A Novel Metal-Containing Mesoporous Silica Composite for the Decolorization of Rhodamine B: Effect of Metal Content on Structure and Performance.

A series of novel MnFe@SiO (x,y = 1-20%) nanocomposites were synthesized for the first time via the sol-gel/combustion method with different content of precursors (Mn and Fe acetate salts). The effect of precursor content and ratio on physicochemical properties were observed by various characterization methods. Moreover, Rhodamine B (RhB) was chosen as the target pollutant to test the performance of these nanocomposites under a photocatalytic Fenton-like reaction. The results showed that the nanocomposite morphology improved by increasing Fe and Mn content. In this study, interesting behavior was observed in BET results which were different from the fact that increasing metal content can decrease the surface area. This study revealed that one metal could be more critical in controlling the properties than another. Moreover, the precursor ratio appears to have a more tangible effect on the surface area than the effect of precursor content. Among all synthesized nanocomposites, MnFe@SiO showed the highest surface area of 654.95 m/g. At optimum batch conditions (temp = 25 °C, catalyst dosage = 1 g L, HO = 75 mmolL, and initial RhB concentration = 50 mg L), complete removal (simultaneous adsorption/degradation) occurred using MnFe@SiO at neutral pH. This study showed that the designed nanomaterial could be used as a dual functional adsorbent/photocatalyst in different environmental applications.