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In this work, copper oxide nanorods and iron oxide nanospheres were prepared via a coprecipitation method. Moreover, binary composite of copper and iron oxides (CF) and their ternary nanocomposite with MXene sheets (CF/MXene) were synthesized using an ultrasonication approach. The photocatalytic degradation of rhodamine B (RhB), a colorless organic pollutant benzoic acid, and harmful herbicide pendimethalin was investigated under visible light irradiation in the presence of a CF/MXene composite. The photocatalysts were examined using various physiochemical techniques. Ternary CF/MXene nanocomposite showed rapid adsorption of Rh.B with a greater capability than the other prepared photocatalysts. The dye removal after 120 min in the presence of CF/MXene was 94%, with the highest rate constant of 0.01794 min–1. The scavenging experiments proved that the photoactive species involved during the complete photocatalytic process followed the order HO•> O2•–> h+> e–. In short, the synergistic effect of binary composite (CF) and MXene sheets effectively facilitates the photocatalytic degradation of organic pollutants and shows promise for environmental remediation applications.

We have successfully synthesized bare and Na+preintercalated MnO2nanowires (NWs) (NaxMnO2, x= 0.05, 0.1, and 0.15) using a facile hydrothermal method. Supercapacitors are the state-of-the-art technology to overcome the global energy crisis, owing to their fast charging/discharging rates and higher power density. One-dimensional morphology (nanorods, nanowires, etc.) boosts the inherent low conductivity of transition metal oxides including MnO2by confining charge transport only in one direction. Here, we have preintercalated Na+ions into MnO2nanowires (NWs) as a conductivity booster as well as a tunnel-stabilizing agent for α-MnO2. Morphological analysis reveals that nanowires have <50 nm diameter and their surface gets cracked with Na+preintercalation, offering a less dead area. Linear sweep voltammetry (LSV) results revealed an increase in oxygen evolution overpotential by Na+preintercalation, which can enable the supercapacitor to operate at an extended potential window. Na+preintercalation and control on morphology not only increased the conductivity but also shielded the electrode pulverization against tedious charging/discharging cycles and reduced the electrolyte diffusion pathway. These features enabled Na0.10MnO2NWs to exhibit a specific capacitance of 1061 F g–1@1 A g–1and an excellent rate capability of 85.6% at 9 A g–1along with 95.9% capacitance retention after 6000 charging–discharging cycles at 12 A g–1current density. This study showed that Na+preintercalation in MnO2could improve the electrochemical performance and open up new horizons to manufacture high-performance next-generation supercapacitors.

Recently, metal selenides have gathered considerable attention for use as electrode materials for supercapacitor applications because of their substantial theoretical capacities. However, sluggish ion transport and chemical or mechanical degradation of electrode materials during continuous operation severely hamper their electrochemical performance. Herein, we have assembled MnSe (∼10–12 nm) into a 3D Ti3C2Tx/rGO aerogel scaffold with bimodal pore size distribution through a low temperature hydrothermal method, followed by freeze-drying. A 3D percolation network of as-prepared MnSe/Ti3C2Tx/rGO aerogel (MnSe/TCGA) improved electrolyte penetration by providing multidimensional ion transmission channels. High intrinsic conductivity of Ti3C2Txin combination with rGO facilitated electronic transport during electrochemical activity. Cellular sieves of the MnSe/TCGA aerogel scaffold effectively interlocked MnSe particles and thereby prevented pulverization and aggregation of active material. Consequently, a MnSe/TCGA electrode with a specific architecture exhibited a significant specific capacity of 225.4 mAh/g at 1 A/g and maximum initial Coulombic efficiency of 99.5%, which surpassed the values obtained for its counterparts (i.e., MnSe/GA and MnSe). Furthermore, MnSe/TCGA showed an excellent rate capability (158 mAh/g at 12 A/g) and a superb life span (92.1% over 5000 cycles). When examined through impedance studies, MnSe/TCGA revealed low series and charge transfer resistances (Rs= 2.6 Ω and RCT= 5.2 Ω). Overall, as-obtained findings provide insight on constructing high performance 3D porous and hybrid microstructures to optimize electrochemical energy storage performance.

