices., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors.)

Two-dimensional (2D) material-based heterostructures gain increasing interest due to their extraordinary properties and excellent potential for the optoelectronic devices. This study deals with modulation of electronic and optical properties of the ZrS 2 /PtS 2 van der Waals heterostructure under vertical strain and an external electric field based on first principles calculation. Different stacking of ZrS 2 and PtS 2 layers are considered for the heterostructure formation and the most stable structure with lowest binding energy is selected for further calculations. The stable ZrS 2 /PtS 2 heterostructure shows an indirect band gap of 0.74 eV, which is smaller than that of both ZrS 2 and PtS 2 monolayers. With the applied external electric field, the band gap value of the ZrS 2 /PtS 2 heterostructure increases with the negative electric field and decreases with the positive electric field. It is observed that the indirect-to-direct band gap transition occurs when the highest negative value of the electric field is applied. In the case of vertical strain applied to the heterostructure, with an increase in compressive strain, the band gap decreases and vice versa for tensile strain. Optical absorption spectra show significant absorption in the visible light region to the ultraviolet light region. This study shows that the electronic and optical properties of ZrS 2 /PtS 2 heterostructures can be modulated by using vertical strains and an external electric field., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)