Enhancement of adsorption efficiency of methylene blue on Co3O4/SiO2 nanocomposite

Single and well-crystalline Co3O4 phase imbedded in an amorphous SiO2 matrix has been obtained by novel aqueous solution method. The structural and morphological properties are investigated using X-ray diffraction, Fourier transform infrared spectrometer, and N-2 adsorption-desorption techniques. The apparent crystallite size for Co3O4 was found to be about 13.5 nm, which elucidates the rule of poly ethylene glycol in preventing particle's agglomeration; moreover, the pours structure of the composite enhances its adsorption ability. Co3O4/SiO2 has a high ability to absorb methylene blue from an aqueous solution. The removal percent of Methelene blue (MB) by Co3O4/SiO2 has reached 95.7%. The effect of various experimental parameters, such as initial dye concentration, contact time, and dose were investigated. Co3O4/SiO2 nanocomposite shows high adsorption capacity of 53.87 mg g(-1), which is larger than the adsorption capacity of MB on other materials. Both of Langmuir and Freundlich models were used to analyze the equilibrium adsorption data. The pseudo-second-order model was found to be the most appropriate model to represent the present data. Co3O4/SiO2 nanocomposite material is proposed as a potential adsorbent for water treatment.