Nanoparticles of tungsten oxide are widely used in advanced chemical processes but the application of tungsten oxide (WO3) in photocatalysis is limited. To increase their application in photocatalysis, nanostructured tungsten oxide (W-1) is co-doped with silver and copper (W-2), and nanocomposites with g-C3N4(W-3) and CNTs (W-4) are synthesized. Structural, elemental, and morphological analyses of prepared samples were carried out using different characterization techniques like XRD, SEM, FTIR, EDX, and Mott-Schottky. The bandgap of WO3is 2.75 eV which is reduced to 2.32 eV by doping and composite formation. The degradation of crystal violet and chlorpyrifos is done to check the photocatalytic performance of prepared materials under the light bulb energy. Photodegradation experiment shows 83.33 % and 41 % degradation of CV and chlorpyrifos respectively. The higher degradation ability is shown by CNTs composites because they have smaller crystallite size (12.81 nm) as compared to other photocatalysts. In the presence of CNTs, the rate of recombination of holes and electrons decreases, resulting in the enhancement of photocatalytic activity. The research reveals that W-4 exhibits promising potential for applications in the photodegradation of organic wastes.

In the present manuscript, a highly efficient, sensitive, and selective sensor based on thiamine-modified Ag–Cu bimetallic nanoparticles was designed for trace-level determination of 4-aminoantipyrine (4-AAP). The prepared nanocomposite Th@Ag–Cu was characterized by X-ray diffraction (XRD), UV–visible spectroscopy, and field emission scanning electron microscopy (FESEM). The electrochemical behaviour of 4-APP on the Th@Ag–Cu nanocomposite-modified glassy carbon electrode (GCE) was investigated in 0.1 M NaOH solution by square wave voltammetry (SWV). Compared with the bare GCE, the proposed electrode showed improved analytical signal in detecting 4-AAP. Under optimum experimental parameters, the proposed sensor displayed good linear responses to concentrations ranging from 0.01 to 500 μΜ. The detection limit and sensitivity were calculated as 0.01 and 1.03 μA/μM, respectively. The modified sensing platform exhibited good selectivity, sensitivity and excellent discrimination ability for 4-AAP in the presence of various interfering agents. Moreover, it also offered excellent reproducibility and long-term stability. Hence, the proposed sensor can be a promising candidate for the monitoring of other anti-inflammatory drugs.

In the current investigation, copper substituted cobalt manganese spinel oxide (CuxCo1–xMn2O4) photocatalyst was prepared via the co-precipitation method. The synthesized nanoparticles were characterized by X-ray diffraction, field emission scanning electron microscopy, and Fourier-transform infrared spectroscopy. The prepared Cu0.2Co1–0.2Mn2O4nanoparticle exhibited excellent photocatalytic activity for degradation of typical organic-based dye Methylene blue (MB). Furthermore, the comparative study of pure CoMn2O4and Cu-substituted CoMn2O4nanoparticles (NPs) towards the photocatalytic performance was also conducted. As compared to the CoMn2O4nanoparticles, the CuxCo1–xMn2O4nanoparticles exhibited excellent photocatalytic capability for the degradation of MB dye. After 80 min of visible light irradiation, the decomposition of MB by CuxCo1–xMn2O4nanoparticles was higher as compared to degradation MB dye in the presence of copper substituted CoMn2O4NPs. Copper substituted cobalt manganese oxide nano-photocatalyst was also used for comparative study. The Cu0.2Co(1–0.2)Mn2O4showed excellent (~86%) photocatalytic performance in contrast with Cu0CoMn(1–0)O4(22%), Cu0.5Co(1–0.5)Mn2O4(57), Cu0.1Co(1–0.1)Mn2O4(60%), Cu0.15Co(1–0.15) Mn2O4(73%) for the degradation of MB in visible light irradiation. The enhanced photocatalytic activity is mainly attributed to the optimized bandgap, which might have developed by the inclusion of copper ions into the CoMn2O4spinel oxide. The copper substitution not only contributed to the inhibition of photo-induced electron–hole pairs but also assisted a great redox capability. CuxCo1–xMn2O4photocatalyst holds great potential for massive pollutant treatment due to the superb photocatalytic performance for organic pollutants.

