Enhancement photocatalytic activity of spinel oxide (Co, Ni)3O4 by combination with carbon nanotubes

In this study, some types of composites consisting of multi-walled carbon nanotubes (MWCNTs) and spinel oxide (Co, Ni)3O4 were synthesized by simple evaporation method. These composites were characterized by UV–Vis diffuse reflectance spectroscopy, X-rays diffraction(XRD), Scanning electron microscopy (SEM) and specific surface area(SBET). The photocatalytic activity of the prepared composites was investigated by the following removal of Bismarck brown G (BBG) dye from its aqueous solutions. The obtained results showed that using MWCNTs in combination with spinel oxide to produced composites (spinel/MWCNTs) which succeeded in increasing the activity of spinel oxide and exhibited higher photocatalytic activity than spinel oxide alone. Also it was found that, multiwalled carbon nanotubes were successful in increasing the adsorption and improving the activity of photocatalytic degradation of Bismarck brown G dye(BBG). The obtained results showed that spinel/MWCNTs was more active in dye removal in comparison with each of spinel oxide and MWCNTs alone under the same reaction conditions. Also band gap energies for the prepared composites showed lower values in comparison with neat spinel. This point represents a promising observation as these composites can be excited using a lower energy radiation sources

Photocatalytic removal of reactive yellow 145 dye from simulated textile wastewaters over supported (Co, Ni)3O4/Al2O3 co-catalyst

The supported co-catalyst (Co, Ni)3O4/Al2O3 was prepared via using a co-precipitation method. Three sets of these materials were prepared by calcination at three different temperatures 500, 600, and 700°C. Crystal structure of the prepared materials was investigated using powder X-rays diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Atomic force microscope (AFM), and specific surface area (BET). The activity of the prepared catalysts was investigated by following both of photocatalytic and adsorption removal of Reactive yellow 145 dye (RY 145) from simulated industrial wastewaters. In this study, different reaction conditions were performed such as effect of pH of the reaction mixture, mass dosage of the used catalyst, and effect of temperature. In addition to that adsorption isotherms and reaction kinetics were investigated. Also the activity of these catalysts were investigated after cyclization of the used catalysts

Preparation and Characterization of Activated Carbon from Iraqi Khestawy Date Palm

This work includes a synthesis of three types of the activated carbon (AC) from three different positions from the same Iraqi Khestawy date palm. These three positions are the palm fronds (AC1), the date palm seeds (AC2), and the palm fiber (AC3). These three types of AC were synthesized by a physiochemical activation method using the same activator which was H3PO4. These materials were investigated using different techniques such as Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The adsorption activity of the synthesized AC samples was investigated by following the removal of both Bismarck brown G (BBG) and reactive yellow dye 145 (RY145). Both the kinetics of adsorption and the removal percentage of these dyes were investigated from the batch tests in this study. Different reaction parameters and conditions for adsorption processes were investigated. Also an investigation of both Langmuir and Freundlich adsorption isotherms was considered. The different physical properties of these materials were undertaken such as the point zero charges of the synthesized samples (PZCs), the percentage of humidity, and the adsorption capacity also being investigated. The activity of these materials in the removal of BBG from the aqueous solution was as follows: AC1>AC2>AC3

Equilibrium, isotherms and thermodynamic studies of congo red adsorption onto <i>Ceratophyllum Demersum</i>

82-87The adsorption of Congo red onto Ceratophyllum demersum (C. demersum) has been investigated. It is observed from the experiments that an adsorbent prepared from the Ceratophyllum demersum plant is effective for the removal of Congo red from aqueous solutions at room temperature. The adsorption of Congo red is found to be dependent on contact time, initial dye concentration and adsorbent dose. The results indicate that Ceratophyllum demersum has a strong capability of removing Congo red dye directly from contaminated water. Therefore, it can be concluded that Ceratophyllum demersum could be used for the removal of pollutants from aqueous solutions. The equilibrium adsorption data is analyzed using three common adsorption models: Freundlich, Langmuir and Temkin. The thermodynamic parameters ΔG°, ΔH°, and ΔS° are calculated for the adsorption of Congo red onto Ceratophyllum demersum. The Gibbs free energy change values show that the adsorption of Congo red onto Ceratophyllum demersum is spontaneous