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Transition metal nitrides (TMN) are promising material alternative to replace noble metals in the field of plasmonic applications, especially surface‐enhanced Raman spectroscopy (SERS). Here we demonstrate a practical surface enhanced Raman spectroscopy (SERS) substrate using zirconium nitride (ZrN) thin films grown by reactive gas‐timing (RGT) rf magnetron sputtering. The tailored properties of ZrN thin film exploited for SERS activity could be achieved to obtain a highly sensitive ZrN thin film SERS substrate with the enhancement factor (EF) of 1.24 × 106 and 4.8 %RSD at 1626 cm‐1 toward methylene blue (MB) analyte which are comparable to the optimized Au sputtered thin films (EF=1.18 × 106 and with 5.1%RSD). We find that the spatial plasmonic hotspots on the surface of ZrN SERS substrate controlled by the turn‐on timing of Ar:N2 sputtered gas sequence, leading to the discrete conductive surface profile, strongly relates to non‐stoichiometric composition and the degree of (200)‐oriented texture at the surface of ZrN thin film. Furthermore, ZrN thin film SERS substrates exhibit an excellent recyclability more than 30 cycles with simple cleaning process and a storage time longer than 6 months. The detection and reusability of ZrN SERS substrate on the low concentration of trinitrotoluene (TNT) for homeland security are also performed. [ABSTRACT FROM AUTHOR]

The structural and optical characterizations of nanocomposite films of polymethyl methacrylate (PMMA) and SiO2/TiO2 composites prepared via the spin-coating technique were investigated using different SiO2:TiO2 ratios. The SiO2/TiO2 nanocomposites were synthesized using the sonochemical process with Si:Ti precursor ratios of 1:0.1, 1:0.5, 1:1, 1:2, 1:4, and 0:1. All characterizations of ultrafine SiO2/TiO2 particles were loaded at 1 wt.% in a PMMA matrix for the fabrication of transparent SiO2/TiO2/PMMA composite films. The phase structure and morphology of SiO2/TiO2/PMMA composite films were monitored using X-ray diffraction, optical microscopy, and field-emission scanning electron microscopy. A surface roughness analysis of SiO2/TiO2/PMMA nanocomposite films was conducted using atomic force microscopy. For optical characterization, transmission properties with different incident angles of SiO2/TiO2/PMMA composite films were analyzed with UV-vis spectrophotometry. The water contact angles of SiO2/TiO2/PMMA composite films were analyzed to identify hydrophilic properties on film surfaces. Photocatalytic reactions in SiO2TiO2 composite films under UV irradiation were evaluated using rhodamine B dye degradation. The optimal condition of SiO2/TiO2/PMMA nanocomposite films was obtained at a 1:1 SiO2:TiO2 ratio in self-cleaning applications, resulting from good particle dispersion and the presence of the TiO2 phase in the composite. [ABSTRACT FROM AUTHOR]

We report the application of a coordination polymer semiconductor, tin(II) thiocyanate [Sn(SCN)2], as an ultrathin anode interlayer in organic photovoltaics (OPVs). Sub-10 nm layers of Sn(SCN)2 with high smoothness and excellent transparency having an optical bandgap of 3.9 eV were deposited from an alcohol-based solution at room temperature without post-deposition annealing. Inserting Sn(SCN)2 as an anode interlayer in polymer:fullerene OPVs drastically reduces the recombination loss due to the exciton-blocking energy levels of Sn(SCN)2. At the optimum thickness of 7 nm, an average power conversion efficiency (PCE) of 7.6% and a maximum of 8.1% were obtained. The simple processability using common solvents gives Sn(SCN)2 a distinct advantage over the more well-known copper(I) thiocyanate (CuSCN). The electronic and optical properties of Sn(SCN)2 make it interesting for applications in large-area electronic devices. [ABSTRACT FROM AUTHOR]

Poly(N‐isopropylacrylamide‐co‐acrylamide) (PNIAM‐co‐AM) grafted onto tissue culture polystyrene surfaces (TCPSs) with different thicknesses and grafting densities were prepared by varying the spin‐coating speed and UV irradiation time for use in cell sheet engineering. The thickness of the PNIAM grafted surface, less than 30 nm, was believed to influence protein adhesion and cell attachment. However, methods for determining the thicknesses of a thin surface (nanometer scale) are still a challenge. In this study, a model was developed to relate the thickness of the PNIAM‐co‐AM film to its grafting density. Spectroscopic ellipsometry (SE) and attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR) with synchrotron radiation were used to quantify the thickness and the grafting density, respectively. The amount of the grafted copolymer was determined from quantitative ATR‐FTIR by relating the signals at wavenumber 1,654 to 1,600 cm−1 (A1,654/A1,600) to the known grafting density. A combination of SE and ATR‐FTIR was used to construct a linear model (h = 6.29σ + 2.24), to obtain the grafting density (σ) from the film thickness (h) with R2 = 0.93. To validate the model, random samples were prepared with different thicknesses and grafting densities. The linear model was used to predict the grafting density, which was nearly equal to the measured values. [ABSTRACT FROM AUTHOR]

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Herein, a localized surface plasmon resonance‐based sensor for volatile organic compounds (VOCs) detection is developed. The sensors are fabricated as a hybrid nanostructure of gold nanoparticles coated with a tantalum oxide (TaO) thin film on a glass slide substrate through magnetron sputtering and thermal solid‐state dewetting techniques. The thickness of the TaO film varies between 10 and 70 nm. The optical properties of samples are characterized by UV‐Vis‐NIR spectrophotometry, while their morphologies are confirmed via transmission electron microscopy. The results show the shift of the minimum optical transmittance related to the TaO thickness. Electrical field simulations are performed to predict the sensitivity of the prepared samples for VOCs detection. In addition, the sensors are tested with different VOCs, including formaldehyde, isopropanol, acetone, and methanol, which show good potential for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ni-doped WO 3 nanorod films were fabricated by reactive magnetron co-sputtering with GLAD technique. • GIXRD investigation revealed crystalline of annealed Ni-doped WO 3 nanorod film at 500 °C. • The local structural transformation was studied by a combination of XAS and DFT calculation. • Annealed Ni doped WO 3 nanorod photoanode at 400 °C presents an improving. • PEC performance. Ni-doped WO 3 nanorod films were fabricated via a reactive magnetron cosputtering with a glancing angle deposition technique. The crystal structure and surface morphology were observed using grazing incident X-ray diffraction and field emission Scanning Electron Microscopy, respectively. The chemical compositions and oxidation state of each element were investigated by X-ray photoemission spectroscopy. The local structure and phase evolution were investigated via X-ray absorption spectroscopy. The local structure of Ni atoms in WO 3 nanorod films is characterized as a NiWO 4 nanocluster in the WO 3 matrix, which is supported by calculated spectra. The phase information obtained after annealing demonstrates that short-length order in amorphous transitions to crystallinity. The phase information of the local structures were acquired and discussed as well as the effect on the annealing process. The coupling of amorphous WO 3 , crystalline WO 3 , and amorphous NiWO 4 exhibits high photoelectrochemical activity of the sample annealed at 400 °C, which was observed with a large current density (2.35 μA/cm2) at 1.20 V vs. Ag/AgCl under visible light irradiation, which is greater than that of the unmodified WO 3 photoelectrode (1.38 μA/cm2). [ABSTRACT FROM AUTHOR]