Abstract
The modification of silica via incorporation of hydrated zinc oxide (HZnO) with different loadings was achieved using wet precipitation technique. After drying at room temperature, the obtained samples calcined at 105 degrees C and characterized using X-ray powder diffractometer, scanning electron microscopy, electron diffraction X-ray, transmission electron microscopy, Fourier transform infrared spectroscopy and BET. The data of characterizations indicated the well-distributed HZnO particles inside the silicate matrix with average particle size were lower than the detection limit of some characterization instruments. Furthermore, the modification with HZnO led to a noticeable decrease in BET surface area and the energy band gap due to the occupation of ZnO for interstitial positions inside the silicate matrix. The modified samples were successfully utilized in the adsorption and photocatalytic degradation of Methyl green dye as one of the cationic hazardous organic pollutants. The adsorption capacity of the sorbent catalyst was found to be 24.91 mg g(-1), while complete degradation of the (2 x 10(-4) mol L-1) dye was fulfilled in no more than 16 min. The influence of different experimental parameters as pH, temperature, concentration of the dye and dose of the catalyst was examined. The results obtained indicate that both adsorption and degradation of MG were a pH, dose and temperature dependent. The easiness of regeneration of the exhausted catalyst and its successive reuse confirmed remarkable economic efficiency.