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The 3D NiMoxCo2–xO4 (x ≤ 0.06) chestnut-like spinel oxide nanoparticles (CNSPs) grown on Ni foam were effectively prepared hydrothermally. The formation of Ni–Co CNSPs was confirmed by the XRD powder pattern, which exhibited a pure cubic spinel oxide structure without undesired phases. All ratios revealed a broadened peak representing a small crystal size (12.8–17.5 nm) range. The chestnut-like CNSPs were presented by FE-SEM, SEM, TEM, and HR-TEM analysis. The chemical composition of the products was confirmed by EDX. The 3D NiMoxCo2–xO4 (x = 0.04) CNSP electrocatalyst exhibited hydrogen evolution reaction (HER) activity as evidenced by 0.224 V overpotential, Tafel slope 61.9 mV/dec, and high stability for 36 h of chronopotentiometry techniques. The surface and electrochemical characterization revealed that 4.0% Mo-doped exhibits improved HER activity due to significantly higher electrochemical surface area and accelerated charge-transfer kinetics at the semiconductor electrolyte interface. Density functional theory is employed to investigate the impact of Mo dopants on the HER performance. This study shows how both hydrogen and water molecules adhere to the surface of Mo-doped NiCo2O4 slab structures. The findings indicate that introducing Mo dopants leads to an augmentation of chemical activity through water adsorption, resulting in an enhanced electrocatalytic process and improved HER activity up to a specific Mo concentration, and their impact on spin-dependent electronic structure characteristics is revealed by the density of states spectra. This work not only gives insights into low-metal-cost materials for efficient and durable HER electrocatalysts, but it also provides a successful showcase model catalyst for in-depth mechanistic insights into electrochemical HER processes and their industrial applications in the future. [ABSTRACT FROM AUTHOR]

It is indispensable to accurately and sensitively identify and analyze the elemental composition of human blood serum. In the current study, human blood serums were analyzed for elements utilizing orthogonal dual pulse laser-induced breakdown spectroscopy (DP-LIBS) setup in He gas environment. Experimentally, a fundamental pulse Nd:YAG laser (1064 nm, 7 ns) was irradiated just above the material target to induce a luminous gas plasma. A third harmonic pulse Nd:YAG laser (355 nm, 7 ns) was subsequently focused on the material surface to initiate a target plasma to ablate the atoms from the blood serum film to be sent to the gas plasma region. Double pulse LIBS technique has been successfully applied to increase the LIBS signal intensity up to 8 folds of major, minor, and trace components in human blood serum. Furthermore, a number of emission lines that were indistinctly detected by single pulse LIBS were accurately identified with the use of the DP-LIBS. A variety of components from the human blood serum have been analyzed both qualitatively and quantitatively. Element concentrations measured in human blood are to be 8360 ppm, 219 ppm, 581 ppm, 785 ppm, 343 ppm, 293 ppm, and 12 ppm for C, Ca, K, Mg, P, Na, and Fe, respectively. The LIBS outcome results are in excellent agreement with the results acquired by applying the standard XRF technique. [ABSTRACT FROM AUTHOR]

Summary: The photoanode of the conventional dye‐sensitized solar cell (DSSC) is modified, by depositing a layer of cobalt‐metallic‐ion‐coordinated metal–organic framework (Co‐MOF199) on top of the regular titanium‐dioxide film. The results of electrochemical impedance spectrum (EIS) indicated that the presence of Co‐MOF199 layer in the photoanode of DSSC brought about an increase in the electron recombination lifetime (time to the electrons to recombine with the cations) and, consequently, the increase in electron recombination resistance (Rrec) in the photoanode electrolyte interface. The increased recombination resistance is attributed to the efficient retardation of the rapid recombination between photo‐induced electrons and transient cations in DSSC. These positive changes in the photoanode electrolyte interface of DSSC resulted in the increase in open‐circuit voltage (Voc), which accounts for the ultimate 20% enhancement in the power conversion efficiencyη, compared to the conventional DSSC. A total of six Co‐MOF199 concentration variants of DSSC configurations coated by soaking and spin coating were fabricated, and it was observed that [TiO2 + N3/Co‐MOF199 (30 mM)/Pt] DSSC configuration (soaked), in particular, exhibits the best photovoltaic parameters with Voc ~ 827 mV, Rrec ~ 170 Ω, and η ~ 8.38%, compared to the conventional DSSC, where Voc ~ 758 mV, Rrec ~ 76 Ω, and η ~ 6.91%. In addition to photovoltaic characterizations, morphological, elemental, and crystallographic characterizations of the Co‐MOF199‐coated photoanodes were carried out. [ABSTRACT FROM AUTHOR]

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]

