1-(2-Hydr­oxy-5-methyl­phen­yl)ethanone [(1H-indol-3-­yl)acet­yl]hydrazone

The indolyl –NH group of the title Schiff base, C19H19N3O2, forms a hydrogen bond to the –OH group of an inversion-related mol­ecule, resulting in a hydrogen-bonded dimer; adjacent dimers are further linked through an inter­dimer N—H⋯O hydrogen bond involving the –C(=O)–NH–N=fragment to form a linear ribbon that runs along the a axis

Hydrothermal syntheses of tungsten doped TiO 2 and TiO 2 /WO 3 composite using metal oxide precursors for charge storage applications

Synthesis of advanced functional materials through scalable processing routes using greener approaches is essential for process and product sustainability. In this article, syntheses of nanoparticles of titanium dioxide (TiO₂), tungsten trioxide (WO₃), WO₃-doped titanium dioxide (W-TiO₂) and TiO₂/WO₃ composite at hydrothermal conditions using corresponding metal oxide precursors are described. Electrochemical charge storage capabilities of the above materials are measured using cyclic voltammetry, charge-discharge cycling and electrochemical impedance spectroscopy in aqueous KOH electrolyte. The TiO₂ and the WO₃ nanoparticle showed a specific charge (Q) of ∼12 and ∼36 mA h g⁻¹ at a current density of 2 A g⁻¹ in 6 M KOH, respectively. The Q of TiO₂ increased upon W doping up to 25 mA h g−1 for 5 wt% W-TiO2 and the WO₃/TiO₂ composite showed the highest storage capability (Q ∼40 mA h g⁻¹). Changes in the charge storage capabilities of the doped and composite materials have been correlated to materials properties.Bhupender Pal acknowledges the Research & Innovation Department of Universiti Malaysia Pahang (http://ump.edu.my) for award of Postdoctoral Fellowship. This project is funded under Flagship Strategic Leap 3 of Universiti Malaysia Pahang (Grant Number # RDU 172201)

Studies of platinum electrodeposition

Further studies of an electroplating solution consisting of [Pt(NH3)4](HPO4) in aqueous 30 mM Na2HPO4 at pH 10-10.4, known commercially as Q bath, have been carried out. Measurements of the steady state currents as a function of potential for a copper disc electrode in this solution confirm the conclusion from voltammetry at microelectrodes that the rate of reduction of [Pt(NH3)4]2+ to Pt depends strongly on temperature and is not mass transport controlled even at 368 K. Indeed, a temperature above 350 K is essential to see Pt plating at a significant rate. These observations are interpreted in terms of a mechanism involving ligand substitution prior to electron transfer and it is suggested that the electroactive species is [Pt(NH3)4-x(H2O)x]2+. The same experiments show that the rate of Pt deposition passes through a sharp maximum as the potential is made more negative. The decline negative to the peak is attributed to the adsorption of hydrogen atoms onto the Pt surface.Potential step experiments at 368 K show that the deposition of Pt occurs via progressive nucleation and three dimensional growth under electron transfer control. This is also consistent with the surface morphology observed by scanning electron microscopy. In general, several types of growth are identified by SEM. The electroplated layers may appear featureless, show large hemispherical centres, cauliflower growth or a deposit made up of small angular crystallites. Whether plated at constant current or constant potential, the morphology of the deposit is mainly determined by the potential for electrodeposition. The featureless deposits (formed at low constant current) are also highly reflecting but they are always highly stressed and readily crack on cooling from the plating temperature, particularly when thick. The deposit made up of angular crystallites were matt and sometimes black, never cracked and formed at potentials where hydrogen adsorption occurs. The cauliflower deposits were formed at intermediate potentials where the highest rates of deposition were observed. Constant potential deposition had several advantages over constant current deposition; satisfactory deposits could be formed with a fivefold higher rate and thick deposits were much less stressed. The morphology of the deposits is also influenced by the pre-treatment of the copper electrode surfaces.It has been reported that adherent and bright, thick deposits can be formed with high current efficiency only when the bath is operated at &gt; 363 K, an inconveniently high temperature. In fact, although the aret of deposition is lower than at 368 K, it is possible to obtain reasonable electroplates with a good current efficiency at 358 K but it is almost essential to use constant potential deposition in order to obtain a significant rate of deposition. The improved rate of deposition at constant potential arises because of the peaked current-potential characteristic; with constant current deposition, the cathode always takes up a stable potential well to one side of the peak.</p

