Synthesis and Application of a Powerful Heterogeneous Photo-Fenton Catalyst Based on rGO/g-C <sub>3</sub> N <sub>4</sub> /Fe <sub>3</sub> O <sub>4</sub> /tiO <sub>2</sub> Nano-Composite for the Removal of Sewage Contaminants
Masoumeh Ghalkhani, Hossein Charkhan, Maryam Sabbaghan
Abstract
The reduced GO/g-CN/Fe 3 O 4 nano-composite was prepared by the co-precipitation of pre-hydrolyses ferric and ferrous salts in the presence of GO/g-CN hybrid. Structural and morphological characterization of the synthesized rGO/g-CN/Fe 3 O 4 /TiO 2 nano-composite were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Their photo-Fenton catalytic performance under UV–visible light irradiation was evaluated by UV–vis spectrophotometry and electrochemical methods. The influence of heterogeneous catalyst composition on the MB degradation efficiency was examined and optimized. The highest MB degradation efficiency of ternary rGO/g-CN/Fe 3 O 4 was 53% under UV light. Addition of nano TiO 2 to the nano-composite effectively improved its photo-Fenton degradation efficiency (up to 97% within 20 min). As excellent conductive carrier, rGO connected g-CN to TiO 2 and effectively separated photo-created electrons and holes. Uniform dispersion of g-CN on the rGO surface caused full harvest of incident light and more efficient interaction with pollutants. The significant improvement of photo-Fenton catalytic effect of rGO/g-CN/Fe 3 O 4 /TiO 2 is attributed to the synergetic interaction and availability of the active catalytic centers that effectively facilitated the Fe 3+ /Fe 2+ recycling. Experimental results confirmed the promising dual purpose application, photo-Fenton and adsorption properties of rGO/g-CN/Fe 3 O 4 /TiO 2 nano-composite in wastewater treatment.