The current study is based on the synthesis and characterization of ZnO–NiO/rGO nanohybrid for photocatalytic degradation of organic pollutants. The physicochemical properties of synthesized products were estimated by X-ray diffraction technique (XRD), Fourier transform infrared spectroscopy (FTIR), field emission-scanning electron microscopy (FESEM), and Ultraviolet–Visible spectroscopy. The diffraction data showed the formation of binary metal oxide nanocomposite, containing ZnO in hexagonal whereas NiO in the cubic crystalline phase. XRD results revealed that the calculated crystallite size of NiO and ZnO in the ZnO–NiO nanocomposite was <20 nm. The spectroscopic results were found to be in close agreement with XRD data. The morphological analysis exposed the nano-island morphology of the product. The solar light assisted photocatalytic degradation outcome showed 89% degradation of methylene blue and 51% degradation of benzimidazole under similar conditions using ZnO–NiO/rGO nanohybrid. Moreover, the experiment showed that hydroxyl radicals, electrons, and holes were the main active species during the degradation mechanism. In contrast to the ZnO–NiO nanocomposite, the ZnO–NiO/rGO nanohybrid exhibited greater degradation efficiency. This superb photocatalytic performance of ZnO–NiO/rGO nanohybrid proved to be a durable candidate in the field of catalysis.

The expanding population and extensive usage of energy-consuming sources are the main factors driving the interest of current researchers toward the development of extremely effective and useful electrode materials for high-power energy storage devices. A novel class of 2D transition metal carbides such as MXene has captured significant attention and has distinguished itself from other electrode materials because of its remarkable electrochemical characteristics. In this work, we have fabricated MoO3and MnFe2O4via a simple co-precipitation method. Further, we design multifunctional MoO3/MnFe2O4/MXene composite by the combination of MoO3/MnFe2O4and MXene through the sonication route. SEM results confirmed the fabrication of nanorods of MoO3and nanoparticles of MnFe2O4, sandwiched within the MXene sheets. As evident from CV profiles, at 10 mVs−1MoO3/MnFe2O4@MXene showed a higher specific capacitance of 817 Fg−1than other electrode materials mainly because the combined effect of MoO3/MnFe2O4and the conductive nature of MXene sheets. Furthermore, even after 10,000 cycles, MoO3/MnFe2O4/MXene demonstrated outstanding cyclic stability, maintaining 90.2 % retention of its initial specific capacitance. Furthermore, MoO3/MnFe2O4/MXene showed less solution resistance and charge transfer resistance than all other prepared materials. The findings suggest that the MoO3/MnFe2O4/MXene composite is a competent capacitive material in the supercapacitor research area.

Recently, the MXene itself and its composites with various metal oxides have shown excellent electrochemical performance due to the presence of multiple oxidation states. However, the restacking of MXene layers and poor electrical conductivity of metal oxides are major bottlenecks in their effective electrochemical transport, when they are applied individually. Herein, we report a novel manganese oxide/MXene (MnO2/MXene) composite material to overcome these critical issues. Sub-50 nm-thick MnO2nanowires (NWRs) were introduced inside the MXene to effectively stop the restacking as well as to increase the surface area of the supercapacitor (SC) electrode material. The special control on the thickness of NWRs is not only providing an opportunity to adjust them inside the MXene layers but also giving a high surface area. Electrochemical studies suggested that the MnO2/MXene composite behaves as an excellent electrode material for hybrid SCs, as compared to individual MXene and MnO2. Maximum specific capacitance (Csp) of MXene, MnO2NWRs, and MnO2/MXene composite was observed to be about 527.8, 337.5, and 611.5 F/g, respectively. The calculated specific capacity of the MnO2/MXene composite was about 489.5 C/g at 1 A/g, which shows better performance as an electrode material for energy storage devices. The synthesized electrode material demonstrated excellent capacitance retention of about 96% up to 1000 cycles.