Herein, photocurrent generating a millimeter‐scale bioelectrochemical cell (mBEC) is fabricated using a thylakoid membrane (TM) on a screen‐printed electrode (SPE). The mBEC is used to generate a direct and mediated photocurrent without using a selective membrane. The mediated photocurrent generation is tested with iron oxide nanoparticles (NPs) coated on the SPE surface and the water soluble mediators potassium hexacyanoferrate (FCN) and p‐Benzoquinone (BQ). The SPE/TM system produces a 4.35 μA cm−2 photocurrent without using a mediator obtained by direct electron transfer (DET). A significant enhancement reaches the current generation when an efficient amount of mediator is used in the system. The SPE/NP/BQ/TM system produces a 55 μA cm−2 photocurrent with an incorporation among TM, NP, and BQ. The performance of the mBECs is tested by taking the measurements from series and parallel connected cells. An enhanced photocurrent generation of 178 μA cm−2 is attained when the four cells are connected in series. Also, a higher light conversion rate is achieved by the parallel connected two cells. In addition, the maximum current density of mBEC obtained from the SPE/NP/BQ/TM cell at a pseudo‐steady state is 180 mA m−2 at a power density of 40 mWm−2. [ABSTRACT FROM AUTHOR]

A synthesis of aminothiazoles from various 1,3-dicarbonyls and thioureas without a leaving group has been developed. The reaction is photocatalyzed by tetraiodofluorescein, an organic dye. Under irradiation with green LEDs, a sulfur radical is generated in situ from thiourea, followed by addition to the enol tautomer, forming the aminothiazole backbone. This novel strategy provides a greener alternative to the traditional leaving group protocols, with excellent atom economy. [ABSTRACT FROM AUTHOR]

Narrow band gap semiconductors like cadmium sulfide (CdS) are being applied as an agent to reduce the band gap of metal oxide semiconductors like titanium dioxide (TiO2). In order to obtain a TiO2/CdS nanocomposite with reduced electron-hole recombination and improved stability, we coupled 10%, 20%, and 40% by weight of CdS with TiO2 in this work using pulsed laser ablation in liquid technique. Here, 532 nm wavelength generated from neodymium-doped yttrium aluminum garnet laser was directed into the TiO2/CdS mixture prepared in a colloid form to produce the TiO2/CdS nanocomposites. The effect of the CdS concentration on the performance of the obtained nanocomposite in a dye-sensitized solar cell and photocatalytic degradation of methyl orange in water was studied in detail. However, the nanocomposite with 10% percentage weight of CdS in anatase TiO2 showed the best performance as compared with pure TiO2, and the photoconversion efficiency of the dye-sensitized solar cell was improved from 0.6% to 4.3%, while the percentage of methyl orange degraded was enhanced from 58% to 82% after 36 min irradiation using ultraviolet-visible light. This improvement in photovoltaic and photodegradation properties is due to limited electron hole recombination rate, higher conduction of charge carriers, their longer lifetime during the photocatalytic process, improved ultraviolet-visible light activity, reduced photocorrosion, and improved pore size. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this work we report the synthesis of an electrically conductive polypyrrole–titanium(iv)phosphate (PPy–TiP) nanocomposite using simple, facile in situ chemical oxidative polymerization of polypyrrole (PPy) in the presence of titanium(iv)phosphate (TiP) for immobilization of the yeast alcohol dehydrogenase enzyme. FTIR, FE-SEM and TGA were employed for the characterization of PPy, TiP and the PPy–TiP nanocomposite. YADH was successfully immobilized on the PPy–TiP nanocomposite with a loading efficiency of 69%. The immobilized YADH showed no change in the pH optima (pH 8.0) and there was a broadening of the peak both at acidic as well as in alkaline pH. The optimum temperature of immobilized YADH was increased by 5 °C with almost the same residual activity. Immobilized YADH showed improved thermal stability at 60 °C and retained about 71% activity after 5 h of incubation. Also, the immobilized YADH showed greater reusability and retained 75% activity after 10th successive use. All the results were compared to those of free YADH, immobilized YADH on PPy and immobilized YADH on TiP. The affinity of immobilized YADH for ethanol was decreased as evident from the Km value (223.71 mM) and also there was a decrease in the maximum velocity (201.53 μM min−1) as compared to soluble YADH. The improved residual activity, stability and reusability of YADH immobilized on the PPy–TiP nanocomposite make the enzyme more suitable for industry-based applications. Molecular docking was used to query the protein – the newly synthesized chemical entity interactions that help in understanding the affinity in enzyme activity. [ABSTRACT FROM AUTHOR]

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]

Transparent and amorphous yttrium (Y)/Sialon thin films were successfully fabricated using pulsed laser deposition (PLD). The thin films were fabricated in three steps. First, Y/Sialon target was synthesized using spark plasma sintering technique at 1500 °C in an inert atmosphere. Second, the surface of the fabricated target was cleaned by grinding and polishing to remove any contamination, such as graphite and characterized. Finally, thin films were grown using PLD in an inert atmosphere at various substrate temperatures (RT to 500 °C). While the X-ray diffractometer (XRD) analysis revealed that the Y/Sialon target has β phase, the XRD of the fabricated films showed no diffraction peaks and thus confirming the amorphous nature of fabricated thin films. XRD analysis displayed that the fabricated thin films were amorphous while the transparency, measured by UV-vis spectroscopy, of the films, decreased with increasing substrate temperature, which was attributed to a change in film thickness with deposition temperature. X-ray photoelectron spectroscopy (XPS) results suggested that the synthesized Y/Sialon thin films are nearly homogenous and contained all target's elements. A scratch test revealed that both 300 and 500 °C coatings possess the tough and robust nature of the film, which can resist much harsh loads and shocks. These results pave the way to fabricate different Sialon doped materials for numerous applications. [ABSTRACT FROM AUTHOR]