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Summary: The hard/soft CoFe2O4/(NiSc0.03Fe1.97O4)x (0 ≤ x ≤ 5) or simply (CFO‐xNFSO) nanocrystals (NCs) were synthesized through sol–gel auto‐combustion technique. The structural and magnetic properties of the ferrite composite NCs were explored in detail. The synthesized NCs were applied in the fabrication of supercapacitor electrodes to investigate their potential in energy storage applications. The cubic spinel ferrite phase of the NCs was verified by powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), and high‐resolution transmission electron microscopy (HR‐TEM) techniques. The NCs with different x ratios displayed smoothed magnetic hysteresis loops during magnetization at 300 and 10 K temperature. In addition, the plots of switching field distribution (SFD) indicated a single peak in dM/dH vs H plots. These findings demonstrate a good exchange‐coupling in the CFO‐xNFSO (0.0 ≤ x ≤ 5) magnetic NCs. The supercapacitor devices fabricated from the synthesized NCs displayed enhanced capacitance and relatively high energy density as compare to electric double‐layer (EDL) (carbon‐based) supercapacitors. The supercapacitor fabricated from CFO‐xNFSO for x = 2 showed best performance in terms of specific capacitance with 204.4 F g−1 at a scan rate of 10 mV s−1. The performances of the fabricated supercapacitors were further tested for a higher potential window of 1.2 V, where a specific energy value of 33.2 Wh kg−1 is achieved that is 144% enhancement from the same supercapacitor working at 0.8 V and 187% enhancement as compared to the carbon‐based supercapacitor. The device also displayed excellent stability as it was tested for 5000 charge–discharge cycles. [ABSTRACT FROM AUTHOR]

Abstract: The work presented here deals with the photoreduction in metallic silver nanoparticles onto the surface of Ag3PO4 and resulting photocatalytic activity enhancement toward degradation of dye molecules, namely Rhodamine B (Rh. B) as a model compound, from aqueous solution under UV or visible light irradiation. Our results clearly indicated that the photoactivity of Ag3PO4 was significantly enhanced by depositing an optimum amount of silver nanoparticles, even though the adsorption kinetics rate and capacity decreased after the silver nanoparticles agglomerate extensively. The surface plasmon resonance (SPR) excited between the silver nanoparticles and Rh. B interface is a physical origin and responsible for the boosted photoactivity, which strongly depends on the specific wavelength of the incident light. This work provides and suggests a novel scheme for Ag/Ag3PO4 composites having plasmonic effect on the interface with detailed experimental and theoretical study. [Copyright &y& Elsevier]

In this study, the samples of the ZnFe2O4 (ZFO) spinel ferrites nanoparticles (SFNPs), Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4 (CNGaGdFO) SFNPs and (Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4)x/(ZnFe2O4)y (x:y = 1:1, 1:2, 1:3, 2:1, 3:1 and 4:1) (CNGaGdFO)x/(ZFO)y spinel ferrite nanocomposites (NC) have been synthesized by both sol-gel and Green pulsed laser ablation in liquid (PLAL) approaches. All products were characterized by X-ray powder diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), elemental mappings and energy dispersive X-ray spectroscopy (EDX). It was objected to tune the magnetic properties of a soft spinel ferrite material with a softer one by mixing them with different fractions. Some key findings are as follows. M-H investigations revealed the exhibition of ferrimagnetic phases for all synthesized samples (except ZnFe2O4) that were synthesized by sol-gel or PLAL methods at both 300 K and 10 K. ZnFe2O4 ferrite NPs exhibits almost paramagnetic feature at 300 K and glass-like phase at very low temperatures below 19.23 K. At RT analyses, maximum saturation magnetization (MS) of 66.53 emu/g belongs to nanocomposite samples that was synthesized by sol-gel method and x:y ratio of 1:3. At 10 K analyses, MS,max = 118.71 emu/g belongs to same nanocomposite samples with ratio of 1:3. Maximum coercivities are 625 Oe belonging to CNGaGdFO and 3564 Oe belonging to NC sample that was obtained by sol-gel route having the 3:1 ratio. Squareness ratio (SQRs = Mr/MS) of NC sample (sol-gel, 4:1 ratio) is 0.371 as maximum and other samples have much lower values until a minimum of 0.121 (laser, 3:1) assign the multi-domain wall structure for all samples at 300 K. At 10 K data, just CNGaGdFO has 0.495 SQR value assigning single domain nature. The maximum values of effective crystal anisotropy constant (Keff) are 5.92 × 104 Erg/g and 2.4 × 105 Erg/g belonging to CNGaGdFO at 300 K and 10 K, respectively. Further, this sample has an internal anisotropy field Ha of 1953 Oe as largest at 300 K. At 10 K another sample (sol-gel, 3:1 ratio) has Ha,max of 11138 Oe which can also be classified as a soft magnetic material similar to other samples. Briefly, most magnetic parameters of NCs that were synthesized by sol-gel route are stronger than magnetic parameters of the NCs that were synthesized by PLAL at both temperatures. Some NC samples were observed to have stronger magnetic data as compared to magnetic parameters of Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4 NPs at 10 K. [ABSTRACT FROM AUTHOR]

A comparative study has been performed for Laser induced photo-catalytic oxidation/splitting of water into hydrogen and oxygen over Fe2O3, WO3, TiO2 and NiO catalysts under the irradiation of a strong laser beam at 355 nm for the first time. The activity of these catalysts and various electron capture agents such as Fe+3, Ag+, Al+3, and Li+ in the water splitting process was investigated. The yield of hydrogen and oxygen produced was enhanced considerably by the addition of electron capture agents. [Copyright &y& Elsevier]