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• Direct dual Z-scheme TiO-WO 3 -CeO 2 heterostructured nanocomposite successfully synthesized by co-precipitation route. • The nanocomposite TiO-WO 3 -CeO 2 showed boosted photocatalytic activity towards different pollutants. • Systematic investigations confirmed the superior charge separation by direct dual Z-scheme. • Enhanced antibacterial activity of nanocomposite against various pathogenic bacterial strain. • The higher super-capacitive behaviour of nanocomposite. [Display omitted] Direct dual Z-scheme heterostructured nanocomposite TiO 2 -WO 3 -CeO 2 (NC) and pristine metal oxides nanostructures (NSs) were fabricated using a facile co-precipitation route. XRD, FTIR, and Raman data have confirmed the formation of NSs and NC. FESEM images showed quasi-mesoporous morphology of as-grown nanocomposite. EDX analysis confirmed the existence of titanium (Ti), cerium (Ce), and tungsten (W) in grown NC. The energy bandgap of NC was narrow 2.45 eV as compared to NSs. The higher electrical conductivity and lower recombination rate of NC were observed in IV and PL analysis. The photodegradation efficiency of NC was recorded 99.8% after 60 min under sunlight radiation against methylene blue (MB), which was significantly higher than NSs. NC catalyst has shown excellent photodegradation against other organic pollutants and has superior recyclability up to 7th cycle toward MB dye with a ~ 6% deficit in photodegradation efficiency. The antimicrobial activity results indicated the higher inhibition ability of NC against E. coli , K. pneumoniae , S. aureus , P. Vulgaris , and P. aeruginosa with maximum inhibition zone diameter 25, 29, 26, 28, and 27 mm, respectively. The electrochemical tests including CV, EIS, and GCD exhibited the superior capacitive behaviour of NC. These results demonstrate that grown NC is an efficient material for electrochemical devices, water purification, and biomedical applications. [ABSTRACT FROM AUTHOR]

Pristine CdO and chromium (Cr)-cobalt (Co) co-doped CdO nanowires via a facile co-precipitation protocol were synthesized and characterized with different analytical techniques to investigate its physical, photocatalytic, antibacterial, and electrochemical properties. The co-doping of Cr-Co into CdO matrix and their structural variations were confirmed by X-ray diffraction (XRD) data. Fourier transform infrared (FTIR) and Raman spectra also confirmed the doping of Cr and Co ions. The energy bandgap was extracted by employing different methods using UV–vis results, exhibited redshift by decreasing Co contents and blue shift by increasing Cr concentration. Scanning electron microscopy (SEM) images confirmed the preparation of nanowires. The photocatalytic and antibacterial experiments results showed the higher photodegradation efficiency against methylene blue (MB) (99.5%), methyl orange (MO) (90.6%), rhodamine-B (RhB) (87.5%), safranin-O (SF) (87.5%), and methyl red (MR) dyes (99.99%), after 60 min of sunlight illumination and the higher zone of inhibition (ZOI) against Klebsiella pneumoniae and Staphylococcus aureus for optimal doped Cd 0.90 Co 0.05 Cr 0.05 O (Cd4) sample. The recyclability tests using Cd4 catalyst were exhibited higher stability up to 5th cycles. The higher ability to decompose dyes and kill bacteria is due to the generation of reactive species, confirmed by the radical trapping experiments. The electrochemical measurements were revealed that the Cd4 sample has a higher specific capacitance of 500 F/ g− 1 at 10 mV/s scan rate, excellent energy density 72 Wh/Kg, and greater power density of 4800 W kg− 1 at a current density of 0.1 A/g. Furthermore, the properties of CdO can be tuned by co-doping for making it a useful material for photocatalyst, supercapacitors electrodes, and antibacterial applications. [Display omitted] • Pristine CdO and Cr-Co co-doped CdO nanowires were synthesized via a facile co-precipitation method. • Different analytical techniques such as XRD, FTIR, Raman, UV–vis, IV, SEM, CV, EIS, and GCD were used. • Enhanced photocatalytic performance against various pollutants with stability upto 5th cycle was achieved. • Improved antibacterial characteristics against different human pathogenic bacterial strain was attained. • The higher specific capacitance, energy density, and power density at optimal loading of Cr and Co were obtained. [ABSTRACT FROM AUTHOR]