Electrodeposition of quaternary alloys in the presence of magnetic field

ABSTRACT: Electrodeposition of Ni-Co-Fe-Zn alloys was done in a chloride ion solution with the presence and absence of a Permanent Parallel Magnetic Field (PPMF). The PPMF was applied parallel to the cathode surface. The deposition profile was monitored chronoamperometrically. It was found that the electrodeposition current was enhanced in the presence of PPMF (9 T) compared to without PPMF. The percentage of current enhancement (Gamma%) was increased in the presence of PPMF, with results of Gamma% = 11.9%, 16.7% and 18.5% at -1.1, -1.2 and -1.3 V respectively for a 2400 sec duration. In chronoamperometry, the Composition Reference Line (CRL) for Ni was around 57%, although the nobler metals (i.e. Ni, Co) showed anomalous behaviour in the presence of Zn and Fe. The anomalous behaviour of the Ni-Co-Fe-Zn electrodeposition was shown by the Energy Dispersive X-Ray (EDX) results. From Atomic Force Microscopy (AFM) measurements, it was found that the surface roughness of the Ni-Co-Fe-Zn alloy films decreased in the presence of a PPMF

Super-Amphiphobic Coating System Incorporating Functionalized Nano-Al2O3 in Polyvinylidene Fluoride (PVDF) with Enhanced Corrosion Resistance

Understanding the corrosion inhibition behavior of super-amphiphobic coating is important to ensure practicability in the real application. 2 layers system of super-amphiphobic coating was successfully developed using functionalized nano-Al2O3 incorporated in polyvinylidene fluoride (PVDF). This study investigates the effect of different amount of functionalizing agent on the coating&rsquo;s repellency and its relationship toward the corrosion inhibition behavior. We found that a higher amount of fluoroalkylsilane (FAS) led to a decreased in repellency of both water and oil. Electrochemical impedance spectroscopy (EIS) analysis suggests that the synergetic effect between super-hydrophobicity, longer diffusion path, and barrier effect; enhanced the corrosion resistance. Although the coatings demonstrate similar behavior, the most superhydrophobic/amphiphobic coating C1 offers the highest corrosion protection

Effect of Ce Doping on RGO-TiO2 Nanocomposite for High Photoelectrocatalytic Behavior

Ce doped RGO-TiO2 composite films on ITO substrates were prepared by sol-gel process using tetrabutyl titanate and reduced graphene oxide (RGO) as the starting materials. The sample was designed for the photoelectrocatalytic applications. The obtained samples were characterized by X-ray diffraction, UV-vis absorption spectroscopy, scanning electron microscopy, and Fourier transformed infrared spectroscopy. The results showed that doping of Ce on RGO-TiO2 composite film inhibited the TiO2 anatase-rutile phase transformation. In this case, Ce atoms could serve as dispersion oxide and suppress the recombination of photoinduced electron-hole pairs. Besides, the change in absorbance from UV to visible region was observed in Ce doped RGO-TiO2 nanocomposite films. The Ce doped RGO-TiO2 composite film showed higher photoelectrochemical performance than that of RGO-TiO2 composite and pure TiO2 under solar simulator irradiation. The main reason might be attributed to the optimum content of Ce that could act as electrons acceptor to hinder the recombination loss and facilitate the better transportation for photoinduced charge carriers