Xanthan gum/titanium dioxide nanocomposite for photocatalytic degradation of methyl orange dye

Abstract

The present paper reports the synthesis of xanthan gum/titanium dioxide (TiO₂) nanocomposite for efficient visible light-induced degradation of highly toxic methyl orange dye. Synthesized xanthan gum/titanium dioxide nanocomposite showed good photocatalytic activity due to its high surface area, high light absorption ability and low energy potential between valence and conduction band. Tauc plot studies revealed the band gap of 2.8 eV for fabricated xanthan gum/titanium dioxide nanocomposite denoting its semiconductor nature. Numerous factors affecting the photodegradation rate such as dye concentration, pH, time, photocatalyst amount and hydrogen peroxide amount were also undertaken. The catalytic activity of xanthan gum/titanium dioxide nanocomposite was enhanced to great extent by the addition of hydrogen peroxide (H₂O₂). Around 89% dye degradation was observed by the xanthan gum/titanium dioxide nanocomposite in the presence of hydrogen peroxide as compared to 74% in absence of hydrogen peroxide. High R² value (0.974) for the degradation process in the presence of hydrogen peroxide generalized the fitting of the pseudo-first-order kinetic model. Present work will give deep insight into the utilization of xanthan gum/titanium dioxide based photocatalysts for the degradation of noxious methyl orange under natural sunlight irradiations.

Keywords: Hydrogen peroxide; Methyl orange; Photocatalysis; Photodegradation; Titanium dioxide.