Solvent Controlled Synthesis of CaO–MgO Nanocomposites and Their Application in the Photodegradation of Organic Pollutants of Industrial Waste1

摘要

Conventional heating method and hydrothermal method were used for the synthesis of CaO nanoparticles and CaO/MgO nanocomposites under solvent control conditions. Ca(NO_3)_2 and Mg(NO_3)_2 were used as precursors, amyl alcohol as surface directing agent and NaOH as source of OH~–. Different sam- ples of CaO were prepared by conventional heating method in order to investigate the effect of calcination temperature and stirring time. Similarly two different kinds of sets of CaO as well as of CaO/MgO were syn- thesized under hydrothermal conditions for the investigation of effect of solvent and temperature on catalytic efficiency. Characterizations of these samples were carried out by Powder X-ray Diffractions (XRD), Thermo Gravimetric Analysis (TGA), Field Emission Scanning Electron Microscope (FESEM) Energy dispersive X-ray (EDX) and Fourier Transformed Infrared spectroscopy (FTIR). The synthesized samples of CaO and CaO/MgO were used to degrade methylene blue under UV-Visible conditions, which is an organic pollutant of waste from industries and causing serious health problems. First order data for degradation for methylene blue at λ_(max) = 665 nm was used to quantify the degradation. Effect of solvent was found to be prominent in all samples. Similarly effect of temperature variation was also pronounced on catalytic efficiency as indicated by value of k.