Co-precipitation route was used to synthesize different oxides of transition metals nano photocatalysts (Fe2O3, MnO2, Co3O4, and ZnO). The crystal structure, morphology, and elemental composition confirmation were carried out energy dispersive X-ray spectroscopy through X-ray diffraction (XRD), field emission scanning electron microscopy, and EDXS techniques. XRD analysis results revealed that the transition metal oxides are highly pure and have a very small crystallite size. It was found that iron oxide and cobalt oxide nanostructures were cubic, whereas manganese oxide, and zinc oxide nanostructures have tetragonal crystal structures. Fourier transform infrared spectra were studied to further confirm and clarify the material’s structure. Surface areas of the synthesized transition metal oxides nano photocatalysts were calculated through Brunauer–Emmett–Teller isotherms. The calculated optical band gap energy for different metal oxides was between 2.02 and 2.7 eV. The nano photocatalysts were applied in the presence of aqueous methylene blue solution under visible light incandescence in order to set up the ascendancy of heterogeneous photocatalysis. It is observed that the photocatalytic efficiency of the oxides of transition metals simply depends upon the particle size of the nano-sized material and its surface area. It is concluded that iron oxide nano-photocatalyst reveals the best photocatalytic efficiency because of the high surface/charge ratio and variation in surface orientations. It is suggested that nano-sized iron oxides (Fe2O3) is a propitious candidate to resolve environmental issues related to the poisonous ecosystem because it has a great potentiality in heterogeneous photo disintegration and can establish a better green environment.

A potential electrode material, besides the higher specific capacitance, should also exhibit superior cyclic stability and good rate capability. Here, we have fabricated urchin-like hierarchical Co3O4nanoarchitecture directly on the Ni-foam (NF) by a scalable hydrothermal and post-sintering treatment. The as-fabricated Co3O4/NF electrode shows higher pseudocapacitance (PSCs) of 848 Fg−1(at1 Ag−1) and good rate capability as it retains 84.6% of its initial PSCs (at 1 Ag−1) at 10 Ag−1. Furthermore, fabricated Co3O4/NF electrode also exhibits superior cyclic performance as it holds 95.7% of its initial PSCs after 5000 CV tests. The outstanding percentage coulombic efficiency of 99.1% at 10 Ag−1also confirms the feasibility and cyclic-reversibility of the Faradic reaction. The observed superior capacitive behavior of Co3O4/NF electrode is accredited to its binder-free design, uniform architecture, and urchin-like open structure. These observed electrochemical results suggest that Ni-foam supported urchin-like hierarchical Co3O4nanoarchitecture is the promising electrode material for high-performance hybrid supercapacitors applications.

In this work, we are reporting the facile synthesis of hierarchically porous CuO microspheres and their r-GO based nanohybrid as an electrode material for supercapacitor applications. The fabricated product was characterized by powder X-ray diffraction technique (PXRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis, and Brunauer–Emmett–Teller (BET) analysis. PXRD analysis showed the existence of the monoclinic phase of CuO. The compositional study of the synthesized product was completed via EDX analysis. The FESEM analysis confirmed the hierarchical porous micro-spherical architecture of the product with smaller CuO grain-size particles, quasi-microporous spindle-like nanosheets assembled by nano-grains, and their aggregation to mesoporous nature. The BET analysis revealed that the BET and Langmuir surface area of the hierarchically porous CuO microspheres was 60.02m²/g and was 86.68m²/g. Furthermore, the BET results also confirmed the mesoporous structure of the fabricated sample. The hierarchically porous CuO microspheres showed a specific capacitance of 402F/g at 1 A/g with 75.4% capacitance retention whereas their r-GO based nanohybrid showed 712F/g at 1 A/g with 96.9% capacitance retention. The greater electrochemical response of r-GO based nanohybrid was due to the greater surface area and higher electrcial conductivity arise from the synergistic effects between the novel structure and r-GO nanosheets. Moreover, apart from the condcutive matrix r-GO also behaves as a capacitive supplement and contributes toward the total capacitance of the nanocomposite. The electrical impedance spectroscopy (EIS) experiments reveal that the addition of the r-GO matrix also facilitates the charge transfer and improves the kinetics of the redox reaction. In short, it can be concluded that r-GO based hierarchically porous CuO microspheres found themselves as a potential candidate in the field of hybrid supercapacitors.

