Quality Enhancement of Mustard Oil by Tocotrienol Rich Fraction from Rice Bran Oil

An inexpensive natural antioxidant, tocotrienol rich fraction, prepared from crude rice bran oil, was developed for enriching the quality of mustard oil. DPPH assay of tocotrienol rich fraction showed that it possesses high antioxidant potential. Efficacy of tocotrienol rich fraction in retarding lipid peroxidation was studied by comparing acid value, iodine value, peroxide value, TBARS value, and fatty acid composition of crude mustard oil with and without TRF, stored under accelerated oxidation conditions, such as exposure to elevated temperature of 60°C, aerial oxygen, and UV radiation. The enhanced peroxidation under accelerated oxidation conditions was found to be retarded by tocotrienol rich fraction addition, thereby it increased the shelf life of the mustard oil by decelerating the process of lipid peroxidation.     

Ni-doped TiO2 hollow spheres as electrocatalysts in water electrolysis for hydrogen and oxygen production

This work represented the electrocatalytic properties of Ni-doped titania hollow sphere materials in hydrogen and oxygen evolution during water electrolysis from acidic media. Titania hollow sphere particles were synthesized using poly(styrene-methacrylic acid) latex as template material, and various amount of nickel were doped over the sphere using nickel (II) sulfate as the precursor of nickel. The presence of rutile TiO₂ and NiO phases were revealed during XRD analysis, indicating the critical growth of nickel on the surface of the hollow sphere catalysts. BET surface area results also shown the 166.76 m² g^?1 value for 30 wt% Ni/TiO₂ hollow sphere sample. The SEM and TEM images were confirmed the hollow sphere structure of the catalysts with diameter of 0.8–0.9 μm. The cyclic voltammetric studies proved the presence of both hydrogen and oxygen evolution peaks for all the hollow sphere samples. The anodic peak current density value, which usually represents the oxygen evolution phenomenon, was revealed as 13 mA cm^?2 for 25 wt% Ni-loaded sample; whereas, the hydrogen evolution peak was most intense for 30 wt% Ni/TiO₂ material with cathodic peak current density of 32 mA cm^?2. The average value of ?1.42 were determined as the reaction order of the system irrespective of the nickel loading and heating duration in the synthesis of hollow sphere materials. During photocatalytic water splitting, 30 wt% Ni/TiO₂ hollow sphere sample yielded the highest amount of hydrogen in all irradiation time span.     

Electrochemical performance of Ni/TiO2 hollow sphere in proton exchange membrane water electrolyzers system

This work presents the electrocatalytic evaluation of Ni/TiO₂ hollow sphere materials in PEM water electrolysis cell. All the electrocatalysts have shown remarkably enhanced electrocatalytic properties in comparison with their performance in aqueous electrolysis cell. According to cyclic voltammetric results, 0.36 A cm^?2 peak current density has been exhibited in hydrogen evolution reaction (HER) from 30 wt% Ni/TiO₂ electrocatalyst. 15 wt% Ni-doped titania sample has shown the best result in oxygen evolution reaction (OER) with the anodic peak current density of 0.3 A cm^?2. In the anodic polarization curves, the performance of 15 wt% Ni/TiO₂ hollow sphere electrocatalyst was evaluated up to 140 mA cm^?2 at comparatively lower over-potential value. 20 wt% Ni/TiO₂ hollow sphere electrocatalyst has also shown electrochemical stability in PEM water electrolyzer for 48 h long analysis. The comparative electrocatalytic behavior of hollow spherical materials with non-sphericals is also presented, which clearly shows the influence of hollow spherical structure in greater electrocatalytic activity of the materials. The physical characterization of all the hollow spherical materials is presented in this work, which has confirmed their better electrochemical behavior in PEM water electrolyzer.     

Electrocatalytic performance of Ba-doped TiO2 hollow spheres in water electrolysis

Barium doped titania hollow sphere catalysts of various compositions were prepared and their electrocatalytic performance was evaluated in acidic media. Titania hollow sphere particles were prepared using poly (styrene–methacrylic acid) latex as template material, and BaCl₂ was used precursor material during barium doping over spheres. The morphology and structure of Ba/TiO₂ hollow spheres were characterized by BET, XRD, TGA and TEM analysis. XRD results had confirmed the presence of rutile TiO₂ and BaTiO₃ phases in the catalysts. The catalysts have shown almost similar surface area values (around 97 m²/g) irrespective of their compositions. On the other hand, surface area values were diminished remarkably with rise in the calcination temperatures. In TEM images, hollow sphere formation with uniform layer of barium over the spheres could clearly be observed. Diameter of Ba-doped TiO₂ hollow sphere was found 0.4–0.5 μm irrespective of the variation in calcination temperatures. In cyclic voltammograms, both the hydrogen and oxygen evolution peaks were present for all the hollow sphere samples; although the peak positions had changed to some extent for few samples. Anodic polarization curves have shown 60 mA cm⁻² current density for 20 wt% Ba/TiO₂ hollow sphere sample. Tafel slope is revealed as 122 mV for the same electrocatalyst. Barium doped titania hollow spheres have also shown long time electrocatalytic stability in acid solution.