Facile synthesis of chitosan-La-graphite composite and its influence in photocatalytic degradation of methylene blue.

Integrated photocatalytic composite adsorbents (IPCA) are used to degrade toxic organic and inorganic compounds in presence of UV/visible light irradiation. The compound preserves all the existing features of individual components and at the same time overcome drawbacks like rapid recombination of photogenerated electrons, low absorptivity and hindrance effect of the photocatalyst. Herein, an integrated Photocatalytic Chitosan-La-Graphite composite adsorbent was synthesized and the resultant composites were characterized by FTIR, XRD, TGA, EDX and SEM analysis. The UV-visible diffusion reflectance spectroscopy (UV-vis DRS) was used for the band gap measurement and it was found to be 3.2 eV. An aqueous solution of methylene blue (MB) dye (30 mL of 100 mg/L) was used to study the photocatalytic efficiency of the prepared IPCA. The Chitosan-La-Graphite Composite (CS-La-GR) (100 mg of dosage) exhibits enhanced photocatalytic degradation efficiency (93.5% in 40 min) for Methylene blue under UV light irradiation. The highest photodegradation was due to the stronger adsorption of MB dye on the surface of highly porous IPCA. Moreover, the reactive species, OH radical and O radical ions play a major role in the photocatalytic degradation of Methylene blue over composite photocatalyst.