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In the present investigation, the sol–gel technique was utilized to synthesize pure and Fe3+ doped cerium oxide (CeO2) nanoparticles. The synthesized nanomaterials underwent extensive analytical and spectroscopic characterization process to ascertain their physicochemical properties. The analysis of powder X-ray diffraction (PXRD) patterns revealed that the incorporation of 0.5 M Fe resulted in a decrease of crystallite dimensions to 11 nm, in contrast to the 44 nm observed in the undoped CeO2. Moreover, the introduction of Fe impurities was found to narrow the energy bandgap, evidenced by a decrease from 3.00 eV in pure CeO2 to 2.20 eV in CeO2 doped with 1.5 M Fe, thereby enhancing the material’s optical absorption into the visible light range. An examination of electron density distribution provided insights into the bonding characteristics of the materials post-synthesis. The photocatalytic efficiency of the Fe-doped CeO2 nanoparticles was evaluated through degradation of methyl orange (MO), under the influence of visible light irradiation. Remarkably, the Fe-doped CeO2 nanoparticles exhibited a significant photocatalytic activity, culminating degradation efficiency of 88% of MO within a span of 60 min. This pronounced photocatalytic efficiency underscores the potential application of Fe-doped CeO2 nanoparticles in the domain of environmental cleanup. [ABSTRACT FROM AUTHOR]

In this work, we have fabricated a novel electrochemical biosensor based on TiO2/PS. Heterostructure by sol–gel assisted with spin-casting technique. XRD profile showed the tetragonal phase of TiO2 thin films. SEM images observed the nanoporous-like surface morphology. The film has 78 nm of grain size calculated from AFM analysis. The PL spectrum recorded a strong emission peak at 485 nm, 530 nm, and 545 nm due to blue and green emission. The enhancement of the electrochemical reaction was analysed by cyclic voltammetry (CV). The fabricated electrode has shown the sensitive and stable detection of carbohydrates. The more consistent results showed that TiO2/PS electrode is a promising material for the carbohydrates biosensor. Most importantly, the TiO2/PS electrode achieved a correlation between the coefficient (R2) and sensitivity 0.99 and 26 μA mM−1 cm−2 of glucose. Similarly, 0.98 & 16 μA mM−1 cm−2 for sucrose and 0.96 & 11 μA mM−1 cm−2 for starch. [ABSTRACT FROM AUTHOR]

NiCo2S4 is a promising material for use in supercapacitors due to its high conductivity and redox activity. However, its cycling stability is poor due to the structural degradation of the electrode caused by the redox reaction. NiCo2S4 is encased with an ultrathin graphene oxide layer to produce a core/shell structure (NiCo2S4@GO). We present a simple approach for the fabrication of NiCo2S4/graphene composites. With a specific capacitance of 1100 F g−1 and a current density of 1 A g−1, the NiCo2S4@GO composite demonstrates exceptional electrochemical performance. A hybrid supercapacitor assembled using the synthesized NiCo2S4@GO as a positive electrode and porous carbon as a negative electrode demonstrates a high energy density of 26.9 W h kg−1 at a power density of 658 W kg−1 in the voltage range 0–3.5 V. After 10,000 charge/discharge cycles, the device still retains 78% of its initial capacitance. [ABSTRACT FROM AUTHOR]

Tungsten disulfide (WS2) thin films were deposited on the glass substrate by varying its temperature from 350 to 500 °C using jet nebulizer spray pyrolysis (JNSP) technique. The WS2 thin films were characterized through various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX), UV-Visible spectroscopy (UV), photoluminescence (PL), Hall measurements and current-voltage (I-V) characteristics. XRD pattern revealed that the prepared WS2 films are polycrystalline in nature with rhombohedral and hexagonal crystal structures. The average crystallite size of WS2 thin films changed from 52.23 to 47.40 nm. SEM images showed the uniform grain size, which is agglomerated at the higher substrate temperature. The presence of elements like W and S was confirmed through EDX spectrum. From UV analysis, the minimum optical band gap and maximum absorption was obtained for the film deposited at 450 °C. The WS2 thin films exhibited an n-type semiconductor nature with the carrier concentration of 1014 cm−3, which was demonstrated through hall measurements. Also, the electrical resistivity of the WS2 films varied from 3.26 × 105 to 1.59 × 107 Ω cm. The p-Si/n-WS2 junction diode was fabricated with various substrate temperature of (350-500 °C). Junction diode parameters like ideality factor (n), barrier height (ϕB) and reverse saturation current (Io) values were calculated and interpreted based on the thermionic emission theory model. [ABSTRACT FROM AUTHOR]

Metal–insulator–semiconductor (MIS) structure of Cu/Zr–WOx/p-Si Schottky diodes with different concentrations (0, 4 and 8 wt%) of Zr content were fabricated. The interfacial layer of zirconium–tungsten oxide (Zr–WOx) film was grown on p-type silicon (p-Si) wafer using jet nebulizer spray pyrolysis (JNSP) technique at the substrate temperature of 400 °C. After that, the Cu electrode was coated on the Zr–WOx film via vacuum deposition method. The multiphase (orthorhombic and cubic) crystal structures of Zr–WOx were revealed by X-ray diffraction (XRD) pattern. The surface morphological analysis using scanning electron microscope (SEM) showed the dissimilar structures of surface and energy dispersive X-ray diffraction (EDX) confirmed the presence of W, Zr and O atoms. Using UV–Visible (UV–Vis) and DC elecrical (I–V) analysis, the minimum band gap energy and average conductivity were obtained for higher concentration (8 wt%) of Zr content. The minimum barrier height (ΦB) and minimum ideality factor (n) values were attained for 4 wt% of Cu/Zr–WOx/p-Si Schottky barrier diode (SBD) under illumination condition. [ABSTRACT FROM AUTHOR]