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Porous nanomaterials with superior peroxidase mimetic activity (nanozyme) at room temperature have gained increasing attention as potential alternatives to natural peroxidase enzymes. Herein, we report the application of porous iron oxide nanoflakes (IONFs), synthesized using the combination of solvothermal method and high‐temperature calcination as peroxidase nanozyme for the oxidation of 3,3′,5,5′‐tetramethylbenzidine (TMB) in the presence of H2O2. The four IONF catalysts possess porous structures with a wide pore size distribution between 2–30 nm and high specific surface areas around to 200 m2 g−1. The increase of calcination temperature of the IONFs from 250 °C to 400 °C resulted in a gradual decrease in their specific surface area and Michaelis‐Menten constant (Km) for TMB oxidation. The optimum IONF sample showed a much lower Km at 0.24 mM (towards TMB) compared to natural enzyme horseradish peroxidase (HRP) at 0.434 mM, revealing the promising potential of the as‐prepared IONFs as alternatives to HRP for biosensing applications. Porous iron oxide nanoflakes show high peroxidase mimetic activity towards the oxidation of TMB at room temperature compared to natural enzyme horseradish peroxidase. [ABSTRACT FROM AUTHOR]

It is shown that the nanostructures of vanadium pentoxide (VO) obtained by laser treatment of films grown by thermal evaporation differ significantly in their properties from analogues based on VO. Results of XRD and SEM studies show the increase in grain size with the increasing intensity of the laser radiation, and spectral analysis data indicate a decrease in the band gap. [ABSTRACT FROM AUTHOR]

TiO thin film has been widely used as photoelectrode in dye-sensitized solar cells. It can also be used in quantum dot synthesized solar cells. Study of its effects in different spectrum of light is important for its use in solar cells. We have reported effects of 1064 nm laser on the surface morphology, structural and optical properties of nanostructured TiO thin film deposited on glass substrates using sol-gel spin coating technique. Q-Switched Nd:YAG pulsed laser at various power densities is used in this study. Surface morphology of the film is investigated using X-ray diffraction (XRD) and atomic force microscopy technique. The XRD pattern of as deposited TiO thin film is amorphous and after laser exposure it became TiO anatase structure. Atomic force microscopy of the crystalline TiO thin film shows that the grain size increases by increasing laser power density. The calculations of the band gap are carried out from UV/Visible spectroscopy measurements with JASCO spectrometer. For laser power density of 25 MW/cm there is an increase in the transmission and it decreases at the value of 38 MW/cm and band gap decreases with increasing laser power density. Photoluminescence spectra of the crystalline TiO thin film indicate two broad peaks in the range of 415 and 463 nm, one for band gap peak (415 nm) and other for oxygen defect during film deposition process. [ABSTRACT FROM AUTHOR]

We have designed solar cells based on nanostructured titanium dioxide sensitized by fluorescein sodium salt, and we have studied their photovoltaic and impedance characteristics. Under AM1.5 illumination and optimal conditions, an open-circuit photovoltage of 0.56 V and a short-circuit current density of 72 μA/cm were achieved. An impedance spectroscopy study of the voltage dependence of the capacitance in the frequency range 2-5 kHz did not reveal any shift from positive to negative capacitance. [ABSTRACT FROM AUTHOR]

Abstract: The electrical and photosensing properties of the p-Si/1,4-DAAQ inorganic–organic diode have been investigated. The diode exhibits a non-ideal behavior with ideality factor of 2.03 and barrier height of 0.85eV. The photovoltaic parameters, open circuit voltage, V oc and short circuit current, I sc of Al/p-Si/1,4-DAAQ diode under AM1.5 were found to be V oc =0.365V and I sc =127μA, respectively. The interface state density of the diode can be controlled by the illumination. The ratio values of C photo/C dark under 10kHz, 100kHz and 500kHz spot frequencies were found to be 3.73, 3.33, 1.70 and 1.02, respectively and the C photo/C dark values decrease with increasing frequency. The obtained results indicate that the photocapacitance properties of the Al/p-Si/1,4-DAAQ diode can be controlled by frequency. It is evaluated that this device can be used a photosensor controlled frequency. [ABSTRACT FROM AUTHOR]