Madhukar Navgire

Photodegradation of Molasses by a MoO3-TiO2 Nanocrystalline Composite Material

A MoO3-TiO2 nanocrystalline composite material was prepared by a simple sol-gel method. The synthesized material was characterized by X-ray diffraction, scanning electron microscopy with an electron dispersion spectroscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Melanoidin is a dark brown pigment found in wastewater from the sugar industry and it pollutes water. This polluted water is generally referred to as molasses and it undergoes fermentation and is solely responsible for water, soil, and air pollution. The synthesized catalytic material was found to be effective in degrading molasses under UV-visible radiation. Analysis of treated and untreated molasses was carried out by measuring its color, chemical oxygen demand, biological oxygen demand, pH, and total dissolved solid. Results from these analyses indicate the effective photodegradation of the molasses. This methodology has several advantages such as high photocatalytic activity, non-toxicity, cleanliness, and reusability of the catalytic material.

β-Cyclodextrin supported MoO3–CeO2 nanocomposite material as an efficient heterogeneous catalyst for degradation of phenol

With the aim of efficiently degrading organic pollutants through an easily operated procedure, a series of MoO3–CeO2 and β-cyclodextrin supported MoO3–CeO2 nano-composite materials were synthesized by using a co-precipitation method. A surfactant such as Cetyl Trimethyl Ammonium Bromide (CTAB) was used during the synthesis of this nano-composite material. These prepared catalysts are thoroughly characterized by various techniques such as XRD, BET, FT-IR, pyridine adsorbed FT-IR, Raman spectroscopy, SEM and TEM. The XRD study results suggested the formation of nanocrystalline materials which is also clearly observed from the SEM and TEM analysis. Raman measurements disclosed the presence of oxygen vacancies and lattice defects in all synthesized nano-composite samples. The catalytic activities of the synthesized materials were successfully tested for the degradation of phenol by using hydrogen peroxide at room temperature. It is surprising that the phenol degradation efficiency of the β-cyclodextrin supported MoO3–CeO2 nano-composite material is exhibited higher than that of other materials, which has been mainly attributed to the promoting effect of β-cyclodextrin. The degradation reaction is carried out at room temperature with continuous stirring and without light irradiation. Therefore, this degradation reaction is different from conventional heterogeneous catalysis or photocatalysis, in which the pollutants cannot be degraded completely, but it may transform from one phase to another phase. The gradual decrease in COD value shows the degradation of phenol that leads to the conversion of organic compounds into harmless gaseous CO2 and inorganic ions. Thus, this reported phenol degradation reaction is a quite promising green technology, which could be widely applied in practice.

Effect of Nanocrystalline Composite Fullerene doped MoO3-TiO2 material on Photoassisted Degradation of Alizarin Red S Dye

ABSTRACT A fullerene-doped MoO3-TiO2 nanocrystalline composite material was prepared by sol-gel method. The catalyst prepared was characterized by means of some modern sophisticated techniques such as XRD, SEM-EDS, FT-IR, TEM, BET, and TGA analysis. It shows successful synthesis of porous, nanocrystalline material with higher surface area. The photodegradation of Alizarin red S was used as a model reaction to study the activity of the synthesized catalyst. The high photodegradation activity obtained using the fullerene-doped MoO3-TiO2 mainly due to the more adsorption of the dye (Alizarin red S) on the large surface area of catalytic material.

Synthesis and Characterizations of Carbon Doped MoO3-TiO2 Nanocrystalline Composite Materials

The series of carbon doped MoO3-TiO2 nanocrystalline composite material was prepared by using simple sol-gel method. The carbon material used was obtained from natural sources as Acacia Arabica plant. The synthesized materials were characterized by various sophisticated techniques. The crystalline nature of composite material was increased with addition of carbon. The 3 wt% carbon doped MoO3-TiO2 material has particle size in around 9–12 nm. This material absorbed light in more visible region at 457 nm and has band gap 2.71 eV. Thus material may be use as catalyst for photodegradation of pollutant.

Novel highly stable β-cyclodextrin fullerene mixed valent Fe-metal framework for quick Fenton degradation of alizarin

β-Cyclodextrin (β-CD) supported magnetic nanoscaled fullerene/Fe3O4 (CDFMNPs) and fullerene/Fe3O4 (FMNPs) composites were prepared and characterized. These composites can be utilized as heterogeneous catalysts for the Fenton oxidation reaction to degrade alizarin in aqueous solutions. The saturation magnetization (Ms) value of quasi-spherical CDFMNPs was found to be 13.16 emu g−1 and their diameter was in the range of 25–30 nm. The catalytic activities of the prepared materials were tested with varying conditions of pH, amount used and the concentration of H2O2 for degradation of alizarin at room temperature. The exceptionally high degradation efficiency of CDFMNPs was observed for alizarin at pH 3 with 2.0 g L−1 catalyst and 25 mM of H2O2. The increased oxidative degradation efficiency is attributed mainly to the formation of active hydroxyl radicals (˙OH) on the surface of the catalyst, which are generated by the active decomposition of H2O2 by the solid heterogeneous catalyst and the promoting effect of β-CD. CDFMNPs can be magnetically separated and the catalyst was found to be reusable and stable for five successive runs with no significant loss of catalytic activity. In the magnetic environment of Fe3O4 nanoparticles, fullerene has a crucial role to enhance the activity by increasing the stability with nominal iron leaching. Based on mass analysis of alizarin degradation, the formation of aliphatic acids and monocyclic compounds through phthalic anhydride and di-methyl phthalate established the proposed degradation path.