The development of highly efficient electrode materials for high power devices is one of the cutting-edge research areas in advanced energy applications. Recently, MXene has gained tremendous interest among the research community because of its extraordinary electrochemical properties as compared to other two-dimensional layered materials such as graphene/MoS2. However, the supercapacitive performance of MXene as an electrode material is hindered by the restacking of its layers due to functional group interactions. To overcome this problem, here in this article, we explored MXene and its composites with cobalt ferrite [CoFe2O4] nanoparticles (CoF NPs) for battery-like hybrid supercapacitor applications. NPs were applied to use them as interlayer spacers between MXene layers. By the electrochemical studies, it is proved that the composite (CoF/MXene) can provide better electrochemical properties than individual ferrite or MXene. The maximum specific capacitance (Csp) of CoF NPs, MXene, and CoF/MXene composites was observed to be about 594, 1046.25, and 1268.75 Fg–1at 1 A g–1, respectively. The calculated specific capacity (sp. capacity) of the CoF/MXene composite was about 440 Cg–1at 1 A g–1and proved to be an excellent hybrid electrode material by providing only 0.25 Ω charge transfer resistance. The as-synthesized material demonstrated the excellent capacitance retention, about 97%, up to 5000 cycles.

In this work, nanocrystalline NiDyxFe2-xO4ferrites (0.0 ≤ x ≤ 0.1) were synthesized via co-precipitation route. The impact of Dy+3substitution on the various properties has been investigated. Structural, electrical, spectral and magnetic parameters were measured by XRD (X-ray diffraction), I–V (current-voltage), FTIR (Fourier transform infrared spectroscopy) and VSM (vibrating sample magnetometer) respectively. Morphological analysis was done by FE-SEM (Field emission scanning electron microscope). The formation of a single-phase FCC cubic spinel structure was confirmed by XRD patterns. With the help of XRD data, bond lengths and ionic radii were also calculated. FTIR spectra showed the formation of two typical frequency bands (υ1and υ2) which represent metal-oxygen (M–O) vibrations at octahedral (B) and tetrahedral (A) sites. EDX spectrographs confirmed elemental composition. The MH curves demonstrated a decrease in saturation magnetization (Ms) and Bohr magneton (nB). The coercivity (Hc) showed a non –linear behaviour while anisotropy constant first increased and then decreased with Dy-substitution. NiDy0.025Fe1.975O4showed maximum coercivity (102.06 Oe).

Graphitic carbon nitride (g-C3N4), a structural analogue of graphite has opened a new arena in energy storage. The N-rich g-C3N4sheets similar to N-doped carbon materials provide large number of defect sites for increased diffusion and adsorption of electrolyte ions. High N-content in g-C3N4is most suitable to escalate metal‑carbon binding energy which stabilizes the pseudo-active transition metal oxides/chalcogenides over carbon support to realize high capacitive performance. In this study, we have impregnated binary Ag-BiVO4/Bi2S3heterostructures on g-C3N4sheets through wet-chemical approach, as novel electrode material for supercapacitor application. As prepared Ag-BiVO4/Bi2S3@g-C3N4composite (ABVBS@g-C3N4) along with Ag-BiVO4/Bi2S3(ABVBS), Ag-BiVO4(ABV), and Bi2S3(BS) were systematically characterized by different techniques i.e., XRD, FTIR, FESEM, EDS, and BET analysis. When applied for electrochemical tests, among all the analyzed electrodes ternary composite ABVBS@g-C3N4exhibited highest electrochemical activity with a specific capacitance value of 872 F/g (@5 mV/s) and 815.4 F/g (@1 A/g), and 91.5 % capacitance retention up to 5000 GCD cycles. The initial coulombic efficiency of ABVBS@g-C3N4was noteworthy (99.42 %) due to very low internal resistance. Moreover, it was analyzed that ternary composite ABVBS@g-C3N4has lower equivalent series resistance (RES) as 6.73 Ω and charge transfer resistance value as 7.73 Ω, in comparison to other electrodes. This excellent electrochemical performance of ABVBS@g-C3N4is attributed to combined contributions from ABVBS and g-C3N4in terms of multiple redox states, increased wettability of electrode, and high structural and chemical stability. Considering the results, our study proposes feasible strategy to generate hybrid electrode materials with optimized properties to serve as energy storage material for next generation supercapacitors.

