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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]

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]

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]

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]

In this report, Mg(0.6)Zn(0.4)Fe2O4 (MZF) and CuxMg(0.6)Zn(0.4)Fe2O4 (CMZF) where (x = 0.2) were synthesized via sol–gel method. The composite of CuxMg(0.6)Zn(0.4)Fe2O4 with reduced graphene oxide (CuxMg(0.6)Zn(0.4)Fe2O4@rGO) was fabricated by wet chemical approach to get over the adverse impacts of toxic dyes and pathogenic bacterial strains. The rGO possesses high stability, larger surface area and an enhanced ability for electron transport during photocatalysis. X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy, Mott Schottky and UV–Visible spectroscopy were used to analyze the physiochemical properties of manufactured materials. Methylene blue (MB) and benzoic acid (BA) degradation was performed under the visible light of the Xenon lamp. The photocatalytic activity of MB exhibited degradation efficiency by MZF, CMZF, and CMZF@rGO was 16.67%, 42.72% and 76.19% respectively and degradation of BA by MZF, CMZF, and CMZF@rGO was 26.92%, 44.44% and 60.42% respectively. The composite (CMZF@rGO) exhibited the best degradation efficiency than bare and doped materials (MZF and CMZF) due to the greater surface area. As surface area increased, the e−/h+ pair recombination rate decreased. Therefore, the photocatalytic efficiency of the material enhanced. It is examined, CMZF@rGO has potential applications in the photocatalytic degradation of organic pollutants. [ABSTRACT FROM AUTHOR]