▎ 摘　　要

Indigo Carmine dye is very toxic in nature and it is widely used for many industrial purposes especially in textile industries. The use of environment-friendly catalytic-adsorbent materials in the treatment of Indigo Carmine was studied in this experiment. The nanocomposite used in this study was prepared using lanthanum oxide nanoparticle-graphene oxide nanocomposite coating on the pyrolyzed biochar of sawdust waste, and as a result, both adsorption and photodegradation of dye materials will be observed simultaneously. The use of the nano-coated biochar in removal of Indigo Carmine was evaluated in the presence of various UV radiations (UV-A, B, C) and visible radiation (white light). At pH 4 with temperature of 298 K, the nano-coated composite can remove 30.433 mg/g of 20 mg/l dye of concentration in 120 min equilibrium time in the presence of visible radiation. This study will provide an area of research in the removal of toxic dyes and utility of combining the process of adsorption with photo-/UV degradation. The experimental results also suggested that the use of visible radiation can be a better alternative for the removal of Indigo Carmine present in solution.