Abstract This paper reports the divalent Ni2+ transition element substituted R-type hexagonal ferrites Sr 1-x Mn 2 Ni x Fe 4 O 11 with composition (x = 0, 0.1, 0.2, 0.3) synthesized by sol-gel auto combustion technique. The XRD patterns for all the samples show single phase characteristics. The XRD data was used to calculate the lattice constant a (Å), c (Å), unit cell volume V (Å)3, crystallite size S(nm) and dislocation density D (1/S2). The lattice parameters decreased as the concentration is increased. The range of crystallite size was 11 nm-13 nm. In high density recording media, this small size is proper to obtain the appropriate signal to noise ratio. The observed room temperature (RT) DC electrical resistivity decreased as Ni+2 substitution increased. The conductivity in voltage range of −200 to 200 has been increased. The trend of dielectric constants and dielectric loss factor enhanced with Ni substitution which was due to surface charge polarization. AC conductivity has been enhanced with frequency. In present synthesized material, the conduction process of the material is demonstrated by Cole-Cole graphs which show one semi-circle that influence the grain boundaries. As the Ni+2 concentration is increased the polarization also increased. The increase in dielectric parameters of the synthesized samples with substituents suggests their importance for high frequency applications. Graphical abstract Typical room temperature P-E relationships of the Sr 1-x Mn 2 Ni x Fe 4 O 11 R-type hexagonal ferrites. Image 1 Highlights • A series of R-type hexagonal ferrites were prepared by Sol-Gel auto combustion method. • The XRD analysis showed that the R-type hexagonal structure. • The electrical resistivity decreases with Ni2+ substitution. • The dielectric properties enhances with the increase of Ni contents. • The cole-cole plot shows the role of grain, grain boundary, and grain and grain boundary. [ABSTRACT FROM AUTHOR]

Fe 3 O 4 could be a better choice as anode for sodium-ion batteries (NIBs) due to high sodium ion storage capability and abundant resource. Yet, the low conductivity and severe volume expansion during cycling have fetched large defies towards practicality. In this work, an ovoid Fe 3 O 4 /rGO and (5%, 10%) cobalt doped Fe 3 O 4 /rGO nanocomposites were synthesized through one-step hydrothermal route. Structural, morphological chemical, vibrational, and compositional analysis have been employed using X-ray diffraction, Scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results indicate the successful substitution of cationic Co2+ ions in Fe 3 O 4 lattice. Hence, integration of optimal cobalt doping in Fe 3 O 4 lattice can alter the charge/discharge specific capacity as compared to undoped Fe 3 O 4 -rGO anode. Due to sufficient production of oxygen vacancies in the structure 5% Co- Fe 3 O 4 /rGO reveals the highest initial charge capacity of 434 mAh g−1 at 0.05 C and exhibits stable prolonged cycling and delivers upto 303 mAh g−1 of charge capacity during 100 cycles (with 100% of CE and 72% of remaining capacity retention)as compared to 10% Co- Fe 3 O 4 /rGO (414 mAh g−1) and Fe 3 O 4 /rGO (357 mAh g−1) nanocomposite. Moreover, the Nyquist plot reveals the rapid transfer of charge for 5% Co- Fe 3 O 4 /rGO anode due to lowest charge transfer impedance of 56.5 Ω as compared to 10% Co- Fe 3 O 4 /rGO (114.3 Ω) and pristine Fe 3 O 4 /rGO (177.8 Ω). Therefore, the presence of rGO layers and the optimum doping of Co atoms in Fe 3 O 4 crystal can curtail volume expansion, generate more contact sites for electrode/electrolyte, deep penetration of electrolyte into the electrode and can yield superior electrochemical performance via fast Na-ion diffusion rate. Sodium-ion batteries are a promising technology for electric vehicles, the energy grid and other applications. [Display omitted] • Fe 3 O 4 /rGO and (5%, 10%) cobalt doped Fe 3 O 4 /rGO nanocomposites were synthesized through one-step hydrothermal route. • The XRD and XPS results indicate the successful substitution of cationic Co2+ ions in Fe 3 O 4 lattice. • 5% Co- Fe 3 O 4 /rGO reveals the highest initial charge capacity of 434 mAh g−1 at 0.05 C. • The high performance of 5% Co- Fe 3 O 4 /rGO anode was attributed to lowest charge transfer impedance of 56.5 Ω. • The presence of rGO layers and the optimum doping of Co atoms in Fe 3 O 4 crystal can curtail volume expansion. [ABSTRACT FROM AUTHOR]

The Ti/CeO 2 /Al/CeO 2 /Pt stacks as a ReRAM device exhibits bipolar and unipolar resistive switching behaviors. The OFF/ON resistance ratio (>10 2 ) in both modes is almost similar but operating voltages are slightly smaller in the former than in the later. These devices could switch between the two operating modes merely by choosing the polarity of RESET voltage. In addition, the requirement of identical current compliance during the SET process of both modes provides an additional advantage of simplicity in device operation. The conduction mechanisms of high resistance state and low resistance state are Schottky emission and Ohmic conduction. On the basis of analyses of current–voltage characteristics and temperature dependence of resistance, resistive switching mechanism originated from a combined effect of field induced diffusion of oxygen and Al ions in the sandwiched ceria matrix. [ABSTRACT FROM AUTHOR]

Abstract: A low temperature chemical approach which beats the miscibility barrier of Fe and Mg has been designed to synthesize Fe–Mg2 nanoalloy and tested to result nanoparticles of average 30nm size. The nanoalloy is amorphous in nature and characterized by XPRD, AFM, magnetometery, Mössbauer and impedance spectroscopies. The result of magnetic measurement suggests the sample to be superparamagnetic as evidenced by the 57Fe Mössbauer spectroscopy. The two Mg atoms occupy different positions around iron resulting in two phase system as shown by Mössbauer and impedance spectroscopies. [Copyright &y& Elsevier]