Recently, hybrid electrode materials based on cross-linked carbon analogues have gained significant consideration for their excellent cyclic stability and high specific capacities. This work presents the fabrication of copper and holmium co-doped cobalt ferrite with cross-linked graphene (denoted as CH-CoF/CLG) through one-step hydrothermal route, as novel electrode material for supercapacitor study. The electrochemical performance of CH-CoF/CLG along with its counterparts i.e., CoF, CH-CoF was evaluated through CV, GCD, and EIS analysis using three electrode system. The specific capacitance (Csp) of CoF, CH-CoF, and CH-CoF/CLG nanocomposite at a sweep rate of 5 mV/s is 458 F/g, 762 F/g, and 1258 F/g, respectively, within a potential range of 0.0 to 0.6 V. For CH-CoF/CLG, the calculated slope value (b = 0.84) using power law showed that the energy storage mechanism is based on both capacitive and diffusional processes. The GCD test showed that CH-CoF/CLG exhibited long discharge time (td = 615 s), as compared to CH-CoF (td = 409 s), and CoF (td = 264 s). Moreover, after the fabrication of CH-CoF with CLG, the value of equivalent series resistance (ESR) and charge transfer resistance (Rct) for CH-CoF/CLG were decreased to 0.74 Ω and 0.84 Ω, compared to CoF (1.18 Ω and 1.29 Ω) and CH-CoF (0.88 Ω and 1.0 Ω). When tested for cyclic stability, CH-CoF/CLG displayed insignificant loss in performance up to 3000 cyclic runs. The high supercapacitor performance of CH-CoF/CLG can be assigned to the combined effects arising from the co-doping of transition metal and rare earth metal ions (Cu+2and Ho+3) into CoF lattice, porous cross-linked structure, high wettability, low intrinsic resistance, and easy accessibility of KOH ions into deep layers of active material. As obtained results deduce that the CH-CoF/CLG nanocomposite is a competent capacitive material for energy storage.

The present work develops an eco-friendly protocol that was adopted to synthesize silver nanoparticles (AgNPs) from the aqueous extract of Corchorus depressuscollected in three different seasons. Visually, the formation of AgNPs was confirmed by the change in the color of extracts to reddish brown and the AgNPs were further characterized by ultraviolet–visible studies of the absorption band at 435–450 nm that is due to surface plasmon resonance of AgNPs. The functional groups that behave as a reducing agent and those that act as a capping agent were determined by the FTIR. The particle size was determined by scanning electron microscopy and the amount of capping agents (organic contents at the surface of AgNPs) was estimated by thermogravimetric analysis. AgNPs showed a remarkable inhibitory activity against α-glucosidase compared to their respective aqueous extracts. Extraction of plant material collected in the month of January and their AgNP formation showed the smallest particle size of 4 ± 2 nm. Moreover, an augmented remarkable inhibitory activity against the carbohydrate-digesting enzyme α-glucosidase with IC50of 2·48 ± 0·56 μg/ml was also observed compared to other extracts.

Background: Spinel ferrites have great scientific and technological significance because of their easy manufacturing, low cost and outstanding electrical and magnetic properties. Nickel ferrite nanoparticles are ferromagnetic material with an inverse spinel structure. They show remarkable magnetic properties and hence have a wide range of applications in magnetic storage devices, microwave devices, gas sensors, telecommunication, drug delivery, catalysis and magnetic resonance imaging. Objective: The aim and objective of this research article is to study the relative effect of NiErxFe2-xO4 nanoparticles and their composites with reduced graphene oxide (rGO) for the photocatalytic degradation reaction and other physical parameters. Method: Rare earth Er3+ substituted NiErxFe2-xO4 nanoparticles were synthesized via the facile wet chemical route. Six different compositions of NiErxFe2-xO4 with varied Er3+ contents such as (x) = 0.00, 0.005, 0.01, 0.015, 0.02 and 0.025 were selected for evaluation of the effect of Er3+ on various parameters of NiFe2O4 nanoparticles. Reduced graphene oxide (rGO) was prepared by Hummer's method and was characterized by UV-Visible spectroscopy, X-ray powder diffraction and Raman spectroscopy. Nano-heterostructures of NiErxFe2-xO4 with rGO were prepared by the ultra-sonication method. Results: X-ray powder diffraction (XRD) confirmed the spinel cubic structure of all the compositions of NiErx- Fe2-xO4 nanoparticles. The photocatalytic degradation rate of methylene blue and congo red under visible light irradiation was found faster in the presence of NiErxFe2-xO4-rGO nanocomposites as compared to bare nanoparticles. It was also investigated that as the Er3+ contents were increased in NiErxFe2-xO4 nanoparticles, the dielectric parameters were largely affected. The room temperature DC-resistivity measurements showed that the Er3+ contents in NiFe2O4 are responsible for the increased electrical resistivity of ferrite particles. The electrochemical impedance spectroscopic (EIS) analysis of NiErxFe2-xO4 nanoparticles and NiErxFe2-xO4-rGO nanocomposites revealed that the ferrite particles possess low conductance as compared to the corresponding composites with graphene. Conclusion: The data obtained from all these characterization techniques suggested the potential applications of the NiErxFe2-xO4 nanoparticles and NiErxFe2-xO4-rGO nanocomposites for visible light driven photo-catalysis and high-frequency devices fabrication.

