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Materials such as ternary MIMIIIE2 (where MI = Ag, Cu; MIII = In, Fe; E = S, Se) chalcopyrite-type nanocrystals have garnered interest recently because of their size- and composition-tunable electronic and optical properties. However, controlling the composition of multinary compounds is challenging due to the difference in reactivity of the involved components. Metal–organic precursors usually provide better control over stoichiometry due to preformed bonds. Herein, we have synthesized suitable sulfur-based (dihexyldithiocarbamato) and selenium-based (tetradiphenylimidodiselnodiphosphanate) metal-organic precursors of iron for the preparation of phase pure ternary CuFeS2 and CuFeSe2 nanocrystals, via hot injection route using oleylamine as solvent, decomposition initiator and capping agent. The nanomaterials were characterized by powder-X-ray diffraction (p-XRD), high resolution-transmission electron microscopy (HR-TEM), TEM, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and ultraviolet–visible (UV–Vis) analysis. The effect of temperature on synthesized nanoparticles was also investigated, showing that the size and morphology change from particles to sheet-like structures. The band gap of synthesized nanomaterials also showed variation along with the temperature change. The study shows a facile route for composition and morphologically controlled ternary chalcopyrite nanomaterials. [ABSTRACT FROM AUTHOR]

Iron based nanostructures of iron sulfide (FeS2), iron selenide (FeSe2) and iron sulfo selenide (FeSxSe1-x) have been synthesised by one pot approach, using Fe(III) or Fe(II) chloride as iron source and sulfur or selenium powder as S and Se source in oleylamine. These as-synthesised nanostructures were characterized by X-rays diffraction (XRD), High resolution transmission electron microscopy (HR-TEM) and energy dispersion X-rays (EDX) spectroscopy. The as-prepared nanostructures were also investigated for their performance as photocatalysts for the degradation of a carcinogenic industrial dye RS3B directly under solar light. The detailed HR-TEM investigations show that kinetic factor (reaction time) plays a crucial role in synthesis of nanostructures and with 30 min, much better quality of nanostructures with improved crystallinity, dimensions, yields and electronic properties were obtained as-compered to those synthesized with one hour reaction time. This observation was true for all three materials (FeS2, FeSe2 and FeSSe). [ABSTRACT FROM AUTHOR]

Zinc oxide and copper doped zinc oxide nanoparticles (NPs) were synthesized by the co-precipitation method. The as-synthesized samples were characterized by X-ray diffraction analysis, scanning electron microscopy, Fourier transform infrared, and ultraviolet–visible spectroscopy. The absorption studies have shown the decrease in bandgap with the increase in Cu ion doping from 3, 6, 9, 12, to 15% in ZnO lattices. Furthermore, ZnO and Cu-doped ZnO NPs successfully employed in bulk heterojunction solar cells. The devices constructed with pure ZnO in the P3HT blend showed a power conversion efficiency of 0.1%. Whereas the device fabricated with P3HT-Cu-doped ZnO (Cu, 12%) exhibited the highest power conversion efficiency of 0.31% with open-circuit voltage (Voc) of 0.30 V, short-circuit current density (Jsc) of 2.54 mA/cm2, and fill factor of 41.84%. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is an emerging way for the production of H2, which has the ability to reduce the dependence on fossil fuels for the power generation and provide an ecologically safe storage of solar energy. Fabrication of photoelectrode is one of the major challenges to make PEC water splitting more effective and efficiently sustainable. In this article, we have focussed on the studies of antimony (Sb)-incorporated ZnO photoelectrodes and their evident effects in boosting the PEC water splitting activities using different concentrations of Sb incorporated on fluorine-doped tin oxide (FTO) via aerosol-assisted chemical vapour deposition method (AACVD). The as-deposited photoelectrodes were characterized by using different techniques and were applied for the water splitting. The incorporated thin films exhibited better light absorbance in the visible range, probably because of the generation of extra energy levels through metal incorporation. An enhanced PEC water splitting performance was observed by Sb-incorporated ZnO photoelectrodes as compared to pure ZnO. More specifically, 15% Sb-incorporated ZnO attained a photocurrent density of 0.99 mA cm−2 at 0.85 V vs. Ag/AgCl and maximum photo-stability that is quite greater as compared to pure ZnO (0.19 mA cm−2). This improvement was stated by the reduced bandgap and multifaceted morphological aspects of Sb-incorporated ZnO. In the production of simple and low-cost synthetic methods and effective electrode materials for PEC water splitting applications, these results are proved to be very helpful. [ABSTRACT FROM AUTHOR]

A photoelectrochemical (PEC) water splitting ability of pure ZnO and manganese-incorporated ZnO thin films fabricated via a simple aerosol-assisted chemical vapour deposition (AACVD) method was compared in Na2SO4 electrolyte solution. Optical properties analysis showed the shifting of optical band gap from 3.02 to 2.76 eV as the molar ratio of Mn varies from 0.02 to 0.15. All the compositions of Zn1−xMnxO (x = 0.02 to 0.15) show superior photocurrent density compared to pure ZnO-based photoanodes. The activity of Zn0.85Mn0.15O was found highest with photocurrent density of 3.81 mA/cm2. This activity enhancement was due to the shifting of the optical band gap in the visible region with the increase in absorption intensity. Moreover, the activity is further affected by the growth of uniform and homogeneous structures onto the photoanodes. The morphology of the films and size of crystallites change by varying amounts of Mn into the ZnO films. Overall, this work demonstrates that Zn1−xMnxO has a significant potential for PEC water splitting with further tailoring of their electronic properties. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of Cr incorporated ZnO sheets arrays microstructures and construction of photoelectrode through a direct aerosol assisted chemical vapour deposition (AACVD) method. The as-prepared Cr incorporated ZnO microstructures were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, powdered X-ray spectroscopy, X-ray photoelectron spectroscopy and UV-Vis diffused reflectance spectroscopy. The Cr incorporation in ZnO red shifted the optical band gap of as-prepared photoanodes. The 15% Cr incorporation in ZnO has shown enhanced PEC performance. The AACVD method provides an efficient in situ incorporation approach for the manipulation of morphological aspects, phase purity, and band structure of photoelectrodes for an enhanced PEC performance. [ABSTRACT FROM AUTHOR]

CoFe2O4 nanoparticles (CFO) were synthesized via co-precipitation method and then gold coating (Au@CFO) was carried out by direct reduction of gold salt using citric acid and sodium citrate. Au coating was systematically observed by UV-Vis spectroscopy and afterwards confirmed by scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. Gel electrophoresis was used to check the dispersive stability of Au@CFO dispersion which showed no agglomeration and indicated uniform size distribution. Magnetic characteristics before and after coating were studied via hysteresis loops which indicated reduction in magnetization of CFO after Au coating. Radio frequency (RF) heating measurements were done on powder and dispersed samples to evaluate their magnetic heating. Specific loss power was calculated from RF heating, which was greater for powdered samples than the dispersion of Au@CFO nanoparticles, but temperature can be controlled to reach the therapeutic range with respect to time and concentration. [ABSTRACT FROM AUTHOR]