Borax-cross-linked guar gum-manganese dioxide (GGB-MnO2) composite was synthesized using an environmentally friendly<br>synthesis route and investigated for its efficiency of decolorizing methylene blue (MB) dye solution by an ultraviolet-visible<br>(UV-Vis) spectrophotometric study. The GGB-MnO2 composite was characterized using X-ray diffraction (XRD), field emission<br>scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectroscopy, Fourier-transform infrared (FTIR)<br>spectroscopy, and thermogravimetric analysis (TGA). The composite (1.2 g/L) exhibited excellent oxidative decolorization of<br>MB (30 mg/L, 50 mL) solution to over 99% in 6, 13, and 40 min at pH 4, 7, and 10, respectively. The complete decolorization of<br>MB occurred via a catalytic adsorption-oxidation-desorption mechanism. The GGB-MnO2 composite showed very good<br>reusability and was stable after ten successive cycles with negligible losses of the decolorization efficiency.
|State||Published - 2019|