▎ 摘　　要

NOVELTY - A nanocomposite comprises zinc oxide/bismuth oxyiodide (BiOI)/graphene nanocomposite showing main diffraction peak in X-ray diffraction pattern. USE - Nanocomposite used for photocatalyst degradation of malachite green dye. Uses include but are not limited to industrial effluents containing dyes emanating from textile mills and food industries causing contamination of surface and ground water. ADVANTAGE - The nanocomposite is easy to synthesize as all raw materials are easily available and process is simple and easy, shows high efficiency in degrading malachite green within 2-3 hours and economical. The photocatalysts can be regenerated and re-used, and enhancing economic viability of the process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for synthesis of the nanocomposite, which involves preparing zinc oxide solution and doping with samarium (Sm3+) ions and 7-9% zinc nitrate in distilled water containing 1-3%, optimally 2% sodium hydroxide, adding samarium nitrate (SmNO3) at concentration of 1x 10-5 mol dm-3 and mixing properly by stirring for 5-6 minutes followed by ultrasonication for 1-3 hours, optimally 2 hours at 50-70 degrees C, optimally 60 degrees C and drying to give powder, synthesizing bismuth oxyiodide (BiOI)-graphene solution by dissolving 3-5%, optimally 4% bismuth(III) nitrate and 1-3%, optimally 2% potassium iodide (KI) in distilled water, adding graphene at concentration of 0.5-1.5%, optimally 1% and mixing by stirring for 5-6 minutes, and synthesizing of ZnO/BiOI/graphene nanocomposite samarium ion (Sm3+) doped ZnO solution is mixed with bismuth oxyiodide (BiOI)-graphene solution in the ratio 2:1 (v/v) with continuous stirring followed by ultrasonication for 1-3 hours, optimally 2 hours at 70-90 degrees C, optimally 80 degrees C and drying to give nanocomposite.