Multiferroic ceramics (BiFeO3) co doped with Yb and Ni cations (Bi1–xYbxNiyFe1–yO3) were synthesized via micro-emulsion route. The dopant (Yb and Ni) contents were fixed x = 0.0 < x >0.125 and y = 0.0 < x >0.25 for six different compositions. The fabricated ceramics were examined with various techniques to index certain features such as crystal habitat, electrical, dielectric, magnetic, and photocatalytic properties. Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), ultraviolet/visible spectroscopy, impedance analyzer constant, current–voltage (I–V) behavior, and vibrating sample magnetometer (VSM). XRD crews revealed a highly crystalline rhombohedral (R3c) structure growth on inclusion of ytterbium and nickel cations in BiFeO3ceramics. However, on substituent concentrations, x = 0.125, y = 0.25 moles, the diffraction pattern (111) against 2θ = 27° showed a phase transformation from rhombohedral to orthorhombic phase. Nanocrystalline morsels were harvested with sizes ~21–23 nm. The fabricated ceramics exhibited the resistivity 1.4 × 109Ω cm–1. The VSM analysis of fabricated ceramics revealed a notable enhancement of magnetization up to 1.51 emu/g for x = 0.1, y = 0.2 moles. The ceramic composition Bi0.90Yb0.10Ni0.2Fe0.80O3exhibited the minimum optical band gap 1.25 eV, and these particles showed the photocatalytic activity of >64%. The fabricated ceramic inherited magnetic merits and could be easily removed by applying conventional magnetic bar.

BiFeO3(BFO) multiferroics were synthesized via a low-cost wet chemical method. The enigma involved the optimization of different reaction conditions. A comprehensive study was carried out to optimize the reaction conditions such as molar ratios of surfactant with total concentration of precursors, chemical source and solubility of precursors and annealing temperature. A pragmatic nucleation of precursors was achieved at molar proportions 1:1 between cetyltrimethylammonium bromide (CTAB) and total molar concentration of precursors. An endeavor approach was made to accomplish the appropriate flexibility of emulsion phase by adding small quantity of ethanol as a co-surfactant, nevertheless the solubility of Bi(NO3)3/BiCl3was unfavorably affected. Subsequently, the single phase product of BFO was observed with reaction conditions 1:1 molar concentration ratio between precursors and CTAB, with precursors BiCl3and Fe(NO3).9H2O and annealing temperature of 900°C for a time of 7 h. The structural elucidation was made by comparing the extracted data with standard cards (ICDD - 01-086-1518) of XRD. The crystallite size was computed to be 18 nm. The DC conductivity was found to be 1.005 × 10–9S cm–1. The optical band gap was found in the range of ~2.6 eV. Keeping in view the optical band gap, BFO nanoparticles were investigated for photocatalytic degradation of Congo Red dye under visible light. The photocata- lytic degraded sample was investigated through the high-performance liquid chromatography (HPLC) and chemical oxygen demand estimation (COD value) for treated sample was calculated to be 63.27% which is less than the untreated sample which disclosed a photodegradation of Congo Red dye into simple hydrocarbon products as perceived in HPLC–chromatogram. The post XRD data showed the stability of BFO which could be separated through a simple bar magnet from reaction container.