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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]

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]